2. Strobes and Guide NumbersFinding the guide number of a strobe| 00:00 | In this movie we're going to begin the hands-on
process of exploring how to really master your flash.
| | 00:06 | To do that, we'll start by explaining how you
can find your flash's guide number and what
| | 00:11 | to do with it once you have it.
| | 00:13 | Small strobe manufacturers use the term guide
number to rate the power of their pocket strobes.
| | 00:18 | A guide number is a numerical expression
of the ability of the flash to create
| | 00:22 | at a normal exposure at any given ISO.
| | 00:25 | When you leaf through your manual, you should
find the table that looks something like this.
| | 00:30 | Because a higher guide number means more power
and more power means a higher value, manufacturers
| | 00:36 | tend to inflate their published guide numbers.
| | 00:39 | This means that if you're serious about
getting consistently good manual flash exposures,
| | 00:44 | you should perform your own guide number test.
| | 00:47 | Another reason to perform your own guide
number test is because a guide number is dependent
| | 00:51 | upon the accuracy of the ISO
rating of the camera sensor.
| | 00:55 | Same flash unit when placed on two
different cameras will have two different effective
| | 00:59 | guide numbers if the
camera's sensors are not calibrated.
| | 01:04 | You can determine your own guide number by
identifying the best exposure from a series
| | 01:08 | of portraits taken while maintaining a consistent
flash to subject distance and bracketing the aperture.
| | 01:15 | We want results that aren't contaminated by
ambient light or too much light bouncing off
| | 01:20 | of a white or pale colored walls and ceilings.
| | 01:23 | So find a dimly lit room with some breathing
room overhead and on either side of your subject.
| | 01:28 | That's why we pulled the curtains here in the studio
and covered part of the floor with the black duvatine.
| | 01:34 | Now is as good as time as any to get
used to working with your flash off camera.
| | 01:37 | So use a radio slave or a sync cord to
allow you to get your flash out of the hot shoe
| | 01:43 | and onto a light stand.
| | 01:45 | The guide number test consists of a series
of images beginning at f/22 and opening up
| | 01:51 | in third stop increments all the way to f/56.
| | 01:55 | Follow the recipe, and when you're finished,
you'll have a series of 13 portraits, one
| | 01:59 | of which will reveal your guide number.
| | 02:02 | The PDF for this course will have the
following guidelines included for reference.
| | 02:07 | Place the flash exactly
10 feet from your subject.
| | 02:10 | This is going to make
calculating your guide number easier.
| | 02:13 | Place the flash in full manual mode, this is designated
by an icon on the back of a display, reading 1/1.
| | 02:21 | Now, it's important to know that most small
strobes have reflectors and lenses that move
| | 02:25 | to match the angle of the coverage of the lens.
| | 02:28 | When the zoom head mechanism that's place
in a telephoto setting, the resulting beam
| | 02:32 | of light is more concentrated than one
when the head is zoomed out to cover the field
| | 02:37 | of view of a wide-angle lens.
| | 02:39 | You can hear the gearing mechanism that drives
the lens move as we change the focal lengths.
| | 02:45 | This is a good thing because it conserves
energy by illuminating only what's seen by the chip.
| | 02:50 | But it means that the same flash unit will have a
different guide number at every zoom head setting.
| | 02:56 | So for the sake of this test set the
zoom head on the flash to 50 millimeters.
| | 03:01 | Frame up a loose head and shoulder portrait.
| | 03:04 | If you're shooting in a normal or a wide lens,
this is going to require that you get between
| | 03:08 | a flash and the subject.
| | 03:11 | So make sure your head doesn't contaminate
your results by casting a shadow on your subject.
| | 03:16 | Make sure the subject is wearing a white shirt,
because we want to determine which exposure
| | 03:20 | begins to lose detail in
the texture or the fabric.
| | 03:25 | Subject should be holding a gray card at an
angle that prevents a hotspot from being reflected
| | 03:29 | off of the card and onto the lens.
| | 03:33 | Place the camera in manual mode and set the
white balance on your camera to the flash setting.
| | 03:39 | Set your camera at ISO 100.
| | 03:40 | If your camera doesn't go that low and the
table in your flash manual list the GNs at
| | 03:45 | ISO 100, you will have to do simple conversion
to compare your results to the guide number table.
| | 03:51 | But don't worry, we will take a look at how
to make that conversion later in this chapter.
| | 03:56 | Shoot at your camera's sync speed, and if
you're using a radio slave then shoot at a
| | 04:01 | third stop slower to account for the slight
delay that sometimes occurs in the radio circuitry.
| | 04:07 | In any event, the use of the highest possible
shutter speed will illuminate ambient lighting
| | 04:11 | conditions, provided you're shooting in a
dimly lit room as previously called for.
| | 04:17 | Finally, allow the flash to
recycle completely between exposures.
| | 04:22 | After the beep or ready light, count to five
and change your aperture before shooting again.
| | 04:27 | This ensures consistent results by allowing the
capacitor to fully recharge between exposures.
| | 04:33 | Now it's your turn. Just a reminder, take your
first shot at f/22 and bracket your exposures
| | 04:39 | by opening up your aperture in third
stop increments all the way down to f/56.
| | 04:45 | Once you've generated your set of 13 images, it's time
to analyze them, and we'll do that in the next movie.
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| Analyzing the results of the guide number test| 00:00 | So we just finished
shooting our guide number test.
| | 00:02 | I took a series of portraits of Gabby bracketing
the aperture, and now we're going to see how
| | 00:08 | to use those images to
establish what are guide number is.
| | 00:11 | So let's get straight into that.
| | 00:14 | So here are the images that we just took for the guide
number test, and you can see that the bracketing worked.
| | 00:20 | We went from f/22 all the way down to 5.6.
| | 00:24 | Clearly, the first five or six of these are underexposed,
and the last three or four are overexposed.
| | 00:30 | So just by eyeballing it, I can tell.
| | 00:33 | I'm going to open up this image,
the one taken at f/11.
| | 00:36 | I'm going to open up the
one at 10, at 9, and at f/8.
| | 00:43 | So let's just take a look at these guys, and
we're going to do that in the Raw processor.
| | 00:50 | So what I'm looking for is to see which
exposure holds detail in the white shirt and gives
| | 00:56 | me values of roughly 245 in the brightest spot,
because then I can work with that exposure
| | 01:02 | to really give me a good tight exposure.
| | 01:05 | Here you can see I'll be
looking at the RGB values up here.
| | 01:10 | I am going to scroll the
cursor over the white shirt.
| | 01:12 | I'm looking to get close
to 245 in the highlights.
| | 01:19 | I'm nowhere near anywhere in the white shirt, and
even in the white banding on the gray card it's low.
| | 01:26 | The gray card itself in the gray area looks
pretty close to what medium gray would call
| | 01:32 | for, but what I'm really interested in again is getting
the highest values of white without blowing the detail.
| | 01:39 | Here I'm looking at the image that was
taken at f/10, scrolling through the highlights
| | 01:45 | and white shirt, still not getting to 245.
Just take a look at the image at 9.
| | 01:51 | Here I'm getting close 242.
I hit getting in here.
| | 01:57 | Let's see let's go back here.
| | 01:59 | So you can see the gray value is getting pretty
high, but this is the image that I'm liking so far.
| | 02:06 | It hit a hotspot here at 245 at one point.
| | 02:09 | Now I'm going into the exposure taken at f/8,
and I'm getting really close to blowing the highlights.
| | 02:16 | You can see that by looking at the histogram where
I pushed all the way over to the right-hand side.
| | 02:23 | The blacks themselves are not deep enough.
| | 02:27 | Where I'm getting black
over here is from the curtains.
| | 02:31 | The exposure that I'm going to choose based
on holding detail on the white close to medium
| | 02:36 | gray is the exposure taken at f/9.
| | 02:41 | So what I'm going to do to find my guide number is
multiply the aperture times the flash to subject distance.
| | 02:48 | So if you recall, we shot at 10 feet.
The exposure that I like is at f/9.
| | 02:55 | So my guide number is 90.
| | 02:58 | This is the image that the
manufacturer's guide number would have yielded.
| | 03:02 | The manual calls I think for
a guide number of 136 or 138.
| | 03:07 | Here we are clearly
underexposed at 10 feet at f/14.
| | 03:12 | So this is the reason that we suggested
that you do your guide number test, because if
| | 03:16 | you were to rely on the manufacturer, you'd be a full stop and
a third underexposed whenever you're shooting manual flash.
| | 03:25 | Now we've taken a look at the
results of the guide number test.
| | 03:28 | We saw the best exposure
occurred at the aperture value of f/9.
| | 03:32 | I multiplied that aperture value by my
flash to subject distance of 10 feet to give me
| | 03:37 | a guide number of 90 for my
flash on my camera at ISO 100.
| | 03:42 | The manufacturer's guide number for the same model is
right around 140, which is 1 & 1/3 stops brighter.
| | 03:49 | Therefore, if I were using the published
numbers, I'd be underexposing my flash images.
| | 03:55 | That's the reason I encourage
you to do this test for yourself.
| | 03:57 | Next, I'll get into more detail about the guide number
and how and why it works in manual flash photography.
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| Understanding how the guide number is used| 00:00 | In this movie, we are going to
look at how the guide number is used.
| | 00:04 | The test we performed and analyzed in the
previous movies gives us a guide number that
| | 00:09 | is unique to our small strobe.
| | 00:12 | The guide number is similar to exposure value
because it considers how much light is available
| | 00:16 | based on the power output of our strobe and
how much light is required by the sensor as
| | 00:21 | determined by our camera's ISO setting.
| | 00:24 | Remember, when we did the Guide Number test,
the formula that we used was guide number
| | 00:28 | equals Flash to Subject Distance times Aperture.
| | 00:32 | The guide number is constant
until you change your ISO.
| | 00:36 | So, once you know your guide number, you
can plug it in to the guide number Formula to
| | 00:40 | solve for either Flash to
Subject Distance or for Aperture.
| | 00:44 | So, Flash to Subject Distance equals
Guide Number divided by Aperture,
| | 00:48 | or Aperture equals Guide Number
divided by Flash to Subject Distance.
| | 00:54 | When I'm out shooting, I'm either going to
select my aperture for depth-of-field reasons
| | 00:58 | which then dictates how far I put my flash
from the subject, or instead I may choose to
| | 01:04 | place my flash a certain distance from the subject
because of space constraints or for creative reasons.
| | 01:10 | That then determines my aperture.
So, you know your guide number.
| | 01:15 | Then you're going to choose either your
aperture or your flash to subject distance.
| | 01:19 | Once you've done that, solving
for the missing variable is easy.
| | 01:24 | To help remember how these three variables relate
to one another, we can think of them as a triangle.
| | 01:29 | For example, let's say our guide number is 100.
| | 01:32 | If we're shooting at f/8, we simply divide 100 by 8
giving us a flash to subject distance of 12.5 feet.
| | 01:40 | If, on the other hand, we decide to put our flash 16 feet
from the subject, we'll end up shooting at f/6.3.
| | 01:48 | With practice and a thorough working knowledge
of the aperture and flash to subject distance scales,
| | 01:52 | this process becomes second nature.
| | 01:55 | It's helpful to remember that the numerical
structure of the flash to subject distance
| | 02:00 | and the aperture scales are identical
because they're based on the square root of two.
| | 02:04 | So, now let's try a practical
application to see how this all fits together.
| | 02:10 | As you can see, we're just about set up to
take a quick head and shoulder portrait shot
| | 02:16 | of Gabby, our model here.
| | 02:19 | But what we're going to do right now is
illustrate the interchangeability of the aperture and
| | 02:25 | flash to subject distance.
| | 02:27 | And we're going to start by dividing my
guide number of 90 on this flash by the aperture
| | 02:35 | that I want to start
shooting at, and that's f/22.
| | 02:37 | So, when I do that division, I know that I have to
place my flash 4 feet from the subject. So, I do that.
| | 02:46 | I make sure it's aimed in the right direction.
Confirm that I'm shooting at 22.
| | 02:59 | Give me a big smile, that's nice!
| | 03:02 | And as expected, we get a beautiful
perfectly-exposed image.
| | 03:07 | But I can tell that I blew her away with
that full power flash pop from 4 feet away.
| | 03:12 | So, I could address that simply by reducing
the illumination on the flash or the power
| | 03:17 | on the flash and opening up the lens.
| | 03:20 | But because the purpose of this exercise is
to illustrate the interchangeability of flash
| | 03:25 | to subject distance and aperture, we're
going to take that approach to doing this.
| | 03:29 | So, what I want to do is reduce the
amount of illumination on Gabby by 3 stops.
| | 03:34 | And to do that, I'm simply going to walk the
flash back from 4 feet to 5.6 feet to 8 feet,
| | 03:41 | and finally to 11 feet.
| | 03:43 | I'm going to go back to my camera, and I'm
going to open up the lens from f/22 to f/16
| | 03:52 | to f/11 to f/8, and I'm going
to fire off another exposure.
| | 03:57 | And indeed, I get another
perfectly illuminated picture.
| | 04:02 | The skin tones are identical.
| | 04:04 | What you're going to notice is that
the background tonality is changed.
| | 04:09 | You may have also noticed that I didn't do
any division after I placed my flash initially.
| | 04:15 | And the reason that I am able to get away
with that is because I've become so familiar
| | 04:19 | with the flash to subject distance scale, and the
aperture scale, and I know how they interrelate.
| | 04:26 | When I started out, I did indeed do the long-
hand math, and that's probably the way
| | 04:30 | that you're going to get started.
| | 04:32 | But no matter which approach you take, as long as you
do it correctly, you're going to get good exposures.
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| Understanding why guide number math works| 00:00 | In this movie, I'm going to take a moment
to review how the flash to subject distance
| | 00:04 | and the aperture scales relate to one another.
| | 00:06 | And then we're going to look at how we can
use this information to maintain equivalent
| | 00:10 | exposures when we're working with small strobes.
| | 00:14 | Remember, the square root of 2 is an integral
part of the Inverse Square Law, which we use
| | 00:18 | to calculate the change in illumination
when the flash to subject distance changes.
| | 00:23 | It's also an integral part of
calculating the size of an aperture.
| | 00:27 | And an aperture is nothing more than a circle,
and you may recall that the formula for the
| | 00:31 | area of a circle is Pi R squared.
| | 00:35 | Because Pi is a constant that doesn't
change no matter how big or how small the circle,
| | 00:40 | we can ignore it while determining the
relative change in the size of the aperture.
| | 00:45 | You probably already know that if we double
the area of the circle, we'll create a one
| | 00:49 | stop increase in the size of the aperture.
| | 00:51 | And life would really be simple if the formula
read area equals Pi times R because each time
| | 00:58 | the radius is doubled, the
area of the circle would double.
| | 01:01 | In that world, a one-stop change
from a 5 would be f/10 instead of 7.1.
| | 01:08 | Unfortunately, the formula
demands that we use R squared, not R.
| | 01:13 | This means that the area doubles when
the radius increases by the square root of 2.
| | 01:19 | If you look carefully, you'll notice that
one-stop increments on the aperture scale
| | 01:23 | are separated by a factor 1.4, which you'll
recall from our previous discussion of the
| | 01:29 | Inverse Square Law is
equal to the square root of 2.
| | 01:33 | As a result, 1.4 dominates the guide number
scale, the flash to subject distance scale,
| | 01:39 | and the aperture scale.
| | 01:41 | When we look at them together, their
similarities become obvious and therefore useful.
| | 01:47 | An understanding of how the square root of 2,
or 1.4, is used to determine the change in
| | 01:53 | both the aperture size and the flash to
subject distance helps you to use the scales to solve
| | 01:59 | problems more quickly, even when
shooting in TTL mode or using big strobes.
| | 02:04 | We alluded to this earlier, but now let's
demonstrate the results of making offsetting
| | 02:09 | adjustments to flash to
subject distance and aperture.
| | 02:13 | Remember, the guide number for
this flash on this camera is 90.
| | 02:18 | So, I started shooting at f/18
from a distance of 5 feet.
| | 02:22 | I opened up the lens in one-third stop
increments, while compensating by backing up the flash
| | 02:28 | in one-third stop increments until I got to a
distance of 18 feet, and an aperture of f/5.
| | 02:35 | Now, let's review the series of images.
