7&8 brief notes

Lesson 7
* 3 auto commands
 -  Choose a command and it does its thing. If you like the result you keep it, if you don't you press control z  and try something else.Made the darkest pixels as dark as it can get and the brightest pixels as bright as it can get without changing one channel differently than another. Which means that this command never affects the color cast. So if you like the color cast of the image and you just want to increase the contrast then auto contrast is the way to go. Alright finally going to scroll down to auto color which is the most complicated of the bunch. And go ahead and click on the auto color layer as well here inside the layers panel.Go up the the image menu and choose auto color. This time what Photoshop has done is it's located the darkest pixel in the composite image and turned it a neutral black. Then it located the brightest color in the composite image and turned it a neutral white and then it did it's best to locate the most representative mid-tone pixel and it turned it a neutral gray. This isn't always the way it turns out but in the case of our money we have some neutral shadow lines, we have these neutral highlights in the paper, and we have neutral gray values throughout except in those areas where we had an awful lot of color as in the case of this treasury stamp, the serial number, and these large digits down here in the lower right corner.Alright so I'll just go ahead and press control 0 or command 0 on the Mac to zoom out so that you can see all four of the bills. The unmodified one in the upper left corner, the auto tone modification in the lower left, the auto contrast in the upper right, and the auto color down here in the lower right. Of the three, auto contrast ends up producing the best result where this particular image is concerned. But as we'll see in the next movie, things can work differently with a continuous tone photograph. And that's my overview of the three auto functions auto tone, auto contrast, and auto color here inside Photoshop.

*Automatic brightness / contrast
 - Start with the top layer selected Auto Tone and then  go up to the image menu and choose the Auto Tone command. Now remember that Auto Tone is correcting each and every channel independently and as a result, it has a habit of introducing color cast. And in our case, we have a kind of greenish goulish cast going on. Alright, go and turn that layer off, click on the Auto Contrast layer, go up to the image menu and choose Auto Contrast and we end up with this much better balanced image here.not always the case but if all your image needs is more contrast, it doesn't need any color reconfiguring then this command stands a chance of working fine. Alright, now  go ahead and click on the Auto Color layer.  Turn the Auto Contrast layer off and  go up to the image menu and choose Auto Color. Recall that this is the one that tries to find the darkest pixel and make it a neutral black. It finds the brightest pixel and makes it a neutral white and then it tries to find a representative mid-tone pixel and make it a neutral gray.Go up to the image menu and choose Auto Tone which is a command that pretty much wrecked the $100 bill but it does a great job of bringing out the colors inside this image. And then finally, just to make sure the image is looking its best, revisit the image menu, choose adjustments and then choose Brightness/Contrast and a click on the Auto button and sit here and wait for it 'cause it does take a moment or two for this command to work but in due time, will see a brightness value of -4 and a contrast value of 36 and just to make sure like whatsee,turn the preview checkbox off for a moment and then turn it back on and you can see that we are gaining just a little bit of extra contrast.At which point go ahead and click okay to accept that change. Then  press Shift + F to switch to the full screen mode and  zoom on into turtle. And just so we can see the difference, this is the original version of that photograph. Exactly as captured it with a consumer grade underwater camera and this is what it looks like now. Thanks to the application of the Auto Tone command working together with the Auto button inside the Brightness/Contrast dialog box here inside Photoshop.

*Custom brightness / contrast
- Go up to the Image menu, choose Adjustments, and then choose Brightness Contrast to bring up the Brightness Contrast dialog box. And then you presumably want to go ahead and start by clicking on the Auto button to see what Photoshop comes up with all by itself. Which is not half bad, by the way. If  turn off the Preview checkbox, you can see that previously the image was dark and murky and now if  turn Preview back on, it's bright, high contrast, and it looks pretty great. But that doesn't mean it need to stick with these values. Decide that Photoshop is adding too much contrast, in which case,  take that Contrast value down. It might also decide that the image isn't quite bright enough, in which case  increase the Brightness value. Or if it's too dark,  can decrease that Brightness value. Now something to know about Brightness Contrast, is that these days it's incapable of clipping pixels. And by that  mean that it doesn't allow you to clip your shadows to black or your highlights to white. Now a lot of folks still steer clear of this command because back in the old days it always clipped pixels. Press Shift along with the Up or Down Arrow keys in order to move that value in increments of 10. So this is what happens if  press Shift+Down Arrow and this is what happens if  press Shift+Up Arrow. And then finally, another way to work, in case you're interested, is you can scrub directly on the word Brightness, or the word Contrast in order to modify that value on the fly. And if you want to change this value in increments of 10, then go ahead and press this Shift key as you scrub. Go with a Brightness value of 50 and a Contrast of 10, at which point go ahead and click Okay to accept the change. And now  press Shift+F to switch to the full-screen mode. And just so we can see the difference we've been able to make,press Ctrl+Z. This is that original hawksbill turtle that  captured in front of the shipwreck on a recent dive. It's a great shot because managed to get it, but it looks pretty murky, and this is how it looks after a quick and easy application of the Brightness Contrast command.

