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Working with masks and calculations in Photoshop


The Practicing Photographer

with Ben Long

Video: Working with masks and calculations in Photoshop

In the days of the Dark Room. It sounds like we're talking about, you know, the 19th century or something, which I guess we were. But, it went well into the 20th century. Anyway, back when people worked in Dark Rooms, they had to spend a lot of time developing dodging and burning skills. This was a kind of critical eye-hand coordination that they had to get to be able to make selective edits. Hi, I'm Ben Long, and this week on The Practising Photographer we're going to look at some Digital Masking skills. The equivalent of dodging and burning in the dark room era. And just as important now because even with the great cameras we have.
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  1. 20m 3s
    1. Pulling stills from a timelapse NEW
      6m 8s
    2. 1m 35s
      1. Introducing The Practicing Photographer
        1m 35s
    3. 12h 10m
      1. Choosing a camera
        5m 27s
      2. Looking at light as a subject
        2m 22s
      3. Using a small reflector to add fill light
        5m 45s
      4. Editing photo metadata with PhotosInfo Pro for iPad
        6m 30s
      5. Let your lens reshape you
        7m 26s
      6. Compositing street photography images with Photoshop
        7m 44s
      7. Expand your filter options with step-up and step-down rings
        3m 56s
      8. Shooting without a memory card
        3m 6s
      9. Give yourself a year-long assignment
        5m 28s
      10. Working with reflections
        1m 26s
      11. Exploring mirrorless cameras
        7m 25s
      12. Batch processing photos with the Adobe Image Processor
        7m 30s
      13. Limiting yourself to a fixed-focal-length lens
        2m 13s
      14. Creating tiny worlds: Shooting technique
        4m 15s
      15. Creating tiny worlds: Post-processing techniques
        11m 41s
      16. Shooting macro shots on an iPhone
        3m 18s
      17. Using a tripod
        3m 33s
      18. Wildlife and staying present
        5m 58s
      19. Batch exposure adjustments on raw files
        6m 52s
      20. Why Shoot Polaroid
        11m 12s
      21. Seizing an opportunity
        4m 4s
      22. Four photographers do a light-as-subject exercise
        12m 24s
      23. Shooting macro bug photos with a reversed lens
        4m 54s
      24. Varnishing a photo for a painterly effect
        13m 36s
      25. Shooting wildlife
        7m 24s
      26. Discussion on how to shoot architecture
        12m 27s
      27. Using a lens hood
        4m 48s
      28. Working with themes
        2m 48s
      29. Setting up an HDR time lapse
        7m 55s
      30. Processing an HDR time lapse
        7m 55s
      31. Two perspectives on travel photography
        12m 28s
      32. Scanning Photos
        5m 37s
      33. Photo assignment: shooting an egg
        3m 13s
      34. Reviewing the egg shot images
        6m 47s
      35. Shooting in your own backyard
        4m 38s
      36. Jpeg iPad import process
        3m 17s
      37. Shooting a product shot in open shade
        9m 34s
      38. Reviewing the product shot images
        4m 5s
      39. Warming up
        3m 26s
      40. Taking a panning action shot
        10m 17s
      41. Scanning polaroid negatives and processing in Photoshop
        8m 17s
      42. Shooting a silhouette
        3m 9s
      43. Going with an ultra-light gear configuration
        5m 29s
      44. Working with masks and calculations in Photoshop
        12m 38s
      45. Working with flash for macro photography
        4m 56s
      46. Colorizing a black and white photo in Photoshop
        5m 10s
      47. Using duct tape and zip ties in the field
        4m 14s
      48. When the on camera flash is casting a shadow
        3m 4s
      49. Using Lightroom on the road
        6m 28s
      50. Listening to your camera to get good exposure
        2m 20s
      51. Shooting a successful self portrait with a phone
        7m 18s
      52. Switching to Lightroom from another application
        9m 48s
      53. Photographing animals in wildlife refuges
        6m 41s
      54. Shooting level
        2m 42s
      55. Photoshop and Automator
        8m 54s
      56. Shooting when the light is flat
        3m 23s
      57. Discussing the business of stock photography
        9m 48s
      58. Shooting tethered to a monitor
        3m 21s
      59. Making a 360 degree panorama on the iPhone
        4m 45s
      60. Understanding the three flash setup
        3m 34s
      61. Shooting a three flash portrait
        4m 6s
      62. Understanding the differences with third party lenses
        4m 43s
      63. Understanding why files look different on depending on device
        5m 25s
      64. Working with a geotagging app on the iPhone
        4m 43s
      65. Using high speed flash sync to dim ambient light
        7m 29s
      66. Using your iPad as a second monitor
        5m 46s
      67. Understanding exposure with a leaf shutter camera
        3m 28s
      68. Photography practice through mimicry
        8m 8s
      69. Canon wireless flash with built in radio control
        5m 59s
      70. Posing and shooting pairs of people
        5m 35s
      71. Shooting with a shape in mind
        3m 15s
      72. Shooting tethered to a laptop
        4m 40s
      73. Softboxes vs. umbrellas
        2m 55s
      74. Getting your project out into the world
        6m 25s
      75. Exploring how to think about shooting a new environment
        3m 56s
      76. Discussing the book "The Passionate Photographer" with Steve Simon
        6m 4s
      77. Highlighting iOS 8 updates on the iPhone5S
        10m 46s
      78. Exploring manual controls with iOS 8 and ProCamera
        5m 30s
      79. Understanding how to compose with an empty sky
        4m 54s
      80. Using an iPhone to make a print in the darkroom
        7m 16s
      81. How to use glycerin as a photography tool
        2m 16s
      82. Understanding micro focus adjustment and Lens Align
        11m 19s
      83. Working with hair in post
        3m 28s
      84. Taking a quick portrait and directing a subject
        5m 50s
      85. Getting inspired through the work of others
        11m 22s
      86. Taking a flattering portrait with flash
        4m 21s
      87. Creating an unaligned HDR image
        3m 3s
      88. Exploring how to use Bokeh
        5m 38s
      89. Shooting stills from a drone
        6m 57s
      90. Using a monitor to get a first person view of the aerial camera
        8m 0s
      91. Understanding lens profile correction
        5m 33s
      92. Working with models
        2m 40s
      93. Understanding the labels on SD cards
        10m 32s
      94. Setting up a macro time lapse of a flower
        6m 18s
      95. Taking a portrait that's tightly cropped or slightly obscured
        3m 24s
      96. Tips for shooting panoramas
        7m 16s
      97. Carrying a point-and-shoot camera
        4m 44s
      98. Adjusting the color of shadows in an image
        5m 35s
      99. Evaluating camera-strap options
        4m 42s
      100. The 100th Practicing Photographer
        3m 31s
      101. Using light-pollution maps for planning night shoots
        3m 26s
      102. Shooting a series of star shots for a stack
        8m 32s
      103. Stitching together stacks of stars
        8m 59s
      104. Understanding how to clean sensor dust
        10m 27s
      105. Dry sensor cleaning
        6m 23s
      106. Cleaning the sensor with moisture
        7m 32s
      107. Composing in the center
        2m 48s
      108. Working with an electronic shutter control
        2m 50s
      109. Understanding how to use the Wi-Fi feature in some cameras
        2m 56s
      110. Exploring the software equivalent to graduated ND (neutral density) filters
        7m 8s
      111. Don't be predictable in your framing
        10m 21s
      112. Shooting with ND filter and flash to balance subject and background exposure
        2m 42s
      113. Understanding when to go low contrast
        3m 15s
      114. Reasons for shooting images alone
        4m 5s
      115. Working with colored lens filters and converting to black and white
        14m 4s
      116. Waiting for a subject when the light is good
        5m 2s
      117. Understanding options for tripod heads
        7m 23s
      118. Shooting a slow-shutter zoom-and-spin shot for light effect
        4m 47s
      119. Shooting and processing a long exposure at night
        10m 0s
      120. Getting creative with image curation
        4m 12s
      121. Why equivalent lenses don't always meter the same
        5m 42s