As expected, we see the depth of field changes.
| | 02:41 | In addition because I move the flash, the
position of the shadows changed and the level
| | 02:47 | of illumination on the background changed.
| | 02:49 | However, if you focus on her face, you'll
see that I was able to maintain equivalent
| | 02:54 | exposures throughout the entire series.
| | 02:57 | This proves that a change in aperture when
offset by an equal change in the flash to
| | 03:01 | subject distance results
in an equivalent exposure.
| | 03:05 | Once you've learned the scales, and you know
your guide number, you'll know exactly where
| | 03:09 | to place the flash to match your aperture.
| | 03:11 | At first, this may sound like a lot of work
in a TTL enabled world, but when you get the
| | 03:16 | hang of it, you can really move fast
in response to changing circumstances.
| | 03:20 | So, no matter what your shooting style, there are times
when this level of manual control can really save the day.
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| Making calculations based on ISO| 00:00 | One of the more challenging things for newcomers
to wrap their heads around is the notion that
| | 00:04 | when you change your ISO, your guide number
has to change with the same number of stops
| | 00:10 | in the same direction.
| | 00:12 | Increasing the ISO has a same effect as
physically increasing the illumination level.
| | 00:17 | We know this is true because to make an equivalent
exposure, we have to adjust our shutter speed
| | 00:22 | or our aperture to allow
less light to reach the sensor.
| | 00:26 | The same thing is true of our flash.
| | 00:28 | Since we can't use the shutter to reduce the
amount of strobe light that reaches a chip,
| | 00:33 | we either have to stop down the lens or increase the
flash to subject distance when we increase the ISO.
| | 00:40 | Increasing our ISO by one stop has a same effect
as increasing the power of the flash by one stop.
| | 00:46 | So, when our ISO changes, our guide number has to change
by the same number of stops in the same direction.
| | 00:54 | Let's take a look at an example and
assume our guide number is 110 at ISO 100.
| | 01:00 | One combination of aperture and flash to
subject distance that provides a normal flash exposure
| | 01:05 | is f/11 at a distance of 10 feet.
| | 01:08 | We know that if we change the ISO to 200 and do
nothing else, we will overexpose the flash by one stop.
| | 01:14 | Therefore, if we choose to leave the flash
at 10 feet, we must close down the aperture
| | 01:19 | by one stop to f/16 to
maintain an equivalent exposure.
| | 01:24 | Therefore, the new guide number at ISO 200
is 160, f/16 times 10 feet equals 160.
| | 01:34 | There's a one-stop difference
between ISO 100 and 200.
| | 01:38 | There's a one-stop difference
between f/11 and f/16.
| | 01:43 | There's a one-stop difference between 11 feet
and 16 feet, and there's a one-stop difference
| | 01:48 | between guide number 110 and guide number 160.
Now, let's prove this a different way.
| | 01:55 | Once again, assuming our
guide number is 110 at ISO 100.
| | 02:00 | Remember, one combination of aperture and
flash to subject distance that will provide
| | 02:05 | a normal exposure is f/11
at a distance of 10 feet.
| | 02:10 | If we change the ISO to 200 and choose to
shoot at f/11, we have to move the flash back
| | 02:15 | one stop from 10 feet to 14 feet
to maintain an equivalent exposure.
| | 02:21 | Once again, the new guide number at ISO 200 is 160,
f/11 time 14 feet equals 154, rounded to 160.
| | 02:32 | So just to wrap things up, here's the guide
number scale on one-third stop increments.
| | 02:36 | Notice how it compares so
neatly to the aperture scale.
| | 02:40 | As you can see, the values are very interrelated.
Making adjustments to one requires an adjustment to another.
| | 02:47 | But the guide number scale helps you to
make these adjustments without having to think
| | 02:51 | about all of the underlying math.
| | 02:53 | As you'll see later in the shoot chapter,
working knowledge of this relationship allows
| | 02:58 | me to nail my exposures very quickly and to work with
confidence while making adjustments on the fly.
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| Understanding power ratios| 00:00 | At this point in the course, we've
discussed how the scales are calculated.
| | 00:04 | We know what a guide number is and how the
math allows us to create equivalent flash
| | 00:08 | exposures by making offsetting moves with our ISO,
our flash to subject distance, and our aperture.
| | 00:15 | We've seen examples of how it
works in a controlled setting.
| | 00:18 | We'll also see how to apply this
information during a live model shoot.
| | 00:22 | Troubleshooting lighting problem shouldn't be
a trial and error, hair-pulling, time-wasting,
| | 00:26 | iterative process of elimination.
| | 00:29 | Now, we're going to end our primer on
small strobes by introducing power ratios.
| | 00:34 | Power ratios are manual settings on the
flash that allow you to reduce the guide number
| | 00:38 | by shooting at less than full power.
| | 00:41 | They provide another level of control that you
can use to make your manual flash more versatile.
| | 00:46 | Well, small strobes and strobe packs give
you the option of shooting at full power
| | 00:51 | or the variety of lower outputs.
| | 00:53 | In the case of most small strobes, you can
adjust the flash in third stop increments
| | 00:58 | all the way down to 164th power.
| | 01:00 | This represents a six-stop exposure range that is
achieved by decreasing the duration of the flash pop.
| | 01:06 | This allows you to save batteries, reduce
recycle time, use a shallower depth of field,
| | 01:12 | work in smaller spaces, or quickly manage lighting ratios
and complex scenes if you're using multiple strobes.
| | 01:19 | You'll see this in action in the next chapter.
| | 01:21 | But now let's tie this
back to guide numbers and ISO.
| | 01:24 | When you change the power ratio, you're changing
the guide number by an equal number of stops.
| | 01:30 | This concept is simple and familiar.
| | 01:32 | The application of the theory would be just as easy if
ISOs and guide numbers shared the same numerical scale.
| | 01:39 | Unfortunately, they don't.
| | 01:41 | Let's say your flash has a guide
number of 100 at an ISO of 100.
| | 01:46 | On the face of it, logic demands that if we
reduce the power output by one stop by cutting
| | 01:51 | the power ratio in half, the new
guide number should be 50. But it's not.
| | 01:56 | When we review the guide number scale,
we see that 50 is two stops below 100.
| | 02:00 | Instead, the new guide number is 71, which
is one stop lower than guide number 100.
| | 02:05 | So, you have to do a little mental gymnastics
and remember that a one stop change on the
| | 02:10 | guide number scale is based on a factor of
1.4, whereas a one-stop change on the ISO
| | 02:16 | scale is based on a factor of 2.
| | 02:19 | In actual practice, since I was born lazy, I do
my guide number math at my ISO at full power.
| | 02:26 | Then if I decide to adjust the power ratio
downward after I've begun shooting, I'll open
| | 02:31 | up my aperture or move my flash
closer to match the reduction in power.
| | 02:36 | In the next chapter, you'll see
these concepts in a live shoot setting.
| | 02:40 | I'll be making adjustments
and calling out details as I go.
| | 02:44 | Hopefully the shoot movies will strongly
illustrate the point that once you've got some practice,
| | 02:48 | determining flash exposure can
become almost second nature.
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|
|
3. Shoot Scenarios with StrobesApplying concepts: Shooting scenario setup| 00:00 | So, we're going into the warehouse, and
we've set up three different shoots inside a very
| | 00:04 | small space, and the first one that we're
going to take a look at is utilizing some
| | 00:08 | industrial ductwork that we've found in the
building, and we are going to illustrate using
| | 00:12 | some different colored lights on the
background to modify that background, and we're also
| | 00:17 | going to shake it up a little bit by shooting
with two different focal lengths on the camera
| | 00:22 | to give us a wide portrait and then something that's
a little bit tighter with a shallower depth of field.
| | 00:28 | So, here we go.
| | 00:29 | All right, so we've got this kind of high-tech
background that we set up and what we're going
| | 00:34 | to do here is put a red gel on one of the
background lights and a blue on the other.
| | 00:38 | And we're going to let them cross in the
middle and give us a nice magenta high-tech,
| | 00:42 | and then we'll put a neutral light on you, probably
somewhere maybe right around here to get started.
| | 00:49 | And then we're going to drop a couple of lights into these
tubes that kind of create some accents on the background.
| | 00:55 | We're going to start with hard lights, so
on modified, and when we're done with that
| | 01:01 | we'll leave the background lights in place,
move further away and get some tighter portrait
| | 01:06 | shots and kind of play around with the
depth of field to shake up the background focus.
| | 01:13 | So, you can take a break for 5 minutes,
we'll get the lights set and off we go.
| | 01:19 | So, I decided to shoot at f/5.6 for two reasons.
