thanks for your comments.
, you are right about the contrast. The first photo was actually very different from my painting and I'm not pleased with it. I think because of some intelligent feature in my camera settings then this became far too bright and also distorted colors.
Here is a new photo, it is better although a bit too reddish and the sky too dark and saturated, but in general somewhat similar to my painting. I've also been tweaking the painting a little more.
I find Reni's composition fascinating and powerful. When I was painting this I began to think that Reni must have had one model for the face, probably a boy or a young man, but another model ― much more muscular adult for the body. He depicts the spiritual strength of John the Baptist by showing a muscular body I think.