Ansel Adams was the well known photographer who developed the "Zone System". By identifying the lightness of an image and correlating it with processing film time, you could bring out every squeak of detail in shadow and highlight. A discreet connection between exposure of the film and the time spent in the developer bath is called a zone. Ansel Adam's Zone System was solving a problem of his day.
I think digital imagery and painting have a problem to solve too. One can spot a photo (although that's getting harder and harder) and distinguish it from a painting BUT what about the stages in between. The dilemma is particularly troubling when you use a tool like a computer. There are many MANY plugins (or programs that render a particular style onto the image) for Photoshop and Corel Painter alike. Do you reach the end product "painting" even though you use a computerized technique somewhere along the way? If you mix and match one computerized technique with another and another...is the result a doctored image or has it risen to the goal of being a "painting".
I think there are "zones" between a photo and its photo-painting. Consider a bird flying across the ocean. He flies a while and then drops down to a "Landing"...an island or rock ...which makes sense for him to pause or to eat. If there are "landings between one continent and another, the bird can fly and stop, fly and stop..." So too are there Landings which make sense between a photo and a painting...imagery which is neither BUT looks good, conveys your intent and is by any measure darn good art!
Let's give the "landings" a discrete number, say 1-7. A "2" would be an image that is quite photographic and a "6" would be quite novel and painterly etc. TIP: I like to look at my painting CANDIDATES and say "I can try to make a "4" out of this", or "This would be a great 7."
Here are some of my original captures and what I THINK the resultant picture's "landing" became...ie just how painterly was the file I sent to the printer?
Think in advance about how much deviation you intend to impart...how much change the image ALLOWS you to impart. There is no wrong answer.
So my TIP is, can you put a number on it?
Here is a gallery I completed in 2010. Can you see how every picture has a different landing...(or pitch...or degree of deviation from a photo). California's Northern Coast from Strength in Perspective.
Our most recent release is "Oregon Autumn Scenery". You'll recognize many of the above pictures there.