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Watch the Online Video Course The Practicing Photographer
12h 32m Appropriate for all May 16, 2013 Updated Aug 27, 2015

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In The Practicing Photographer, photographer and teacher Ben Long shares a weekly serving of photographic instruction and inspiration. Each installment focuses on a photographic shooting scenario, a piece of gear, or a software technique. Each installment concludes with a call to action designed to inspire you to pick up your camera (or your mouse or smartphone) to try the technique for yourself.

Ben Long

Working with masks and calculations in Photoshop

In the days of the Dark Room. It sounds like we're talking about, you know, the 19th century or something, which I guess we were. But, it went well into the 20th century. Anyway, back when people worked in Dark Rooms, they had to spend a lot of time developing dodging and burning skills. This was a kind of critical eye-hand coordination that they had to get to be able to make selective edits. Hi, I'm Ben Long, and this week on The Practising Photographer we're going to look at some Digital Masking skills. The equivalent of dodging and burning in the dark room era. And just as important now because even with the great cameras we have.

And the fantastic post-production that we have still, what can save an image sometimes is the ability to make a selective edit, to lighten or darken just one part of the image or the other. In a case like this, where I went to edit this camel, separately from the background, I ran into a problem because this camel is all furry. The edges of it, has a little hair and things and if you've ever tried to mask around that. You know that it can be very difficult. It was much harder in the Dark Room when you had to do that with dodging and burning, this a capability that we have in the Digital era that didn't exist before. Never the less, it can still be tricky unless you've got some of the tools that Photoshop introduced around CS 5 or so, the Refined Edge Command, and I want to show you that really quickly.

