man & nature # 55 ~ working with and improving the hand you are dealt
Wednesday, October 15, 2008 at 08:13AM 
End of the season plants • click to embiggenOn yesterday's entry, Mauro commented: "About the picture. I like this one a lot. What always strikes me is your dark tones management. If it does not offend you can I ask for some elaborations on that?"
To be honest, I am at a loss as to how to answer that question but, if you bear with me, I'll give it a shot.
For the most part, my picturing has always been biased towards dark tones. Over the years I have probably developed a dark-tone strategy when it comes to making and processing (analog and digital) my pictures but that process has been developed so gradually and incrementally that I can't really articulate it very succinctly.
In the digital domain, I usually look at my in-camera LEVELS dialog feature after making an exposure to be certain that I am not clipping the lower end of the tonal range, just as I do for the top end as well. On occasion I make a second exposure to protect the highlight end of things, which I later blend into my finished file.
It's worth noting that I primarily use Olympus cameras. Their sensors reach a bit deeper into the low end of the tonal range (which may be why they tend to clip at the upper end of the tonal range) than most other manufacturer's sensors. This tends to give me a little more information to work with in the dark tones.
Re: working with dark tones (in Photoshop) - I do all of my tonal adjustments in LAB color space using the LIGHTNESS channel. LAB color space separates the luminosity (lightness) values of the image from the color values of the image. The result is that tonal adjustments effect only the luminosity of the image and not the color. My tonal adjustments to the dark tones are almost always aimed at creating a slight increase in contrast.
FYI, I do all of my "heavy duty" sharpening on the LIGHTNESS channel in LAB color space as well - doing so virtually eliminates the color fringing artifacts that occur when sharpening in RGB color space. Consequently, if desired or needed, you can apply higher levels of sharpening (without ill effects) in LAB than you can in RGB.
I often isolate the dark tones of an image to work on them separately from mid and high values. Depending upon the image, I may simply use the lasso tool to create a feathered selection around the dark tones or, if the dark tones are not all in one area, I use the SELECT > COLOR RANGE > SHADOWS method of selecting the dark tones (I then feather the selection).
On more "difficult" images and working in RGB color space, I select the dark tones (using one of the aforementioned methods) and the make a new layer from the selected areas. I then set the blending of that layer to SCREEN. This always results in making the dark tones way too bright. So, using CURVES, I drag the lower end of the curve down until the dark tones start to look "correct". Even then they tend still be a bit too bright, so I use the layer OPACITY slider to adjust the amount of blending until I have the desired result.
IMPORTANT CAVEAT - Tonal adjustments on dark tones must be made with a very subtle touch - dependent upon many factors, there is the risk / probability of emphasizing any noise that may be inherent in the file.
A little bit of noise reduction in the dark tone areas may be needed after making tonal adjustments. Even though this may soften the dark tone details every so subtly. That, in fact, is how I like my dark tones to look because the human eye does not see the same level of detail in the dark as it does in the light.
It helps a lot to have reasonably accurate monitor calibration.
It should also be noted that none of this is an exact science. Every image is different, and therefore every image requires a different approach to making dark tone adjustments. Trail and error is the only way to work this out for yourself and your images.
So, there you have it. Without having you sit next to me while I work on an image, that's the best I can do.
Now if each of you will send me $125 for the workshop, we'll be all square.
Reader Comments (3)
I seldom think to work in LAB but this is a great reminder. I too, love the rich, deep but natural color in your images.
Thanks, reassuring as always. However I did express myself in rather obscure :-) way. I was more on the content than on the process. In your use of dark tones there is something I have also seen in the "cinemascapist" (something like a family culprit here), since you already spoke of mistery I was interested in the intentional and inspirational reasons (I doubt you do not have one). For in the series of decay you are more on the clear.
About the process I have to say that I started working in lab a lot of time ago (in 1996/98 rgb was far less usable in photoshop).
For the money let me invite you to an Italian restaurant if you decide to have a vacations in my country i certain you will find a lot of edges too.
lovely photo