Should photo-stack allow posts asking for photo critiquing? Perhaps limit to X number of images, and make the page community wiki.
Photo critique was voted to be off topic during the definition phase of the site, so I would say it should be regarded as such.
Question: Can I post a photo for critique?
Answer: (SiteName) is not a site for photo critique. However, if you have an image that turned out in a way that you did not expect, or where you want to achieve a specific result, questions about this are on-topic. Examples of such questions include:
I'm skeptical about general critiques, but I think that questions of the form I want to achieve X, I've tried A, B, and C and this is what I got are certainly on-topic.