While taking some snaps I wanted to update my Profile’s First Life picture but I knew from experience that despite the system wanting to save every in-world snap at 512 pixels square or a version of that, the Profile image requirements vary from tab to tab. So an image I might use for the First Life picture would be horribly stretched for use as a Pick pic. Why can’t users save in-word snaps in custom ratios to match in-world applications as detailed in the official system specs shown below? One day I’ll get off my lazy butt and file a suggestion. Until then I’ll dutifully save images to the hard drive and resize them as needed. At least that gives me a format-free original I can use for other purposes if needed.
Aspect ratios of profile, place, etc. pictures — all of these were measured at UI size = 1.000:
▪ Search > All for “Classifieds”, “People”, and “Places” – 4:3 (256×192 pixels)
▪ Search > Places and Classified tabs – ~7:5 (398×282 pixels)
▪ Search > Land tab – ~7:5 (358×252 pixels)
▪ Profile > 2nd Life tab – ~4:3 (178×133 pixels)
▪ Profile > Picks tab – ~16:9 (288×162 pixels)
▪ Profile > 1st Life tab – 1:1 (133×133 pixels)
▪ Profile > Classifieds tab – ~3:2 (206×137 pixels)
▪ About Land > Options tab – ~3:2 (178×117 pixels)
▪ Group Information > General tab’s “Group Insignia” – 1:1 (126×126 pixels)
The Poultry Report 
It gets even more complicated since SL does not really like the upload of arbitrarily sized images and tends to snap them into a 512×512 (256, resp 1024) pattern. So best results you get when you work in the desired resolution in a graphics program, then PRIOR to uploading rescale the image yourself to the nearest 256/512/1024 square resolution and THEN upload it to SL.
Btw – your list is themost complete I have seen so far. Thanks!
Thanks, Peter. I got the list from an SL Wiki somewhere about a year or so ago. It’s been handy.
When I upload image I make note of the original dimensions in the Description field so I can properly proportion the prim face. But SL needs to let us set these “odd” sizes when we take snaps saved in-world or standardize the aspect ratios of the image holders in the info panes.