I've created a file geodatabase in ArcMap 10.1, with a feature class to which I have attached images. I'm trying to figure out how to control how these images are displayed. All I have found so far are statements to the effect that the Windows default image viewer will be used, but this is not accurate. Instead, what is happening is: if I view the attachments via the Identify tool, they pop up in Windows Photo Viewer (which is in fact my default image viewer!); if I view the attachments via the HTML Popup tool, they open in a very basic window (some kind of internal Arc browser emulator, maybe? I don't know) within ArcMap; if I view the attachments via the Layer Properties: HTML Popup: Verify interface, they open in Internet Explorer (my default web browser).
I would like for attached images to open in Windows Photo Viewer no matter how I access them, or at least with some kind of image viewer that can zoom in and out. Internet Explorer would work just fine, too; so would ArcMap's built-in image viewer thing, if it could be told to behave in a more useful fashion. At present, the window in ArcMap in which attached images open has essentially no functionality. It's a window, the photo is in it, it has some scroll bars at the edges, that's it. This is inconvenient with images larger than the current screen resolution, since you can't view the whole image at once. Instead you're stuck zoomed in to 100% resolution and you've got to twiddle around with the scroll bars to look at different parts of the image. Making all the images smaller would solve that problem, but loses information; ideally you want to be able to view the whole image, or zoom in to details--this is why essentially every image viewer ever made *except* this thing in ArcMap can zoom in or out!
So my question boils down to: How (either by changing the program used to open images, changing behavior of these image windows in ArcMap, whatever) do I get HTML Popups to display large resolution images in a way that allows me to zoom in and out?