title: photo sizes available through Graph API / FQL and display in a custom viewer
body: <p>I create a photo viewer for fb photos in a FB canvas application. Therefore I care about photo size. It seems all uploaded photos in FB seem to be available in different sizes. I see in the graph API (http://developers.facebook.com/docs/reference/api/photo/) the term in the source property: "maximum width or height of 720px" but as well a width and height property. As well I have several photo sizes in fql photo (http://developers.facebook.com/docs/reference/fql/photo/).</p>
  
  <ol>
  <li>Are the photo sizes available in one category (src_small, normal, src_big) always the same or can they differ? I suppose they can differ.</li>
  <li>What are the formats FB supports? I suppose it is small normal and big</li>
  <li>How to conceptually deal with different sizes in a viewer? I suppose you need to fix the viewer area, eg. 3 (height) : 4(width). Now size an image inside the viewer by maximizing the height or width.</li>
  </ol>
  
  <p>Am I heading to the right direction?</p>