The first was to allow me to get the background
| | 01:25 | lights pretty far away from the set, because
I wanted to evenly illuminate the background,
| | 01:31 | and to do that, it's really
helpful if you get the lights far away.
| | 01:36 | And the other thing is I wanted to use a
relatively shallow depth of field on this initial shot.
| | 01:42 | So, 5.6 served two purposes.
| | 01:46 | Let's set a red light on this side,
blue on that, let's measure off.
| | 01:53 | We're going to shoot at 400.
So, let's set this light 18 feet away, right?
| | 01:59 | Lauren: Okay.
Brent: And then we're going to set at a quarter power.
| | 02:01 | Lauren: Got it.
| | 02:02 | Brent: Because I did the calculation, ISO 100, we are
shooting at 400, so we'll back it down to quarter.
| | 02:09 | So, I've got Lauren set up
18 feet away from my background.
| | 02:14 | A quarter power which would give me normal
exposure but what I've done is I had him put
| | 02:19 | a blue gel on that flash, and I need to compensate
for that so what I had them do is bump the
| | 02:25 | power up by stopping a third in order
to make up for the density of that gel.
| | 02:30 | So, I think I told you a quarter power,
so we need to compensate for that.
| | 02:35 | So, why don't you go to
minus two-thirds of a stop?
| | 02:40 | Lauren: Okay.
Brent: So, you'll go to half and then plus the third.
| | 02:44 | Lauren: Okay.
Brent: So that should get us a good start.
| | 02:46 | Lauren: Yeah.
| | 02:47 | Brent: I'm going to have Lauren kind of feather that
light or cheat it across the face of the background
| | 02:54 | so that it is aimed a little bit beyond
the midpoint, and that will help more evenly
| | 02:58 | distribute the light across
the width of the background.
| | 03:02 | So, I'm going with a red gel on the left-
hand side, and the reason that we're doing that
| | 03:08 | is to create kind of magenta
where those two lights cross.
| | 03:12 | So, we'll see red, we'll see blue, and we'll
see the complementary magenta color in the middle.
| | 03:18 | And again, I'm compensating on the red
gelled light just as we did on the other side but
| | 03:26 | this time I'm using a two stop conversion or
compensation because that gel is a little bit denser.
| | 03:31 | Okay, so we'll just walk through the math.
| | 03:35 | If we're at ISO 100, guide number is 90, I'm shooting at
5.6 so we said that put the flash, was it 16 feet away?
| | 03:44 | Lauren: 16, 18.
Brent: 18 feet away.
| | 03:48 | So we're going to start at 18.
| | 03:50 | I'm going to dial it down to a quarter
power because I'm shooting at 400, and then we're
| | 03:56 | going to take it back to full power because
of that filter, or the gel rather.
| | 04:00 | Lauren: Cool. Okay, we'll do that.
Brent: All right.
| | 04:03 | We also had these really cool elbows in
this set, and what I did was stuck a flash
| | 04:09 | in a couple of those and played off of the
yellow insulation that was in there.
| | 04:14 | So, I've got yellow highlights coming out
of these, and I just set the exposure for
| | 04:18 | those flashes by guessing at the beginning.
| | 04:20 | I ended up having to make some adjustments to
that, but I just went off of instinct on my
| | 04:25 | initial power settings on those.
| | 04:28 | I chose to put the lights at a pretty severe
angle to the background for a couple of reasons.
| | 04:34 | The first was to take advantage of the kind of
the depth that we created with those vertical tubes.
| | 04:41 | We offset them a little bit and by getting
that light pretty far off to the side we were
| | 04:46 | able to create some shadows.
| | 04:48 | The other thing that I wanted to do is to
really keep the light from spilling on to
| | 04:53 | the model, and I was--it's a little bit
easier to flag her off by virtue of having those
| | 04:57 | lights pretty far around to the back side.
| | 05:06 | So I think we're off to a good start if
we can keep that colored light off of her.
| | 05:11 | The very first shots that I did were with
the little accent lights in these elbow bends,
| | 05:18 | and so when I put those in place and
didn't have the other two lights going on,
| | 05:22 | I got a really nice saturated color coming off
from them, but by virtue of then adding the two
| | 05:28 | background lights that kind of got diluted,
so I needed to revise that a little bit.
| | 05:35 | After about 10 minutes' time, we got the background
lights set pretty much the way that we wanted them.
| | 05:41 | So, then it was time to start working
on the key light on the model herself.
| | 05:45 | All right, so if you can just hold your arms out like
that because I want to see how we did with two flags.
| | 05:53 | One of the things when you're using
multiple lights is really being aware of how those
| | 05:58 | lights interact with one another or
overlap, and oftentimes you don't want them to.
| | 06:05 | And certainly in this case, in the
initial set up we didn't want that.
| | 06:09 | So it's important to test before you get too
far along to see if indeed you are contaminating
| | 06:15 | your main subject with these two lights,
and indeed, even though we did have her flagged off,
| | 06:21 | we saw a little bit spilling on
to her body when she was in position.
| | 06:26 | So, the way that I corrected for that was
simply to have her take a step forward, and
| | 06:31 | that's all it took to fix the problem.
| | 06:33 | Why don't you come forward just one step,
hold the same, hurry out, there we go.
| | 06:39 | Okay so that's going to be your mark, so you
did a really nice job flagging those off because
| | 06:43 | we're not getting any real spill
off of either those two lights.
| | 06:47 | Lauren: Right.
| | 06:49 | Brent: So now what I want to do with the key is get
it pretty close to her so that the light fall-off
| | 06:54 | doesn't contaminate the background.
So, let's get that.
| | 06:59 | Let's start, I'm shooting at 5.6,
let's get that light maybe 8 feet from her.
| | 07:07 | The guide number on my key light is 90.
| | 07:10 | I decide to place the flash 8 feet from
the model, with a view towards minimizing the
| | 07:15 | amount of light that was going
to spill on to the background.
| | 07:18 | So, if I divide 8 feet into my guide number of 90,
that gives me a shooting aperture of f/11.
| | 07:26 | But remember, I'm shooting at 5.6, so I need
to cut the power of that strobe by two stops
| | 07:32 | from full power to half power to quarter power.
| | 07:36 | It's further complicated by the fact that
I'm shooting not at ISO 100 but at ISO 400.
| | 07:41 | So I need to reduce the power ratio two more
stops from quarter power to 8th power to 16th power.
| | 07:49 | So, we should be getting some nice accent
from that, the strobe that's in the can.
| | 07:54 | So, you can just relax.
We'll do a little test.
| | 07:58 | I took the first exposure at 8 feet, and I did
get a little bit of fill on the background,
| | 08:05 | it did indeed illuminate it, and I
want to minimize it as much as I can.
| | 08:09 | So, I decided to move the flash in a further
stop to f/5.6 which required that we cut the
| | 08:16 | power ratio from 16th power to 32nd power.
| | 08:20 | Okay, so Lauren, what I tried to do with that
move was to let this go a little bit darker again.
| | 08:27 | So I want to--we're going to increase the
exposure on her because that was a little
| | 08:31 | bit underexposed by virtue of it being up high,
even though the distance on the floor was right.
| | 08:37 | So that should, it's going to open her up a
little bit, and by moving it a little closer
| | 08:41 | that's going to knock that down.
| | 08:42 | Okay, so before we get started I will have
you look in the direction of the light just
| | 08:47 | to see how that looks and so
you can look over, there you go.
| | 08:52 | So, you can see we got an awful
lot done in about 12 or 15 minutes.
| | 08:57 | We did it without benefit of TTL, we
did it without using a strobe meter.
| | 09:02 | Simply by applying guide number math and
filter factors for the filters that we used or the
| | 09:08 | gels more properly, we were able to
achieve proper exposure very quickly.
| | 09:13 | In addition, we compensated for colored gels on those
background flashes, and we got proper exposure on our model.
| | 09:21 | Now, in the next movie you're going to see is modify
that key light to really get some wonderful images.
| | Collapse this transcript |
| Applying concepts: Scenario one| 00:01 | Okay, so now we're playing. Just keep that kind of a
distant look because I think that's really working.
| | 00:07 | So, in the last movie we established
exposure on the background and on our model.
| | 00:14 | I'm shooting at f/5.6, and that decision is
what drove my flash to subject distances and
| | 00:21 | my Power Ratio settings on the flash.
| | 00:24 | So I am happy with my exposure
on the subject at this point.
| | 00:27 | She is normally exposed, and I've
got nice colors on the background.
| | 00:31 | So, now we're going to modify the key light to
soften it and really start creating pictures.
| | 00:38 | Okay, the last thing we're going to do I
think on this setup is we'll pull the diffusion
| | 00:44 | flat in, and we're going to light her
softly through the diffusion flash, because
| | 00:49 | what I want to do is get her evenly
illuminated from top to bottom.
| | 00:53 | All right, I am going to kick the power of
those two background lights down even further
| | 00:59 | and then when we put the diffusion flat up,
we will have a little less contamination from
| | 01:05 | this light, so we're going to
knock this down another stop.
| | 01:08 | Lauren: One more stop. Okay.
| | 01:10 | Off camera here, it goes from 8 to 16.
