Let me make this absolutely clear, this seems to be a subject that needs clarifying:
You are required to enter camera, lens (if not fixed lens camera), ISO, shutter speed and aperture in order to be eligible to adding the image to your gallery.
From version 1.1 (updated 20th Jan.) ONLY CAMERA AND LENS ARE REQUIRED FOR GALLERY IMAGES.
If the camera or lens is not the gear database, pick one that is similar. Again: if you do not find the gear, pick something that is similar.
ALL THE METADATA CAN BE EDITED LATER, TOO.
WHEN GEAR IS ADDED TO THE DATABASE, I WILL ANNOUNCE WHAT HAS BEEN ADDED. YOU CAN THEN CORRECT THE GUESSES IF YOU WANT AND ADD IT TO YOUR GEAR LIST.
You will not be not punished for guessing.
Of course we strive for accuracy of the data, being anal and picky photographers, but in this case I trust that we know that 50 1.4 or 50 1.8 is not a crucial error, 50 1.4 instead of 600 f/4 might be a noticeable. Your call.
The requirement to add this simplest metadata is all for good of the members. Having images connected to gear is highly educational for newbies, especially as it is all searchable and connected to reviews, member info etc.
I will make more use of the metadata database for members in many useful ways. AMASS makes stats of that data constantly even if that is not visible in the pages yet: http://photography-on-the.net/forum/metadata_totals.php