http://www.nikonchat.com/nikon-angle-finder/
What is a right angle finder and why use it?
I found this angle finder on ebay … It seemed appropriate for the type camera I have … I have no idea of what makes … Can you explain me what this odes? Thanks indeed, Scott Here it is: http://cgi.ebay.com/Nikon-DR-4-Right-Angle-Finder-for-F5-F4s-F100 -N90-NEW_W0QQitemZ160160417444QQihZ006QQcategoryZ29968QQssPageNameZWDVWQQrdZ1QQcmdZViewItem I did not buy … I saw it and was curious as to what it does.
Basically it attaches to the eyepiece viewfinder lets you frame and focus looking down instead of looking through the eyepiece. It is a useful piece of equipment that you use a tripod lot. If you do not use a tripod much, probably will not have much use for it.
Seagull Right Angle Finder for SLR’s – by enjoyyourcamera.com