Brent: Yep.
| | 01:13 | Lauren: That will be in the 11.
Brent: That's fine.
| | 01:16 | Lauren: Okay.
Brent: Yeah, on the Power Ratio, that's fine.
| | 01:19 | Lauren: Okay.
Brent: So that's a one stop.
| | 01:21 | Lauren: Got it.
| | 01:22 | Brent: The power ratios go one to one,
one-half, quarter, 8/16, 32.
| | 01:30 | Go back to probably a quarter.
Lauren: Okay,
| | 01:33 | Brent: In this series, let's really animate,
and you can give me lots of movement,
| | 01:38 | and I'll just--we're going to have to pause
three or four, five beats in between, but let's
| | 01:43 | get a whole big series.
| | 01:49 | So this is where you want to be able to
shoot fast because the model has only got so much
| | 01:53 | energy and being able to hit every
single one of these poses is really the idea.
| | 01:59 | Nice, so here's what the setup,
if you want to take a look.
| | 02:04 | So this is actually what was going on, so
we're getting fill, we've got the light, and
| | 02:09 | there is the end result, there are
some really nice shots in this series.
| | 02:14 | So Lauren, I think on this series of shots,
we want to start with the high key image,
| | 02:18 | I am going to blow out both Savannah and
the background by about a stop, and then I am
| | 02:24 | going to bring it back to
normal, simply by using ISO.
| | 02:27 | Lauren: Oh, good, okay.
| | 02:28 | Brent: And while we're doing that, if you want to
hit her with the fan, we'll get some hair move.
| | 02:33 | Lauren: Okay, cool, yeah.
| | 02:34 | Brent: After we've gone through that series, I'll
go back up to ISO 400, and we'll change the
| | 02:39 | exposure on the key light only, because what
I want to do is reduce the overall exposure
| | 02:44 | on her so that she stands out
against that kind of blown-out background.
| | 02:48 | Lauren: Okay, so, all right.
| | 02:51 | Brent: So, Savannah, we are ready. It's getting cold
in here so when we turn the fan on, it's going
| | 02:58 | to be really cold on her,
so we'll try to be quick.
| | 03:06 | For the set of images where I began by
deliberately overexposing her, what I did was I backed
| | 03:11 | up, I put a long lens on my camera, and I
asked her to come towards me with a view
| | 03:17 | towards shooting pretty wide-open
and softening the background.
| | 03:22 | So that's the change that we made
for round two in this set of images.
| | 03:27 | Okay, so you can see we've got blown
highlights in the background, we've got hot skin tones,
| | 03:35 | and it's a different look than what we've
gotten before, and I like it, but we're going
| | 03:39 | to start with this then we are going to go back
down to a normal exposure simply by adjusting our ISO.
| | 03:46 | So Lauren, if you want to get the fan going.
Lauren: Okay,
| | 03:49 | Brent: And then, Savannah, just play to
the camera and then a little bit to the light.
| | 04:00 | Maybe put your head down and
then kind of throw it back, sweet!
| | 04:04 | Just hang out for a second, I am going to
change the exposure, I am going to reduce
| | 04:08 | the ISO by a-third, fire off
another series, okay, nice!
| | 04:19 | Then turn your body towards the
diffusion flat and eyes at me, that worked, okay.
| | 04:27 | So I am going to go down another
third to 250, let's go without the fan.
| | 04:32 | Lauren: Okay.
| | 04:34 | Brent: Okay, nice. Okay, one more time.
Now I am going to reduce the ISO one more
| | 04:44 | time, and then we're going to make this
switch with the key light after a couple here.
| | 04:51 | And then give me that long far-away look.
| | 04:57 | So I decided to bracket my
exposures two different ways.
| | 05:01 | I did that simply by changing my ISO, and
it was only a one-stop bracket, and I did
| | 05:07 | that for illustrative purposes and
to get a little more visual variety.
| | 05:12 | And then the second bracket that I did was
by changing the Intensity or the Power Ratio
| | 05:17 | on the key light, so I kept the background
exposure the same throughout that series,
| | 05:22 | but I reduced the intensity of the light from
the key light by one stop, and that was simply
| | 05:28 | to get some visual variety.
So I am going to take the ISO back up to 400.
| | 05:33 | Lauren, why don't you drop that in third-stop
increments so we can illustrate what happens.
| | 05:39 | Lauren: Okay.
| | 05:40 | Brent: With the key light,
so it's one-eighth right now.
| | 05:43 | So, you're going to go to 1/8th minus 3.
Lauren: Okay.
| | 05:47 | Brent: Minus three-tenths, rather.
Lauren: Right.
| | 05:49 | Brent: And I am taking the ISO back up to 400.
Lauren: Okay.
| | 05:55 | Brent: Okay? Nice. Okay, let's knock that
key light down by another third.
| | 06:04 | So with this set of exposures, maybe you can
give me a couple of spins again.
| | 06:07 | Lauren: Minus 0.7?
| | 06:11 | Brent: Yep, nice. Okay, Lauren,
let's kick that light down.
| | 06:18 | Lauren: Okay.
| | 06:20 | Brent: Now the way that we have this
set up, we're getting a little bit of rim
| | 06:23 | light from both the background lights on her,
the cutter card, it's just keeping you off
| | 06:31 | the background, but it's spilling onto her,
so we're starting to see as we've knocked
| | 06:35 | that key light down a little bit of blue on.
Lauren: Oh I see.
| | 06:40 | Brent: On her front side, and a
little bit of red on her arms, so.
| | 06:44 | Lauren: So this is--
| | 06:45 | Brent: the reason that we're getting that
spill on her at this point that we didn't
| | 06:49 | get at the beginning is because I asked
her to move forward, and we didn't change the
| | 06:53 | position of those cutter cards, so the
light is now spilling onto her, but it's kind of
| | 06:59 | a cool effect that we've created by happy
accident, but what's important to note is
| | 07:05 | the effect that changes as the
intensity of the key light changes.
| | 07:09 | So as I knocked the key light down, you'll see
more of the blue and the red on either side of her.
| | 07:17 | So we're down a full stop from where we started.
Lauren: Right.
| | 07:23 | Brent: I'd say that's a wrap on this setup.
| | 07:26 | So the first shoot is all over. Now let's
take a look at some of the really wonderful
| | 07:30 | images that came out of this.
| | 07:32 | And when I first started shooting, I never
would have believed that results like this
| | 07:36 | would have been possible
without using TTL or a Strobe Meter.
| | 07:41 | But I've discovered over the course of my
career that guide number math and the knowledge
| | 07:46 | that comes from learning that really helps
problem solve, and what that allows me to
| | 07:52 | do is concentrate my energies on making good
pictures rather than just getting good exposures.
| | Collapse this transcript |
| Applying concepts: Scenario two| 00:00 | So, after we finished our second shoot, we
turned right around, and we had this very
| | 00:05 | cool old industrial baler that
was sitting there in the warehouse.
| | 00:09 | And so we decided to use this as a prop.
| | 00:12 | And it's relatively small, but it gave
us some interesting lighting challenges.
| | 00:16 | The inside of it was a shiny metallic finish,
and I wanted to kind of light that to give
| | 00:23 | a magenta glow around the model, and there
were some slats in the walls of it that we
| | 00:30 | decided to utilize by blowing smoke into the
scene, and backlighting it to create shafts
| | 00:36 | of light coming through this.
| | 00:37 | So, we had a little piece of equipment that we used I
think to great advantage as a background for our model.
| | 00:44 | So let's take a look at what we did.
