For this drawing I really focused hard on the values and I’m really happy with the result. I also took a couple glances at the still life through my iphone and its “mono” filter that basically turned everything black and white. I didn’t do this to get the exact values of certain areas of the satsuma, but to get the relative values. In my previous drawing the leaves were much too light and I was surprised to notice when looking at the iPhone that the leaves were much darker than anything, very close to the value of the cast shadows.
Using alternate digital means to gather information is a great way to train your eye to see subtle things. For hundreds of years artists have had to rely on strange methods to remove themselves, or their brain, from their artwork and trying to look upon it with a new an discerning eye. Lots of painters turn their paintings upside down, or look at them through a mirror. I find that the best way to remove all attachment I have with a piece is to take a digital snapshot of it and view it on a computer or any digital device. Most of the time this will point out any glaring errors right away. But its not for the faint of heart, because if you want to really see all the problems in your work right away this is the way to do it.