Hello there! I'm working from a very large photo of a landscape I took. My printer can't print large enough images, so I ordered an enlargement online. I'm really happy with the photograph, but the shadows turned out darker than they looked on my monitor. I don't want to order another photograph. How can I lighten my shadows when I paint? Will doing so throw off all the other colors? In other words, will I ruin my realism by altering the shadow values?