Join Joseph "PhotoJoseph" Linaschke for an in-depth discussion in this video Aperture priority, part of Photography 101.
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- Aperture priority is my personal favorite mode. That's the mode that I shoot in probably 90% of the time. What is aperture priority? Basically what it means is that you, as the photographer, are going to choose the aperture, and the camera is going to choose the shutter speed. Now before we get into how that works and what that means, let's first take a look at how to get in aperture priority mode. So on this camera, on the Lumix, you'll notice at the top that we see four letters, P, A, S, and M. P as for program, A is for aperture priority, and then shutter priority, and manual. Of course, aperture priority is what we're looking at here.
If we look at the Sony, you'll see the same thing, there's P for program, A for aperture, and then shutter, and manual. On the Canon it's a little bit different. You have P for program, and then TV for time valuation, that's your shutter speed mode. It's called time valuation on the Canon. A for aperture valuations, there's your aperture priority, and of course, manual after that. On the Fuji it's different yet again. You'll notice here on the Fuji that there is no P, A, S, M mode on top of the camera.
You have your shutter dial and you have your aperture rate. Both of these are currently set to A. That basically means fully automatic or programmed. If I want to put this into aperture priority, I simply spin the aperture ring, and now that I can control the aperture, while the shutter speed is still set in automatic, I'm now in aperture priority. I'm choosing the aperture, the camera is going to choose the shutter speed. Your camera may be a little bit different than what you see here, but basically every DSLR or mirrorless camera is going to have an aperture priority mode. OK, so now that we know how to get into that mode, what is it doing? So, again, in aperture priority mode, you as the photographer choose the aperture, the camera chooses the shutter speed.
So what is the aperture? Well, the aperture is a ring that is inside the lens that opens and closes, that controls the amount of light coming through. Let me show you exactly what this means. On this lens here you can see the aperture is wide open. And as I spin the aperture dial, the aperture ring closes down, letting less and less light through. Open it back up, and it lets more light through again. That's the aperture ring. So if it's closing down and letting more or less light through, then what else is happening? Well, if you imagine an exposure is like a bucket of water, that bucket of water has to be filled.
Now it can be filled quickly or it can be filled slowly, either way, it's got to be filled. The aperture controls how much light is coming through the lens. If the aperture is very small, less light is coming through the lens, and so it's going to take longer to fill that bucket. Which means the shutter speed has to be longer. You have to have the shutter open for a long period of time so that you can fill the exposure, or fill the image, with light. If you open it up all the way, so that it's letting a lot of light through, that bucket's going to fill up faster. So the difference is if you had a narrow garden hose trying to fill a bucket, or a big fire hose trying to fill a bucket.
That narrow hose is going to take longer to fill the bucket than the big fire hose would. That's essentially all aperture does, it controls the amount of light that's coming through the lens. Now this also has another effect. The effect that it has is something called depth of field. If you have a very wide aperture, a very large opening, you have a very shallow depth of field. If you have a very narrow aperture, a very small opening, you're going to get a larger depth of field. OK, what's depth of field? Well, depth of field is how much is in focus at once. So imagine, if you will, we're shooting this direction and I have a subject here and another subject over here.
If I have a very shallow depth of field, one subject is going to be in focus, while the one behind them, and even the one in front of them are soft. If I have a really large depth of field, then I might get all of them in focus at once. So if you've seen a photo of, for example, a person, where the person is sharp but the background is soft, that's a shallow depth of field. You'll also hear that soft background referred to as bokeh, or boe-kay, depending on who you ask. That shallowness of field is usually very attractive for things like portraits, but if you're shooting a landscape and you want to have the trees in the foreground, the mountains in the background all in focus at once, then you need that larger depth of field, which is the smaller aperture.
OK, so now let's talk about numbers. If I pick up this Fuji camera, you'll see on the aperture ring it goes from 1.4 up to 16. Now 1.4 is the largest aperture. Now it's the smallest number, I know that seems odd, but I'll explain this in a moment. 1.4 is the largest aperture, letting in the most amount of light. On this lens, F 16 is the smallest aperture, letting in the least amount of light. That smallest aperture, the 16, is going to give the largest amount of depth of field, the largest amount of stuff in focus at once. The larger aperture, F 1.4, lets in more light but gives you a narrower depth of field.
How are you supposed to remember this? And why are the numbers backwards? Well, that 1.4 is actually a fraction. It's F over 1.4. When you see the F-stop written as F, slash, and then a number, that's your aperture, and that's what this is. F is for focal light, and that's a whole other discussion we don't need to get into. All you need to remember is that the smaller number means the smaller amount of stuff in focus. A bigger number means a bigger amount of stuff in focus. That's the easiest way to remember it. So if you want that really shallow depth of field for the portrait, make the number on the aperture as small as it can go.
On this lens that's 1.4. Your lens might be 2.8 or even F four. You might have a lens that goes down to 1.2. Or this one here goes all the way down to 0.95. It gives me incredibly shallow depth of field. It just depends on the lens, but that smaller number is going to give you less depth of field, which is what you usually want for those images like portraits. The bigger number, more depth of field, which is what you want for scenery.
- Adjusting aperture, shutter speed, and ISO
- Controlling autofocus
- Using buttons to change focus, metering, and shooting modes
- Carrying a camera like a pro
- Stabilizing the camera
- Working with flash
- Thinking creatively and changing your point of view
- Buying new gear