Canon F1.8 50mm Lens and T3i

[cyorkgo]

Hi,

Quick question for you pros out there.

I purchased a T3i and it came with the 18-55mm lens. I have an old 50mm 1.8 lens I am trying to use with it. I purchased a FD lens adapter and it connected it to the camera. It only focuses when i am about 10 inches from the subject. Why is that? Is it the adapter?

 

[drapeama]

FD to EOS (with glass) can achieve proper focus, but with image degradation. I've never been able to focus anything on my T2i with an adapter without glass.
Better to check for something else than FD mount, unfortunately.

 

[deltoidjohn]

To achieve proper focus using FD lenses on an EOS camera you need to use an adaptor with a glass element. This quality of this glass element is usually directly related to the price of the adaptor - hence why the Canon FD to EOS adaptor sells for $1500 2nd hand, while cheap versions only cost $50 on eBay. Apart from the fact that these cheap glass adaptors are of poor optical qaulity and will degrade your image, They also introduce a further crop (I think it's about 1.3x) to your image. So, factoring in your APS-C crop as well, your 50mm FD lens becomes almost a 100mm equivelant.

You should consider getting the Canon EF 50mm f/1.8. It's only about $100 brand new and even cheaper used. It has excellent optics (miles ahead of anything you'll get using adaptors with that FD lens) but terrible build quality and difficult, tiny focus ring.

 

[drapeama]

... They also introduce a further crop (I think it's about 1.3x) to your image. So, factoring in your APS-C crop as well, your 50mm FD lens becomes almost a 100mm equivelant...

I wasn't aware of that. Not very usefull then...1.6x cropfactor on the T2i + 1.3x because of the adapter...