When drawing from reference photos, I often need to lighten shadows by using the photo editing 'Shadows/Highlights' tool. A perfect example was a recent Blue Heeler commission. The client emailed me a photo of a beautiful Australian Cattle Dog, a breed which is near and dear to my heart--one of my own four dogs is a Blue Heeler. Here's a picture of my sweet boy (indulge a doting doggie mama):

Adorable, yes?! I aim to capture those same expressive eyes in all my dog portraits, so the first thing I evaluate in a drawing reference photo is the eyes. Getting the eyes right in a portrait is extremely important since that is where we instinctively look first. In the client's photograph, I noticed that the eyes were shadowed and lacking discernable detail. It's hard to know what to draw when you can't see it!

Choose a photo editing software that allows you to lighten shadows without lightening the entire photograph. In Affinity Photo (and in Snapseed) the Shadows/Highlights adjustment tool leaves the lighter areas untouched while increasing the exposure in the darker areas:

There are those eyes! This adjustment also increased the level of visible detail in other dark areas like the nose and ears. The Shadows/Highlights adjustment is also useful for animals with dark or black fur, allowing you to create a drawing that has more form and depth. Here’s the before and after of our drawing reference photo: