When You Use Deep, Deep Blacks, You Can Begin to Paint with Light
There's a common guideline that the perfect histogram should look like a bell curve, high in the middle, and tapering down to gently touch the baseline at both ends. Poppycock.
Suppose you are looking at the picture on a television set, particularly an older CRT variety. It may look reasonably good, but if you turn the set off, you are likely to notice something curious. The face of the screen itself is probably some shade of gray. When you think about it, the color of the surface is the darkest color that TV can display. With all colors firing on full and combining, the screen will project white. With all colors completely off, what you would see is the base color of the screen. The closest it can get to pure black depends on the minimum brightness just as its ability to render pure white does on the maximum capable brightness. As the years have gone by, television manufactures have been improving their manufacturing technology to allow for darker background matrixes, and the advertising for such sets have touted the benefits in terms of improved contrast. Make backgrounds darker and you make the darkest shadows in the image darker. And so, they continued to sell new TV models.
A similar phenomenon can be seen late on a hazy afternoon, or on a foggy morning looking across the valley floor. The further you look into the distance, the more haze of fog you will need to look through, and the more washed out the blacks will be. Such low contrast scenes can have their own charm, but it would be unfortunate if we were limited this way all the time. A world without contrast means a world where everything blends into sameness.
But you can also experience the same thing when looking at most photographs. The contrast you see is the range of tones used in its creation. And a lack of contrast can result in an image that blends into all the others rather than one that one that stands out from the pack.
And yet the standard wisdom has it that an ideal histogram stays clear of either end for fear of clipping. Most introductory works on photography will instruct you to aim for a histogram shaped like the classic bell curve, tall and wide in the middle, and sloping down at both ends, but never, ever running up against the wall at bure black or pure white. That has always stuck me as curious. It only sort of matches the way I see the world with my eye.
Granted, most people wouldn't stare directly into the sun for fear of damaging their retinas, so we rarely encounter pure, burned out white. I suppose we could, but it would hurt, and so we shouldn't. But what about pure black? As you look around outside on a sunny day, your eyes attempt to compensate for changing brightness by dilating and contracting as needed to allow in more or less light. We don't tend to notice it because the process is automatic. But if it weren't, shadows would fall more quickly into inky blackness. Even still, dark shadows are a completely normal and expected part of everyday life. Overly burned out highlights aren't normal, but dark shadows are.
And yet we are taught to avoid them with our cameras and in our histograms. I say: poppycock.
Just like with those television sets that sold better because they could display blacker blacks, contrast sells in photography as well. An image with proper contrast will stand out against a sea of those that don't just the same as the eye is drawn to the best display in the wall of TV sets at the television store.
Now, we do need to make a distinction between the image as captured by the camera and the resulting image as printed or presented in its final form. I'm not necessarily speaking here of the raw file histogram as recorded. If there's a question as to whether you might want detail in some area, you'd better pick an exposure that preserves detail there. Once its gone, its gone. Shadows in the original image that are too dark no longer hold any secret, hidden details to be drawn out. They were never recorded, so they simply aren't there for later tweaking in Lightroom. But in areas that you know will be rendered in shadow, don't sweat the loss of detail in the camera raw image. And when making your adjustments in Lightroom, feel free to push even more detail into shadows if it will strengthen the impact of the image you are working on. An image can be simplified and made stronger by hiding some of the unnecessary details in the shadows.
In the film era, Fuji Velvia was famous for its dark shadows. And Velvia sold. Today we see photographers investigating High Dynamic Range (HDR) techniques and creating images as if the world had no shadows. I say its time for photographers to return to the shadows and embrace them.
Shadows should be allowed to be mysterious. They should tempt the eye both to look into the shadow and simultaneously to look away. But more importantly, dark shadows can create the background next to which we can render colors that stand out all the more. Follow the standard bell curve advice for histograms and you miss the opportunity for better contrast that flirting with darkness provides.
Be daring with contrast. Allow blacks to fall into shadows. It is only when you use deep, deep blacks that you can begin to paint with light.
Updated to add: for those curious where the title of this week's article came from, I feel obliged to give credit where credit is due. It is my paraphrase of a line in the episode commentary on the new Blu-Ray release of "Bellero Shield," an episode of the old science fiction show, Outer Limits. The series doesn't have anything much to do with outdoor photography, but its still a good show, and the new release looks great. The line just stuck with me when I heard it. Got me thinking.