* Reducing contrast with shadows / Highlights
 - Change that Channel setting to Luminosity, and notice, if go ahead and update the histogram, that we have a very spiky histogram indeed, with an awful lot of shadows running against the left-hand side of the graph, and a ton of highlights running into the right side of the graph, and then we have this big dip in the midtones. The sign of a hot, high-contrast image. And so one thing we could do is bring up the Adjustments panel by clicking on that black and white circle, and then, Alt + click or Option + click on the Brightness/Contrast icon, and go ahead and call this guy contrast down, for example, and then,reduce the Contrast value to its absolute minimum of negative 50. And that does virtually nothing, it makes a slight contribution, but nothing like what we need. To take this Colors value right here, down to zero, because otherwise you're going to increase the intensity of the colors inside your image, and you really don't want to do that. And now, you can go ahead and set the amount values to whatever seems appropriate. G o to keep things simple, by setting both the Shadows amount, and the Highlights amount, to 50%, like so. And now, see the histogram again. Notice the top is still shaved off, but as soon as go ahead and click OK, in order to accept that change, we get a much better contoured histogram.Click on the Update button, you can see that it looks to be in pretty darn good shape. So notice that we now have these tapering shadows, as well as these mostly tapering highlights. We still have some spiky action right there at the end, and there's not really anything we can do about these so-called specular highlights right here, that are dancing off the surface of the water. But we now have a ton of midtones, which is a really great thing. So, just to give you a sense of the difference here,  go ahead and press Shift + F to switch directly to the full screen mode, and then  zoom in on  image, and if press Control or Command + Z, this is how the image looked when  first opened it, and then if  press Control or Command + Z again, this is how it looks now, thanks to our ability to settle down the highlights and open up the shadows in an extremely high-contrast image here inside Photoshop.


Lesson 8
* Identifying the color cast of a photo
 - First step is to make sure your Color panel is up on screen. If it isn't, go to the Window menu and choose the Color command. And then you want to go ahead and select the Eyedropper Tool. And if you're seeing some other tool in the slot, then just go ahead and click and hold on it and choose the Eyedropper Tool from the fly out menu. You also have a keyboard shortcut of "i" for Eyedropper. Have a white balance card or a gray card sitting in the shot. However, this is just a candid snapshot. So  go to look for something that ought to be,  either white or gray. You're going to see this color ring with the old foreground color down at the bottom and the new foreground color at the top. You're also going to see the color identified here inside the Color panel and you can see based on the predominant color inside this field right here that we are looking at a green cast. Set the primary colors of red, yellow, green, cyan, blue and magenta which are industry standard color names. Go ahead and set those primary colors in larger type than the secondary colors of orange, lime, turquoise and so forth. And now  also gone ahead and labeled every 15 degree location as well although obviously, these are subjective color names. In any event, we've now manged to identify that the color cast for this image right here falls somewhere in the neighborhood between yellow and full on green and you may recall that the value for the teeth was 140 degrees which is getting into cyan territory.

