Can I use any of the following lenses:
this or this or this or this with this adapter for my Canon Rebel T3i?
Please explain if any pitfalls that I may encounter such as infinity focus.
Also suggestions for cheap old high range zoom lens (such as 70-300mm) are welcome even if they are using another adapters
FD lenses are designed to sit closer to the film/sensor than EF lenses - so there is no adapter that can just place the lens in the correct location (because the correct location is inside the camera where the mirror is).
This leaves us with to options:
Adapter that places the lens farther than it's supposed to be - this has the same effect as placing the lens on a macro extension tube, you lose the ability to focus to infinity and from what I heard you are likely to lose the ability to focus behind macro range.
Adapter with a lens to corrects the distance difference (like the adapter you linked to) - so you just take an old lens (that is not as good optically as the new ones) and run all the light trough a second cheap lens degrading image quality even more.
So, if you mount FD lens on an EOS camera you have a choice, you can have an impractical focus range or bad image quality - and as an added bonus you also lose auto focus and other niceties of your camera.
If you want to use cheap old lenses you should choose lenses for a mount that has an adapter that can place the lens at the correct distance without optical corrections, basically and mount with the distance grater than what EF uses (you can use this list) - but you still lose a few decades of advances in camera and lens technology, don't expect the old cheap lenses to be nearly as good as the new expensive lenses.
I have a collection of 'vintage' lenses, most older Canon FD, although I also have Pentax and Nikon mounts as well. The best of the bunch is a Canon F/1.2 prime lens which I picked up used - the previous owner appeared to have remachined the FD mount - it isn't pretty but it works. There is a loss to infinity with all adapters (using on rebel t3). On wide open aperature they all suffer from a blurry/over exposed (I call it a 'bloom effect'). But for some scenarios I find it adds an interesting practical effect. I'm skeptical you'll have much success in combining a convertor + a 70-300 lens. I would opt for a less expensive but modern Sigma, which will have autofocus and IS on the higher end.
I have a chip on some adapters that provide exif data, but it doesn't actually reflect the current settings, they're just preset to whatever. So I don't find a whole lot of value in them.
I do know that Nikon, Pentax, and Canon haven’t changed the optical formulas much or at all on a lot of their good quality prime lenses, especially their 50mm’s. Some coatings have changed though. In fact you will find some of the older ones to be a much better build quality as they are strong metal vs plastic . But I do agree that there is no point to using a GOOD quality old lens with an adapter that contains a lens element in it, as it will most certainly degrade the quality. Should have got a Pentax, all legacy k-mount lenses work without adapters. And, I can say that they have a lot of good quality old lenses.
I was searching for this as I have a Canon 50mm that I was going to give to my friend with a t3i… Too bad…. it is fun using the old stuff.
