I’m a big proponent of working from life or memory. There are so many benefits from working from nature that it would be hard for me to list all of them and how they affect your painting. Having said that there are times when working with photos can be helpful.
Because of the lens, the background appears larger than it really is
one type of lensflare
Depth of field blur; the background trees were only a few feet away
perspective distortion and extreme value shiftsWatch out for values; the range is small for cameras and so the low or high end gets lopped off and things turn black in the shadows or white out in the lights. It is better to look at the relationships of the lights and darks and use that as your guide instead of copying them exactly.
the camera can't capture the value range in this scene so color is washed out
Digital cameras use interpretive algorithms, so color is not accurate either. They have to take what are essentially continuous tones and colors of nature and chop them up into little squares of color and value, to do this they average things, sometimes this works but most of the time it doesn’t work well enough for painting things only from a photo. It is better to use photos for shapes and details and outdoor sketches and observation for color and value accuracy.
I painted the background for this painting on site marking the color notes of the boat as it passed by;
in the studio I painted it again on a new canvas adding the boat using photo reference for details and my outdoor painting as a guide for color
Most of my paintings are done from life or memory. When I do use photos I limit them to the things I know they are good for and use them in conjunction with color sketches and drawings. They are never a substitute for painting from life but in their proper place they can be another effective tool for your art.