Would it be possible to have a picture viewing popup window that is sized to be no larger than the screen? Also have the picture default to a zoom level that shows the full picture with no scrolling, and a zoom level slider to enable you to zoom in up to the 100% sized picture to see more detail if desired. I know some sites have that, but didn't know if that was easy to implement or not.

At the moment oftentimes you go from a small square crop that maybe isn't a good representation of the entire picture to a full size picture that requires scrolling to view it all. I realize that uploading a smaller resized picture would help that to some degree. But, it seems like a more adaptive picture viewer would improve everyones experience regardless of their screen size.

I was going to post a suggestion about the square cropping of the thumbnail photos, but I did a search and see that topic was already covered a few months ago. I can definitely understand the preference for square crops for the plant database pages to keep them organized looking. I think elsewhere on the site, especially in the forums and articles that displaying thumbnail pictures resized but uncropped would be more useful. It has already been covered well in the other thread though. Just wanted to add my two cents.
The thread "Thumbnails and aspect ratio" in Site Talk forum

I use the free Image Zoom extension for Firefox. I suspect there are similar browser add-ons for other browsers. In my opinion, it is far better than relying on each individual website to have the capability.

http://imagezoom.yellowgorilla...

I'm just happy when photos are in focus and have good lighting (and no fingers).
Zooming, scrolling, etc. are not a problem for me when the image looks good.

I tried one of the browser add-ons that was an automatic image resizer, but it didn't work when the image loads in the pop-up viewer here. But, I found that if I just disable javascript for this site, the image loads like a regular link (not in a pop-up) and then my browser automatically scales it to not be larger than the browser window. That seems to work pretty well and I haven't found any downside to disabling javascript here, at least not yet.

I haven't tried anything with my tablet yet, it may be more problematic. I don't know if the mobile versions of the browsers let you disable javascript on a site by site basis. I have more trouble with the current pop-up viewer on the tablet than the computer. The x button to close it is so near the edge of the screen, that it doesn't register my finger taps much of the time. I have to move it around to try and find the sweet spot that lets me close the pop-up.