We'll start with the light camera right.
| | 00:51 | Lauren: So, I'll take this around to put green
on it, or are you're going to put that front?
| | 00:57 | Brent: Yeah, you can put the green on it,
and then we'll just use this other.
| | 01:02 | We decided to utilize a green gel on one of the
strobes in the background and a magenta on the other.
| | 01:09 | The green gel was chosen to kind of play
off of the color of the baler itself and then
| | 01:16 | the magenta was a complementary color to that.
| | 01:19 | And the green worked well with the
peach dress that the model was wearing.
| | 01:24 | So, I think what we'll want to do, too, again
is flag off the light from that strobe from
| | 01:31 | killing what we're trying to do there.
Lauren: From back here?
| | 01:33 | Brent: Yeah.
Lauren: Okay.
| | 01:34 | Brent: Yep.
| | 01:41 | Well, that was a mistake.
| | 01:44 | Lauren: So, this is her mark, right at
the end of the tape here?
| | 01:48 | Brent: Yep.
| | 01:56 | Brent: I think I'll just lean this against there
to try to fill in the bottom too.
| | 02:01 | Lauren: Okay.
| | 02:05 | Brent: Let's start with this reflector, and
then we'll see what we get with that.
| | 02:12 | What's actually happening is it's getting a little
bit of light underneath, which is kind of nice too.
| | 02:29 | So, I placed the magenta gel light inside
the baler, and I placed it in there so that
| | 02:36 | I could kick reflected light off
for the two doors that are open.
| | 02:42 | Then we've got the green-gelled
flash behind the baler itself.
| | 02:47 | And when we blow smoke into that baler,
we see the shafts of light coming through
| | 02:52 | those little slats in the wall.
| | 02:54 | And, Savannah, what I want to try to do is use
your body to create some interesting shadows
| | 03:01 | on this wall, so we'll have
to play with that position.
| | 03:04 | And what that's going to require probably
is moving your right foot forward and turning
| | 03:09 | a little bit and giving some
gestures with your hand this way.
| | 03:13 | So, what I'd like to do is
create something cool there.
| | 03:19 | So maybe you could extend your right foot
just a little bit, more forward towards me.
| | 03:27 | Okay, let's see what happens with that.
Let's move that light in.
| | 03:32 | Lauren: The green one?
Brent: Yeah.
| | 03:35 | Lauren: Straight in?
Brent: Straight in.
| | 03:36 | What I'd like to do would be
to emphasize that a little more.
| | 03:39 | Lauren: To tilt it down.
Brent: Tilt it down.
| | 03:41 | I was unable to turn the head,
so you may have to--
| | 03:44 | Lauren: Put an apple box under.
Brent: Yeah, I want, yeah, to get that.
| | 03:50 | So, Savannah, here's what's going on.
| | 03:52 | So, this is what I want to try to
create, some interesting shadows there.
| | 03:57 | Savannah: Okay.
Brent: All right?
| | 04:01 | Lauren: Okay, I moved it in maybe 3 feet.
Brent: Okay.
| | 04:05 | Lauren: Tilted it down a little.
| | 04:06 | Brent: Good, and then the last thing is we
may have to move those two cutters again.
| | 04:12 | Okay, so as always, we use the guide number
math to find our starting point, and then
| | 04:18 | we kind of play it around with the fill
light or the magenta light in the back.
| | 04:26 | Okay, I think we're ready to roll.
We'll make some smoke.
| | 04:30 | Lauren: Smoke it up.
Brent: Are you seeing her feet now?
| | 04:35 | Yeah, we're going head to toe.
| | 04:40 | So, this time, if you can give me a lot of
volume with your body, that would be great, okay.
| | 04:51 | So, I'm going to crank up the ISO to 800.
| | 04:57 | I'm going to dial this back two stops, and Lauren,
maybe you can do the same on all three of those flashes.
| | 05:06 | So, we're going to go down two stops.
Lauren: Down two stops, okay.
| | 05:10 | Brent: I made the decision to increase the ISO
once again so that I could shoot faster.
| | 05:15 | By increasing the ISO, I'm able to reduce
the power ratios which allows me to recycle
| | 05:21 | the flashes faster so that the model can stay
more in a rhythm, and we get out the door faster.
| | 05:28 | So, it's as simple as that.
Nice, here we go.
| | 05:32 | Very good. Okay, I'm going to dial this
key down a third while you're doing that.
| | 05:40 | Okay, so we're going to do this quick, Savannah.
So, you can jump out Lauren.
| | 05:56 | What I'd like to do is put
that soft box on this key light.
| | 06:01 | We'll get in really tight.
| | 06:01 | I just want to see the effect of that,
and we'll figure out the guide number math.
| | 06:06 | So here's what we got.
This is really pretty trippy.
| | 06:11 | What I want to do is get that light with more
smoke on the back of your head, and then we're
| | 06:18 | going to shoot some silhouettes.
| | 06:20 | Then we're going to put the key light back on,
but we're going to make it really underexposed,
| | 06:25 | so there's just a little bit of
detail and hopefully a lot of mystery.
| | 06:29 | So, if you want to step back in, and I like
the way that you've held that out, there you go.
| | 06:41 | And then, Lauren, you may have to aim it up
just a little bit and then turn it a couple
| | 06:48 | of degrees to your clockwise.
And I think you're pretty good.
| | 06:55 | So the key is still off, right?
Lauren: Key is off.
| | 06:57 | Brent: Okay, and let's make more smoke.
| | 07:00 | So, Savannah, with your right hand, you can hold it
out pretty far, and with your left just a little bit.
| | 07:06 | There you go, yeah.
| | 07:08 | Now we're not going to see
your face, so this is just nice.
| | 07:14 | We introduced the fog into the scene to
create a little bit of mystery and drama.
| | 07:18 | And the way to really emphasize
that or play it up is to backlight it.
| | 07:23 | Now, if you light smoke, fog from the front,
you don't get nearly the same effect
| | 07:28 | as if you light it from behind.
| | 07:29 | And you can see the drama in these pictures that's
created by that snooted light blowing through the fog.
| | 07:35 | That's really nice.
I'm going to turn this guy on.
| | 07:39 | So, the notion is here just to
put a little bit of light on her.
| | 07:43 | And I'm not going to bother to do the guide
number math, I'm going to take an educated guess.
| | 07:48 | Lauren: So, more smoke?
Brent: So yeah, let's fire up smoke.
| | 07:51 | I think we're ready to go.
| | 07:53 | I'm intentionally showing the hair light,
because when it's coming through that smoke,
| | 07:58 | it really adds a nice bit of mystery.
| | 08:02 | Yes, very sweet, those are beautiful.
So, that's a wrap with this shot.
| | 08:10 | Okay, so what we're going to do here is
try to do something a little bit different.
| | 08:12 | I'm going to get that soft box up close to
evenly illuminate her face, and then I want
| | 08:19 | to try to get just a little bit another stop of light into
her eyes, and I'm going to shoot this with the Lensbaby.
| | 08:28 | What I'm doing here is
creating something different.
| | 08:31 | I've introduced a second light that
I am using to light the model's face.
| | 08:35 | We haven't done that before.
| | 08:36 | We've restricted ourself to the
key light only, a single key light.
| | 08:40 | Here, I'm going to do
something a little bit different.
| | 08:42 | I'm using a Lensbaby, which has a very narrow
point of focus, and what I want to do is focus
| | 08:50 | that lens on her eyes, but I also want to draw
our attention to her eyes by using the light.
| | 08:56 | So, I'm going to illuminate her more or less
evenly with the light from the soft box, and
| | 09:02 | I have a second light that has a snoot on it, and
I'm going to aim that light directly at her eyes.
| | 09:06 | So, we're going to see a narrow focus reinforced
by two things, the focus itself, and the amount
| | 09:13 | of light that's being put onto her eyes.
| | 09:16 | So let's start with--just for grins, let's
get this thing at 1/64th and shoot it 400.
| | 09:27 | Lauren: Okay, 1/64th and 1/28th.
| | 09:37 | Brent: Okay, and I'm going to shoot at f/5.6,
and I am going to get uncomfortably close, okay.
| | 09:48 | At this point, I've got that flash in tight,
and I know that I've got to really dial the
| | 09:54 | power down in order to pull this off.
| | 09:56 | So, it was just as quick for me now to start
out at 1/64th power as it would be to get the
| | 10:03 | tape measure out and do the guide number math.
| | 10:06 | Plus, I've put a soft box onto that flash
which kind of blows guide number math anyway.
| | 10:12 | So, I'm using my experience to get a starting
point, and then I'll go off of the histogram
| | 10:20 | if I need to refine it.
| | 10:21 | So, let's dial this down or let's
move it back just a tiniest bit.
| | 10:26 | Now, what I really want to
do is just get your eyes in.
| | 10:30 | Maybe we'll get some sparkle off of that dress.