And then go into something that, I don't see a lot of people doing. Which is using the calculate Dialog Box to build complex masks that really allow you to gain a lot of control over your selective editing. So what I want to do is darken the background. The camel is up against this bright sky. Tonally the camel and the background are not that different. I think I can make an image that has a little more depth to it, a little more drama if I darken the background separately, I'm taking the quick select tool here. Which is a combination of a magic wand and a paintbrush. And I'm adjusting my brush size with the left and right bracket keys.

And I'm just painting over the camel. And as I paint, it does this kind of little localized magic wand thing, and it's starting to select the Camel. I find with the Quick Select tool it's best to make small strokes and then stop, rather than try to paint the camel all in one stroke. Invariably when you do that it goes and grabs other things in the image. So I'm just making short strokes here, and letting it figure out the rest. I'm not worried about these strokes creating a perfect mask. I'm going to go in and improve the mask in a, in a little bit. I just need a rough selection of this camel here.

This of course is a Bactrian camel, I know that because it has two humps rather than one. The one humped camel would be the Dromedary camel and as I'm sure you know the Bactrian camel is native to central Asia; the Russian Step rather than the, yes this is the camel education section of the video here. I just need something to talk about while I was painting, I knew it was going to take a while. So incase you are wondering do I really just sit around and learn about camels? No I just looked all that up on the Wikipedia I shot this is southern Siberia a couple of months ago.

Alright I mostly got this where I want it. There are a couple of things that need to be picked up here that I'm not going to worry about except for this little bit of his tail. There's probably something important to say about the tail of a Bactrian camel but I don't know what that is. So there we go. You can see that I've got generally the camel selected. I don't have stuff selected up here on the humps. I don't have really any of his fur selected. I can actually do a little bit better job there. Something that happened earlier that, I didn't call out cause I was too busy telling you about Bactrian camels.

I accidentally selected this part, so I don't want this area between his front legs, if I hold down the Option key, I get the ability to remove things from a selection and I do that just by painting over them. So I'm just using the Quick Select tool in combination with the option Quick Select tool or Alt if you are on a PC to select thing, things. So, now I have got a pretty good camera mask there, except it's going to look lousy around all this hair stuff. I am going to the Select menu and choosing Refine Edge. This is going to let me really improve the edges of this mask.

First thing it does that it drops out the background or it drops out everything on the outside of the selection it just shows me white. I can change what I want in the background. I'm just going to stick with white, that's fine here. The key to this particular problem lies right here in the Edge Detection part of this Dialog Box. I'm going to check Smart Radius and dial my radius up here to about one, maybe a little less, maybe a little more. I'm never that picky about it. And I'm going to grab this paintbrush right here. Now, all I have to do is paint along the troublesome parts of the edge here, like this furry bit right here.

I'm just going to paint along the boundary there and when I let go of this brush, Photoshop's going to think it over and reassess it's idea of where the edge is. So, basically, what I'm doing with this brush is just giving Photoshop some hints. I'm saying, oh mighty Photoshop right here is an edge, could you go back and do a little bit more calculation on that and it does and the calculation is good enough that it can put in these difficult bits. Soft edge fur, and it does a spectacularly good job.

One thing about this kind of mask particularly on a background like this I, I have a great advantage that my background. Is very totally similar to my foreground is, even if this mask isn't perfect, even if I don't have every tiny little bit of wispy hair, it's not going to show. Because a lot of the troubles in the mascot is going to blend into the background. And all I need is just enough of the wispy hair to indicate or to it imply a furry edge, I'm going to be fine. I could go and paint around the entire thing I don't think I'm going to have to because a I, I really only need to get the parts with fur these bits here where the fur is more matted down are going to look okay.

Now, of course, if I was masking a Dromedary camel it wouldn't take as long, because as you know, there would only be one hump, but this being a Bactrian camel I do have to do both, and the other real problem in here is going to be the tail. It was the area that was really full of a lot of separation of individual, individual hairs and things. And as I'm painting Photoshop reveals the areas that, areas that I had not even selected. So this tool is very forgiving in that way. I don't have to have my initial selection dead on.

You can also see that I'm painting pretty sloppily here. And it's still working out okay. If I end up painting in more detail then I like. I actually have the ability to pop this open and change to erase refinement. That would allow me to restore the edge to where it was originally. I think this is really good. I think it's all chewed up here. I'm, oh, oh, I'll go over it anyway. I'm not that worried about the, the, not that worried about this area, because again, it's mostly the same color as what's in the background. So I'm going to hit OK, and rather than actually knocking out the background, it does something much more useful. It just gives me a selection.

