That's helpful information, Ernicus. Thank you.
It would have been helpful if any of it were actually true, but in my experience with FD adapters, none of it was.
I have and use a $30 adapter and just looking at the way the mount is made, I don't see how it can even touch the camera's contacts, let alone damage them.
It's also definitely "worth chit". This chatter is much like the "kit lenses suck" chatter that we so often encounter that's also not true. The results I'm getting with it to mount a 500mm f/4.5 L prime lens on a Canon 7D are quite good, and well worth it. Without contacts, it can't "read" the lens though, so EXIF defaults to saying it's a 50mm, and there's no aperture control to speak of, so I always shoot it wide open. Also, without the lens in it, it can't focus to infinity, so that cheap lens in the adapter is certainly going to bring down IQ, even if it's not noticeable to me, and on full frame cameras, CA is noticeable in the corners and near the edges because of it, not to mention there's some vignetting on a full frame body (all with the 500mm I'm using), which is why I'm now using it exclusively on the 7D, which is working out VERY well for me. Examples are here:
http://www.thephotoforum.com/forum/nature-wildlife/294261-critter-shot-500mm-f-4-5-l-fd-mount.html
The best adapter you can get, other than possibly the limited edition ones that Canon put out for a short time after switching from the FD to EF mount (that go for something like $1000+ when they rarely show up on
ebay), is, according to most knowledgeable sources on the subject, the custom individually hand-made adapters from Ed Mika, and they run $150, not "upwards of a couple hundred bucks". From what I can gather, they're every bit as good as the original Canon adapters, possibly even better. I'm just about to order one myself to take it up a notch from the $30 product I'm already getting great results from. Read about them here:
FD & FL Lenses on your EF Body « Canon Rumors and here:
EdMika EF-FD 0.75mm glassless brass adapter - a set on Flickr
As long as you're okay with manual focus, there are some good deals to be had on FD mount lenses. Keep in mind that they're old, used, have possibly been banged around, and some weren't necessarily great lenses to begin with, so it can be a bit of a crap shoot. But especially for the longer, bigger, L lenses, and the more expensive specialty lenses like the 35mm tilt/shift, they were generally taken very good care of by their owners, and the odds go up that you'll get some quality glass and images from them, while saving a ton of money in the process.