I'm working now by process of iteration.
| | 10:37 | But you can see my starting point was really
close, and we got to the end result in just
| | 10:43 | a couple of moves, and this is where understanding
how guide number math works and the fundamentals
| | 10:49 | of light really pays big dividends.
| | 10:52 | Just by virtue of having that foundational
knowledge, if you do need to work by iteration,
| | 10:57 | you can get to the right
result much, much quicker.
| | 11:01 | Let's throw the last thing,
and then we'll call it a day.
| | 11:05 | Let's see if we can get this
magenta spread out a little bit.
| | 11:10 | So, a little bit of diffusion, you can probably
even bring one of the panels in or anything
| | 11:18 | that's going to kind of break that up.
Lauren: Okay, diffusion frame is in.
| | 11:24 | Brent: Okay, great. Okay, I'm
going to pull back a little bit.
| | 11:35 | The nice thing about working this closely
is the background, that white wall in the
| | 11:39 | back has gone completely black,
and we're able to shoot fast.
| | 11:46 | So, we've really got a nice effect I think
with the soft box illuminating an underexposure
| | 11:53 | and then using that snoot to key in and then
that point of focus is accentuated by the Lensbaby.
| | 12:03 | So, sometimes people who are shooting with
big soft boxes will put a hard light right
| | 12:08 | in the middle of the soft box, and right at
the subject to give it a little bit of a kick.
| | 12:14 | These are almost elfin-like
or wraith-like. Are you happy?
| | 12:19 | Savannah: Mm-hmm.
Brent: And we're done, that's a wrap.
| | 12:22 | Savannah: That's a wrap.
Brent: Okay, thanks!
| | 12:24 | Lauren: All right, thanks!
Brent: Thank you very much!
| | 12:26 | Savannah: Thank you.
Brent: Great, I appreciate it!
| | Collapse this transcript |
| Applying concepts: Scenario three| 00:01 | For our second shoot, we've just moved over
a little bit from the scene featuring the
| | 00:06 | industrial tubing to kind of an urban
outdoor setting that we've created, and what I have
| | 00:12 | in mind for this is to put some dramatic
lights into the room behind the model and then also
| | 00:19 | then light her with a normal exposure and try to
emulate a street light coming down from overhead.
| | 00:27 | So the objective is again to get a normal
exposure on the model, create some drama in
| | 00:32 | the background and then ideally create kind
of a little bit of an accent light with this
| | 00:39 | overhead street lamp. So here we go.
Okay, Savannah, you can just hang out on that mark.
| | 00:44 | I'm just going to take an exposure to
see what the overall lighting looks like.
| | 00:50 | The light on you is perfect, but we've got a
big hotspot on the left-hand side of the frame.
| | 00:57 | So, Lauren, I still want to shoot at f/8,
because she is going to be moving through
| | 01:00 | that frame so I need the depth of field.
| | 01:03 | So when I had the flash 11 feet from the model,
I got this pretty bright hotspot in the upper
| | 01:08 | left-hand corner, and I wanted to try to
eliminate that, and one thing that I could have done
| | 01:13 | would have been to place a screen or some
netting, diffusion material between the flash
| | 01:19 | in that hotspot to kick that value back down, but
they didn't have any on the set that would work.
| | 01:25 | All the diffusion flats that I had had hard
edges that would have cast a noticeable shadow.
| | 01:32 | So the next place I went with this was to
move the flash back from 11 feet to 22 which
| | 01:38 | will help me more evenly illuminate the background
from the right-hand side to the left-hand side.
| | 01:44 | Then I've asked Lauren to cheat or feather
the flash, aim it beyond the center point
| | 01:51 | so that the fall-off from the flash
occurred on the left side of the frame.
| | 01:57 | By doing those two things, moving the flash
back and feathering it past the center point,
| | 02:01 | I was able to more evenly illuminate the background,
and I did that while maintaining normal exposure
| | 02:08 | on the model by opening
up the lens to compensate.
| | 02:11 | We made a two-stop change
by doubling the distance.
| | 02:14 | So we should be good to go.
All right, big smile.
| | 02:18 | All right, we're getting close.
| | 02:22 | So the problem we're dealing with is that
the flash to subject distance on the left-hand
| | 02:26 | side of the wall is quite a bit
closer than it is on the right-hand side.
| | 02:29 | So what we need to do is just keep cheating
that light up, but the light on her is perfect.
| | 02:37 | Now what we're going to do, Lauren, is
get this light going on the backroom here.
| | 02:40 | Lauren: All right.
| | 02:42 | Brent: So, I've set these grates up,
because I want to throw a pattern across this
| | 02:47 | wall to give it a little more visual variety,
and what I also want to do is underexpose
| | 02:53 | the wall by a couple of stops.
| | 02:56 | So I was in here earlier, and I measured 16 feet
from where we have the flash to the wall,
| | 03:03 | but I did that calculation when I
thought we were shooting at ISO 100.
| | 03:09 | So what we need to do is dial that flash down
from full power to quarter.
| | 03:12 | Lauren: I see, okay.
| | 03:13 | Brent: And we're going to use a green gel,
because I don't really like the pink.
| | 03:18 | The way that I've set this scene up is that I'm
lighting each one of these elements independently.
| | 03:23 | So the background in this
case is just like the subject.
| | 03:27 | So I'm doing my guide number math as if I
were lighting the subject, because the background
| | 03:32 | is being illuminated just by this one flash.
| | 03:35 | As long as my lights don't cross one
another, I can do that, and I should do that.
| | 03:41 | So I treat the background just like a
subject when I do my flash to subject calculations.
| | 03:46 | All right, that's pretty cool.
We've nailed that background exposure.
| | 03:50 | So we got this really long shadows raking across
the back wall. It's green. It's urban.
| | 03:57 | Now the next thing we're going to do in
that room is turn this other flash on.
| | 04:03 | We've placed it high against the ceiling,
and I want to throw a light through this window
| | 04:09 | onto the ground in front of her feet, and we're
pretty close to matching the color on the wall.
| | 04:14 | So we need to dial this one
down to a quarter power as well.
| | 04:24 | So what that light is going to do is rake some
green light coming through that grating across her feet.
| | 04:30 | It will give a little bit more dimension in the right-hand
window, adding a spotted color to that as well.
| | 04:37 | So it's working well with the yellow graffiti.
All right, so we've hit the floor with that light.
| | 04:52 | Let's dial it up to half power.
It's coming through nicely.
| | 04:55 | I'd like to bring it up just a little bit.
Yeah, that's nice.
| | 05:04 | We're good. Okay, So let me just show you, Savannah,
what we got going on here. That's the scene.
| | 05:18 | Savannah: Cool.
| | 05:22 | Brent: So we'll up pull in a little bit tighter when
we end up shooting, but that's where we're starting.
| | 05:27 | Then the last thing we're going to do is put
a light on it from overhead to make it look
| | 05:31 | like you're under a street
light lamp outside. Okay?
| | 05:34 | So we're there just testing that one.
| | 05:38 | Lauren: Want me to get that?
Brent: Yep.
| | 05:41 | So again, that one's got to
come down to quarter power.
| | 05:46 | Lauren: Quarter power. Okay, Brent,
quarter power with orange gel on it.
| | 05:53 | Brent: Yep. So what we're trying to get from the overhead
light is the feeling of a sodium vapor light,
| | 05:58 | and it's going to cast a little bit of light at
her feet and give maybe a tiny bit of hair light too.
| | 06:07 | What's the zoom head setting on that?
