In my 40 years of copying paintings for artists I see a recurring problem to which I can offer a solution.
The Problem: Paintings done using reference photographs have too much contrast.
The Reason: Our eyes see a range of tones that stretch from 400-to-1 all the way to 10,0000,000-to-1 depending on various conditions. Film and prints don’t. Take an object seen by our eyes as jet black and put 400 times more light on it and it will look pure blank white. There are a lot of incremental steps of gradual lightening until we reach white. Want to guess what film/print technology would do in the same scenario? Photograph the object to look jet black and then add…32 times more light before it goes to white. That means that the tonal range of the reference prints is missing most of the subtleties of gradation steps that we appreciate with our eyes viewing the original scene. The lights become far too light, too soon, conversely the darks. Many a person, ( read: painter ), would assume that a picture doesn’t lie. Really, though, it doesn’t tell the whole truth. Those missing gradations of tone make the picture very contrasty and if an artist paints from that reference, the painting is bound to have too much contrast. Once one stares at photographs intensely for a while it becomes very hard to be discriminating about how to adjust the tones for a painting; the photograph takes on a mantle of the authoritative rendition of the scene. An artist trying to adjust the tones from the reference photograph to something softer on the canvas often feels that the results are confusingly wimpy, not containing enough contrast. He/she doubts the interpretation because the authoritative reference is always boldly staring back, stating its own case.
The Solution: Take at least 3 exposures of each reference scene; one that is too light, but that shows the darker parts of the scene with a lot of detail, a normal exposure for the mid-tones, and one that is too dark but which shows well the highlights that you want detail in. This method has two great functions: it allows one to see detail throughout the entire useful range of the reference area, therefore the artist doesn’t have the vexation of having to invent details and secondly, it forces the artist to start from the beginning of the interpretation process to establish his/her own criteria as to how light/dark the extremities of the contrast range will be and not be so distracted by the shortcomings of the photo-technology. The truly personal interpretive style of the artist will be much more apparent and appreciated.