The camel is now Selected. I want to Save that selection, so I'm going to my Channels palette. And clicking on the Save Selection as channel button and here in my little alpha channel Thumbnail you can see a nice white outline of a camel. So I think this is probably pretty good. What I need to do now is use this mask to darken the background. The camel is currently selected not the background. So I'm going to invert my selection Select Inverse or Cmd+Shift+I. So now you can see I've got marching ants around the edge of the screen.

The selection on the camel didn't really change, because it's just the inverse of the selection, and the edge of the camel is still the boundary. Now I can go to my Layers palette and make a new Levels Adjustment layer. If I make an Adjustment Layer with a selection currently in place. Photoshop automatically builds a Layer Mask for that Adjustment Layer out of that selection. So, I've already got a mask in place so now I can simply throw in some darkening. And as you can see, the background is getting darker, the camel is staying the same.

So I get this very nice mask here. Look at the hair. It's a very clean mask all the way around. Obviously I don't want that extreme, I'm just going to move my black point over here to the edge of the data. I think I am going to take my midpoint and shift it a little bit. What I'm mostly focusing on here is this area in here. And this is the part where there wasn't enough total separation between the foreground, and the background. I like this stuff darkening up. Let me close this, turn this off. Here's before, here's after.

Getting a lot more depth in here it's really bringing out some highlights, and some of those lighter bits in the grass. I like that a lot. However, the sky has darkened up too much, it's kind of an unbelievable shade of dark. When I shot this, I, I knew that there were these telephone lines back there but there was nothing I could do about it. I can go in and paint those out later. I kind of like them now, I might keep them, I don't know. It looks like a musical staff or something. But anyway that's, that's an edit separate from any of this masking. I do know that the sky is too dark. Now normally to darken a sky I would use a gradient mask on a levels Adjustment Layer.

This would be a mask that would lighten the sky up here, I'm sorry I said, darken the sky earlier. To edit the sky it would apply and Edit the top and then ramp it off down at the bottom. And the way I would do that would be to create a levels Adjustment Layer. Lighten my sky up here and then take my Gradient tool and simply do this. So now with my mask in place you can see I have this ability to Edit the sky separately from the ground. Unfortunately it's also editing the camel, and if you look at my mask over here.

You see this perfect gradient over here. What I need is a combination of this gradient and my camel mask. And that's what I'm going to use, the calculations or calculate Dialog Box four. I'm going back to my Channels Pallet and I see here that I have my Alpha one channel, which is my camel mask. I'm going to make a new channel, by clicking this new Button down here, and I want to create a gradient in here. The problem is now I can't see my image, so I don't know where the Gradient needs to be. If I just turn on one of my color channels, that will show up as a reference. So I'm still editing my Alpha channel down here.

With my Gradient tool selected, clear this out of the way. So I've got this mountain range right back here. I think I probably want my Ramp to start about here and, and here. So here you can see my Mask is open at the top closed at the bottom with this nice gradient in the middle unfortunately it includes my camel, that's okay. I'm going to go back to my RGB, normal RGB display here and what I'm looking for is calculations, which I've now lost track of.

Image, there we go. Image calculations and this Dialog Box comes up. Don't worry about what's going on here because it's not configured right now. I don't worry about the layer that I'm working in. I want to just pick the appropriate Alpha channels, so I want to start with Alpha one, which is my camel mask, and I'm going to merge that with Alpha two. And if my blending mode is set to subtract, what's happened is it has subtracted alpha one from Alpha two, so I have my Background wide open. The camel's all knocked out in front of it, with the beautiful edge that I created before.

My foreground is all closed off. I think this is going to be a really nice mask for doing the edit that I want. I hit OK, and I end up with this mask down here. Back to my RGB view. So what I need to do now is, load this as a selection. That's very easy. I click and drag it down here to the Load Selection button and I get this mess. I can now just do the same thing I did before and create a new Adjustment Layer and it's going to automatically build a mask for what I need and now, if I come in here, this is not the edit that I wanted, just want you to see that my mask is working and darken, you can see that the sky is getting darker, the camel is not, not is the foreground.

So, my mask is working just fine. Now what I can do is just lighten the sky a little bit, just take a little bit of that extra dark edge that wasn't supposed to be there in the clouds. It's also removing a little bit of the blue cast. So let me give you a before and after. Here's before, here's after and that has not edited my camera at all. So calculations is the key to creating really complex masks where you need gradients in one place, selections made with other tools in another place It's very easy to use. Sometimes you have to play with the Blending Mode there a little bit.

Subtract or add is going to be the right option depending on the order that you put your masks in. Refine edge, meanwhile, is the key to getting these nice soft edge masks. If you were going for that Richard Abaddon look where you shot someone in front the wall, and you want to knock the wall out and just have white behind them. That masking technique that I used on the camel, is going to be what you're going to do to do that it's the key to getting a good mask around hair.

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