Lauren: Zoom is 80.
| | 06:11 | Brent: Okay, let's go to a 105 and then
knock the power back to 1/8th power.
| | 06:17 | We initially had the overhead light that
was going to emulate the street lamp set
| | 06:22 | at a zoom head of 80 millimeters, and that
cast a beam that was barely noticeable on
| | 06:30 | the test shot, but it cast a beam that
was a little bit broader than what I wanted.
| | 06:34 | So what I asked him to do was to increase
the zoom head setting to 105 millimeters to
| | 06:41 | narrow that down and after he did that I
asked him to reduce the power setting by one stop
| | 06:47 | to compensate for that more
concentrated beam of light.
| | 06:53 | I really didn't get the full effect of
that overhead light that I was hoping for and
| | 06:57 | the reason for that was that I've created a
normal exposure on the model and on the wall.
| | 07:03 | So the additive effect of that
overhead light is pretty small.
| | 07:09 | What I could do would be to go in in post-
production and kind of modify that and fix it,
| | 07:14 | but it really didn't work
quite the way that I'd hoped for.
| | 07:18 | Had I put a snoot on that key light on the
left-hand side and funnel that light directly
| | 07:25 | onto her and minimize the spill onto the background
wall, then I would have seen what I was looking for.
| | 07:32 | But this setup just didn't quite
work the way that I anticipated.
| | 07:35 | So, Savannah, we're going to do maybe a dozen
takes on this just hit that mark, you'll see
| | 07:40 | the flash go off, go another stride.
Then we'll just start over.
| | 07:45 | So you can look in a
different direction each time.
| | 07:48 | Occasionally, give me a little bit of volume
with your skirt and just do what you're good at.
| | 07:54 | Then we'll just go slow, because I want to
make sure that all the flashes recycle each time.
| | 08:00 | So there's no rush.
All right, good.
| | 08:15 | Keep coming.
Great.
| | 08:17 | So, even though I didn't get the full
effect of that overhead light, there is a little
| | 08:21 | bit of a rim light and a hair
light showing up on the model.
| | 08:25 | So it did give me a little bit of
added value for having that light up there.
| | 08:31 | This time, Lauren, let's make a small change.
| | 08:33 | When she's got that skirt coming out, I'd
like to be able to blow that light through
| | 08:38 | it as well, because it's disappearing, so
maybe we can cheat it over so that we still
| | 08:43 | get some spill coming
through this window, but also here.
| | 08:48 | Lauren: Here, before she goes through?
Brent: Yeah.
| | 08:51 | Lauren: Okay.
Brent: All right, fire it up. Good deal.
| | 08:59 | Lauren, let's turn that smoke
on and see what happens here.
| | 09:05 | So let's really fill that room up,
and then we'll see what--
| | 09:08 | Lauren: Fill it up?
Brent: Yeah.
| | 09:10 | I'll shoot as we go.
All right, that's good, Lauren.
| | 09:20 | Okay, do that again as
soon as that flash recycles.
| | 09:26 | So let's give it 10 seconds.
| | 09:29 | So this is another reason to shoot at a higher
ISO, because it allows us to use a lower power
| | 09:34 | ratio, which will save batteries.
So we'll swap those out when we're done.
| | 09:39 | So I really liked what you did.
Yeah, that's nice. We're good.
| | 09:48 | Savannah, this time we're going to do a
tighter kind of head and shoulder shot and then maybe
| | 09:53 | a little bit looser, but we're going to
narrow down on the background for sure.
| | 09:57 | The way we're going to illustrate this
is by turning one light on at a time.
| | 10:01 | So I've got same green gel on a C-stand over
your left shoulder, and that's going to produce
| | 10:08 | a little bit of a rim light.
So I'm going to take that shot now.
| | 10:11 | So you can just hang out.
| | 10:13 | There is this very subtle
light on her left side.
| | 10:18 | Then, Lauren, if you could
turn that hair light on.
| | 10:22 | Lauren: Okay.
Brent: Thank you.
| | 10:24 | So, now we've got a nice little hair
light with a bit of spill on her shoulder.
| | 10:30 | I'm going to run in and
turn the background light on.
| | 10:33 | I've changed the gel to a blue
gel, a very deep, dark blue gel.
| | 10:41 | I want to get a, oh, 2 & 1/4
or 2 & 1/3stop under-exposed backdrop,
| | 10:47 | and we should just get a nice blue
rich backdrop going here. That fired.
| | 10:56 | I'm going to turn on the key light. Nice.
| | 11:07 | Okay, we're in business.
So I'm going to move in.
| | 11:11 | I am going to shoot vertically.
We've got all the lights.
| | 11:13 | We nailed the key light exposure.
We did the guide number math.
| | 11:18 | Guide number 90 divided by 6 feet gave up f/16.
I didn't want to shoot at f/16.
| | 11:27 | I want to shoot pretty wide open at 4.
| | 11:32 | So, what we did is we dialed that key light back to
1/16th power, and that allowed me to open up to f/4.
| | 11:45 | Beautiful. That's great.
I'm shooting too fast.
| | 11:53 | So what I want to do now is increase the ISO
by three stops, that's going to allow us to
| | 12:01 | dial the strobes down by three stops as well.
In the case of the key light we're going to
| | 12:07 | go from 1/16th power to 1/28th.
| | 12:11 | In the meantime, I'm going to increase the
ISO from 100 to 800, and then we'll have to
| | 12:18 | make the changes on our
background lights as well.
| | 12:22 | What this is going to allow me to do is just
shoot really a lot faster, which is going allow
| | 12:29 | Savannah to be a little more energetic and
playful without breaking rhythm. So we'll get that.
| | 12:38 | Now we're just going to shoot pretty quick.
So I'm going to move around a little bit.
| | 12:43 | I going to get it off the tripod,
and we'll just have some fun.
| | 12:50 | So I increased the ISO to
allow me to shoot faster.
| | 12:53 | By increasing the ISO, I could dial the
power down on the strobes, which saves batteries
| | 12:58 | which saves recycle time which allows
me to shoot at a much faster pace. Nice.
| | 13:07 | All the flashes are firing right on time.
| | 13:09 | Let's shake this up a little bit
and soften that key light now Lauren.
| | 13:14 | While we're shooting these if you
could just look and move across the clock.
| | 13:19 | So if you can look a little bit
towards the light and then come back to me.
| | 13:24 | Start at the light.
Okay, eyes at me.
| | 13:29 | Great. We got beautiful exposures.
| | 13:33 | The shadows are a little tough
because it's on modified light.
| | 13:39 | It's going to work for some of these shots.
| | 13:41 | But, Lauren, let's bring in
that diffusion reflector.
| | 13:47 | So what we're going to do is just fill in the
shadows very passively without using another
| | 13:54 | light and without changing the
exposure on the key side of the face.
| | 14:02 | Let's get it right in tight.
Lauren: Okay.
| | 14:05 | Brent: Okay, great. Nice.
Now, if you can go back that way with your head.
| | 14:20 | We got those fluorescent lights in
the background which is really cool.
| | 14:23 | We are keying off of the fluorescent tube.
Lauren, let's put an umbrella on that guy.
| | 14:40 | So by shooting at f/4 at such a high ISO, I'm
getting a little bit of light from the bulbs
| | 14:48 | on the inside which is illuminating one of
the building posts which really looks good.
| | 14:54 | That green against the blue.
| | 14:56 | So it's a nice little mix of ambient and strobe.
Now, let's see here. Great.
| | 15:12 | Let's bring that light around, and now that
we've diffused it, let's drop it just a little bit.
| | 15:20 | Okay, and the thing that I failed to tell
you to do was to compensate for the umbrella.
| | 15:26 | So let's bring it in a stop and a third.
| | 15:30 | So we're going to go from 6 feet
to 5.6 to 5 to 4.5 to 4 feet.
| | 15:40 | Lauren: 4 feet.
| | 15:42 | Brent: Yeah. I should have checked. Nice.
All right, those exposures are much, much better.
| | 15:54 | So let's use this to our advantage, and if
you want to step behind that, I will just
| | 15:59 | swing this around a little bit.
| | 16:06 | Let's see what we get with that.
Now step in between them.
| | 16:24 | Let's kill the overhead light, and then
we'll take a few more, and then we'll be done.
| | 16:28 | Lauren: All right, The reason that I killed
the overhead light was that when I asked her
| | 16:32 | to step back into that, it was beginning to spill
a little bit too much onto her forehead and nose.
| | 16:37 | So I wanted to get rid of that and really just get
a soft light on her. That's beautiful. Thank you.
| | 16:47 | All right, that's a wrap.
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