* Correcting a color cast automatically
 - An average an area five pixels wide by five pixels tall, so 25 pixels at a time. And now notice if  click, once again inside that brick, now get a slightly different hue value of 77 degrees. Now let's walk through what these values mean here. H stands for hue, which is the core color of the image, as identified in this color wheel, starting at zero degrees for red and wrapping all the way back to 360 degrees, which again, is red.  Intensity of the color,  we have B for brightness, which goes from zero, which is black, all the way up to 100% which is the brightest version of any given color. Now the saturation value is perhaps the best indicator of the color cast of an image. And that's because it tells us how intense the color cast is. If we see a neutral element inside the image has a very low saturation value of let's say 3%, that's a very good sign.  ultimately a blue color cast, but we have a much lower saturation value as well, of just 4%, which is pretty darn neutral, which means that we at least got the brick looking pretty neutral, the teeth however, if  go ahead and click and hold inside of them, with the eye dropper tool, you can see that we now have a hue value of 236 degrees, which is blue by the way, and you may recall from the previous movie that formerly we had a hue value of 140 degrees which is green, but our saturation value has gone up to 10%. So it's very possible that what we've done here is change what was formerly a green color cast to what is now a blue color cast . it looks like a closer match for the actual scene. Now, while Auto Color happened to work great for this image, Auto Tone might work better for another image, or just as likely neither command will make a positive difference, in which case we have to make a manual color adjustment.

* Manually adjusting colors with color balance
 - Start by trying the Auto commands, but notice if  go up to the image menu that Auto Tone through Auto Color are dimmed and that's because currently have an adjustment layer active. Those commands are only applicable to pixel-based layers. So  go ahead and click on the background to make it active and then  go up to the Image menu and  start with Auto Color since it worked so well in the previous movie and that just actually sort of depletes some of the color from the image. So press Control + Z  to undo that change and then  return to the Image menu and  try Auto Tone, which does a pretty good job but not really good enough.Go ahead and press Control + Z . Now, it turns out there's a lot of ways to correct color balance inside of Photoshop, but generally a good place to start is color balance and to add a color balance adjustment layer you go ahead and click on the black and white circle at the bottom of the Layers panel and then you choose the Color Balance command. Or if you want to name the layer as you create it, go ahead and bring up the Adjustments panel by clicking on its icon and then go ahead and Alt + click or Option + click on the second icon in the second row, the one that looks like a little pair of scales.Go ahead and switch back over to the image at hand and  change the Tone option to Shadows. And then  went ahead and took the magenta green control up to plus 20 and  took the yellow blue control down to negative five. And  making these modifications using the arrow keys so you can either press just the up or down arrow key or you can press Shift along with an arrow key to modify a value in increments of 10. And then finally  went ahead and switched the Tone option to Highlights and  clicked in this yellow blue setting right there and  pressed Shift + up arrow a total of three times in order to increase that value to plus 30. Go ahead and turn that layer off. That is the original color cast of the image and then if  turn the adjustment layer back on we see the new colors inside the image. And again, it's a subjective modification. You might very well come up with different settings, but that is at least one way to manually adjust the color cast of an image using a color balance adjustment layer here inside Photoshop.

* Making even more color with vibrance
 - double-click on its thumbnail in order to bring up the Properties panel. And then click in the Saturation value, and  press Shift-down arrow a couple of times in order to reduce the color noise, as we're seeing here. Now, of course, that doesn't totally get rid of it, but it makes a big huge difference. Now,  go ahead and select the Vibrance layer once again, and  take its saturation value down to +70, let's say. And then  go ahead and zoom out from the image by pressing Control-0 or Command-0 on the Mac, and  select the Vibrance value, which  can do, of course, by pressing Shift-enter, here on the PC, or Shift-return on the Mac, and go ahead and crank it up to its maximum, and then  press Shift-down arrow a couple of times in order to reduce that value to +80. Saturation value of +70, and then, where Hue/Saturation is concerned, we have a saturation value of +60. At which point, go ahead and hide the properties panel, so that we can better see the image on screen.  also want you to see what's going on with the channels, so  go up to the Window menu and choose the Channels command in order to bring up my Channels panel. And now, notice the differences between the Red channel, which we're seeing now, notice that it's quite noisy in this area of coral, and then, if  switch to the Green channel, we have a very different-looking effect. Switch to the Blue channel, things are more different still, with a very bright sky and some very dark coral. And that is definitely quite different than what we were seeing in the Red channel .  Now I'll go back to the Layers panel and  Alt- or Option-click on the background. That is the image as it appeared at the beginning of the previous movie, and that's the image as it appears now, thanks to our ability to draw color out of even the most drab image, using a Hue/Saturation adjustment layer and then enhance those colors that much further using a Vibrance adjustment layer, here inside PhotoShop.

* MORE ACCURATE / FULL NOTES / EXPLANATION ON LYNDA.COM