Use of CanonT-70 AE-1 lens on Rebel XT?

I am age 81 and have a number of expensive (in pre-1985 era) lens for

the Canon AE-1 and Canon T-70. I have been sticking strictly to

cameras like the Canon G6 but have now acquired a Canon Rebel XT. I

know that the older lenses will mechanically go on the Rebel XT. I

would think that for the zoom lenses I would want something like the

Canon 70-300mm F 4.0-5.6 IS USM and Canon EF 28-125mm 3.5-5.6 IS

lens to take advantage of autofocsing. But, what are the problems to

be encountered in using non-zoom older lens such as the Canon FD 50mm

1.4 or Canon FD 28mm 2.8? I realize I need to "go back to school" and

read up on the current camera technology. I realize that the area of

the digital sensors is much smaller than the old 35mm film area. But,

wouldn't a good 28 mm or 50 mm fixed focus lens from the 1980s give

comparable results to a newer Canon 28mm or 50mm lens?

You will find the sorry tale and answer to your question here:

 

http://photonotes.org/articles/eos-manual-lenses/

 

Your FD lenses will still produce excellent film images on your T70 though.

 

If you are used to shooting at 28 and 50mm on film, then you should consider the Canon 17-40mm f/4L or Sigma 18-50 f/2.8 - you have to allow for the crop factor narrowing your angle of view. The Canon EF 50mm f/1.8 is cheap but very good: on a crop body it's a suitable length for portrait work (same FoV as 80mm on film). Primes to research include the Tokina 17mm f/3.5, Sigma 20mm f/1.8, and Sigma 30mm f/1.4.

You can buy a cheap Hama adapter off of Ebay to mate FD lens to the Rebel XT. Its not high quality and you will end up with severely degraded optical performance. Its really not a practical way to go if you want to know the truth. But you can do it.

 

That said the adapter has a glass element in it to allow infinity focus. In effect it becomes a 1.25 teleconverter. If you add that to the crop factor of your XT, an FD 28mm lens on the XT will end up with the equivalent field of view of about 56mm on your AE1. An FD 50mm on your XT will look about like a 100mm does on the AE1. I want to stress once again, optical performance with this combination is severely degraded because of the glass in the adapter.

 

Personally I think trying to mate older FD lenses to EOS bodies is a waste of money. I don't know what the Hama adapters cost these days but they used to be anywhere from $50 to $100 on Ebay. Contast that with the fact that you can buy a brand new EF 50mm f1.8 for about $70 and it has superb optics. That makes a lot more sense to me than spending money trying to mate the FD lens to an EOS body.

 

On the other hand older manual focus Nikkor lenses are quite usable on EOS bodies. You can buy a $28 dollar Nikkor to EOS adapter from fotodiox that does not have a glass element. With this adapter you retain infinity focus and there is no degradation in image quality. With the price of older Nikkor glass these days, it is well worth considering.

If you already have a FD200/1.8, FD400/2.8, 500/f4.5, 800/f5.6, it may be worth it to look for a Canon FD-EOS converter. That converter yields good result. There is one (Canon FD-EOS converter) in ebay now. Starting bid is $890. Beware however: Seller has limited ebay selling.

I'm in your situation: New Rebel XT and boatload of old FD lenses. I got two FD/EF converters off eBay: Cheap $40 and expensive (supposedly multicoated) $96.

 

Save your money -- they're both pieces of fecal matter photographically. Neither add mentioned that both are 2x converters. Basically the conversion is not feasible because of incompatabilities between the two formats. See:

 

http://bobatkins.photo.net/photography/eosfaq/manual_focus_EOS.html

 

Don't know about the Nikon-EF conversion. If feasible, it might be worth exploring. Understand, however, increased flare problems with digital sensors might impose a penalty on this route, requiring, for example, use of sunshades and highly coated (and therefore more expensive) UV/Skylight filters.