I mean, in the demo you posted, you can change the image/frame size with these lines
content: '<div id="fbreceptor" style="width: 600px; height: 600px;"></div>',
How can I get this to automatically determine the initial size of the image based on the window? Right now with that code it makes it 600x600. I've tried changing the values to auto, or into a percentage, but that doesn't work. Fancybox should change it automatically, but for some reason it doesn't want to (my pictures are much larger than the window). autoResize should be true by default, so that isn't the problem.
top: 0 !important;
margin: 0 auto;
I still want to be able to zoom in on them with the T Zoom. Or is this not possible? If not, that's fine too