Is it possible to use the 'drupal commerce' distribution for selling images from a photographer?
The images must be in a secure folder. After the visitor has payed with visa or mastercard, he can download the image. In fact it's the same principle as any other stockphotography webshop.
If so, can you give me some tips on how you can start to build it?
Yes; this can be done easily with the commerce_file module. There's also a specialized distribution available called commerce_downloads with this preconfigured. You could either use that as your starting point, or set it up in a separate directory to see how it's configured and add those settings to your existing commerce site if you already have one.
You can see a screencast about it here:
http://commerceguys.com/blog/commerce-module-tuesday-commerce-file-screencast
The individual projects are here:
