Monday color. And monochrome

sharp red pond lily
We’re going to go beyond a simple color post with this one, because it’s more interesting that way. I started off with a macro shot of a small (as yet unidentified) pond lily, which loses a little bit when displayed at this size because the contrast in focus is distinctive at a larger scale, but so be it. The contrast in color is distinctive too, and it’s images like this that make me start playing around in the photo editor to see what becomes of them in monochrome.

same image in red, green, and blue channelsI’ve mentioned this before, but reducing an image down to just one (of the three) color channels can produce quite interesting effects in monochrome; in this case, all three of them had their positive points. Digital images are made up of three primary colors, and even the monitor you’re viewing this upon is breaking the image down into those. Every color displayed is a mix of red, green, and blue pixels, which is what “RGB” even means. And for some images, removing two of the colors (usually called “channels” in editing programs) can produce a marked difference in contrast and rendition. From top, this is the same image in the red channel, then the green, then the blue – the blue is the most surprising, since it’s often the muddiest when doing this. So what you’re seeing is the relative strength of the red ‘light’ in the first of the three here, rendered as monochrome – in other words, only light levels, and counting only the red light. So the purplish-pink blossom becomes almost white, because it has a lot of red in it. And since purple is a mix of blue and red, when we go down to the blue channel at bottom, we find the blossom is fairly bright there, too.

But what about the leaves themselves? Why are they even showing up in the red channel when they’re green? But this shows us some of our bias, the simplifications of our color names, as well as a trait of RGB colors. The pads are actually more chartreuse, or yellowish-green. And a curious aspect of RGB coloration is that yellow is a combination of the red and green pixels – seems counterintuitive, but you can see it for yourself right here. Now, note the pad leaf directly underneath the blossom’s shadow. It appears the greenest in the full-color version, and it’s noticeably darker in the red channel, but almost indistinguishable from the others in the green channel; same amount of green, but less red, which (when combined) means less yellow. Simple, right?

If that’s not confusing enough, the leaves in the blue channel are darkest, because yellow (or red-green if you like) is the opposite of blue. For color editing, if you increase yellow, you’re reducing blue. Or just look at it as if you’re increasing red and green while leaving blue alone – same thing, really. But overall, each channel provides a different rendition and ‘mood,’ if you will, to the monochrome image; each might have its own application depending on what you want to accomplish with the photo. The red channel really highlights the difference between the blossom and its shadow, while the blue channel makes the blossom itself stand out against everything else. Just something to play with.

Now let’s take a look at using the ‘Curves’ function in Adobe Photoshop to tweak your images more to your liking; now that anyone can use Photoshop online for free, it’s easy for me to show techniques within the program without feeling guilty that not everyone will invest in a ridiculously overpriced (for well over a decade) piece of software. In Curves, you can change the brightness of all three channels, or just one channel at a time, very selectively. Let’s say you want to increase the difference in certain colors, but only in the brightest parts of the image, or even in a very narrow band of brightnesses – say, in a sunset sky. Take a look at the original straight from the camera:

Sunset over pond with subtle colors
Not an award-winner, but it was the sunset I had to work with that evening. You can see how the reflection of the sky in the water produces more definition in the colors than the sky itself, which got washed out a little bit – this is easy to do with sunsets, because there’s a huge difference in light levels between the sky and virtually anything else, and the camera can only capture a certain range, less than our eyes can see. Now here’s a tweaked version:

sunset over pond, enhanced contrast
There are only two changes: the light levels in the brightest portion of the sky right in the middle (where most people want to look anyway,) and the shadows down at the bottom. Now the contrast in colors stands out a little better, while the darker bottom gives slightly more sense of being under the canopy of trees. Never get too heavy-handed when doing Curves adjustments, because subtlety looks more natural.

Here’s what the actual Curve plot looked like:

sunset enhancement showing Adobe Photoshop  Curves plot
The black wavy line across the middle of that X-Y graph is the controller for the light levels from darkest (bottom left) to brightest (top right,) and always starts as a diagonal line, seen in ‘shadow’ behind it. Meanwhile, that spiky grey area in the background, running mostly along the bottom, presents the actual light levels captured in the image – a lot along the left side, meaning most of the image is black and dark grey, but a little all the way across (meaning the image has a range of light from pure black to pure white) with a few spikes at the bright end along the right, which is those sky colors that are almost washed out in the original. Think of it as counting all of the pixels and assigning a brightness to each; there are more dark pixels, so more in the bar graph to the left. When you click on that solid line with the mouse, you produce a point on the line that you can then drag up or down to make brighter or darker than the original – you can see I darkened the entire line a bit (deepening the shadows towards the bottom of the image where the colors got darkest) and did a lot of playing around at the upper end of the line, which made the contrast between very narrow areas of the brightest part of the image enhanced to a greater degree. It can take some experimenting to see what works best, but it’s my favorite method by far of tweaking an image towards the effect I prefer. Try it out on your own.

Remember, too, that you can do this for each of the three color channels, selectively enhancing the blues for instance while leaving the reds and greens alone. This is a good way of counteracting the color cast that might come with different light conditions.

And then, because I was once again on a monochrome kick that day, I converted the entire image to greyscale. In this particular case, no color channel by itself provided a decent effect, so I just went with monochroming (it is too a word) the whole image.

sunset over pond in enhanced monochrome grayscale greyscale
Monochrome is all about producing the best contrast, since that’s all the image has, so it benefits from tweaking the Curves much more often than color images. And in this case, the Curves got a greater kick because the contrast between the pink and blue portions of the sky became more subtle (or nonexistent) when the color went away. So, this:

Sunset in monochrome showing Photoshop Curves function
So much for subtlety, eh? But since the contrast between colors is no longer a factor, the contrast between light levels may need to be enhanced, and thus the wilder curves in the graph – it didn’t seem to become unsubtle in the image, did it?

Again, very little change in the darker portions of the image, because reflections from water are always darker than what they’re actually reflecting (polarized, too) and so they didn’t need much changing – always be careful not to make reflections the same brightness or brighter than what they’re reflecting, because it won’t look right.

This is all illustrative, because I wasn’t terribly happy with the originals in the first place (I’ve done better, in other words,) and the sky wasn’t ideal; for one thing, some of the clouds that were even catching the sunset colors were actually jet contrails, and too straight – you can see this along the left side, both top and bottom. I positioned myself among the trees solely to try and disguise this as much as I could, so you’re actually seeing fewer contrails than existed at the time. But there’s another artifact of tweaking the Curves that popped up, and you may have already noticed it. Look at the larger leaves near the top, just right of center – see the halos? Since they were out of focus in the original image, and thus forming a full spectrum along their edges between the blackness of shadow and the bright sky beyond, the selective contrast tweak became very unnatural right there (it appears, far more subtly, in the tiny leaves against the water right near center, too.) The History Brush, which reverts the image back to an original state only where you ‘paint’ it, might have helped, or just blurring the edges a tiny bit with the Smudge tool with a very small setting could have worked. I left it in because it shows how little telltales can sneak in and look weird during editing, so keep an eye out.

Experiment, get a feel for what works best for you, and have fun with it!