Lens Compatibility

[Mike1313]

Hi everyone...I'm new here so this question has probably been answered many times but here goes anyway: I have an old EOS Rebel K2 SLR with a couple of Sigma lenses,will these work on a T7i?? Thanks 

[MikeSowsun · Accepted solution]

Most film era third party lenses have compatibility issues with modern Canon digital SLRs. In the past Sigma could “re-chip” the lenses so they work, but I don’t believe it is possible any more.

Even if the do work, they will not be as good as the kit lenses that come with the T7i. The Rebel K2 is a Full Frame camera and the T7i is a 1.6 Crop camera, so your lenses will also not be as wide angle as you are used to. 

[Mike1313]

Thank you for the info Mike,I sort of figured that was the case but thought I would double check with someone that knows for sure.

[mikebi]

New to this site.  cannot for the life of me find where on this forum where to ask a question other than barge in on a confersation that is already in progress.  can you help me?

[MikeSowsun]

Yes, your lens should be compatible. I doesn't make sense that your lens is not mounting properly.  

Try taking a photo of the camera and lens, showing how you try to mount it.  After you save the photo to your compiter or phone or iPad, you can then attach the photo to a post in this forum.

To post, just go to one of the board names like "Lenses" or "EOS Rebel" and you will see a box called "NEW MESSAGE" in the upper left corner.

[ebiggs1]

" I would double check with someone that knows for sure."

He doesn't know for sure. SOmetimes they do work, sometimes they don't.  And, sometimes they work but not well.

Do you have the T7i or are you thinking of buying a T7i.  If you already have it, try the lenses yourself.  You may be surprised. If you don't have a new T7i yet, buy it with new lenses.

[MikeSowsun]

Yes, try out the lenses because they might work. 

Very often the AF works fine, but the aperture only works wide open. If you try to stop down the lens, (either manually, or in an Auto mode),  it will cause an error message, or lock up the camera. 

[mikebi]

Hello.  I have a question about lense compatibility with my EOS Rebel T3i - I have a Canon Zoom Lens EF 75-300 mm f/4-5.6 III lens that I have tried to mount on the body of my EOS Rebel T3i, but the lens will not mount flush with the camera body.  I do not want to force anythng.  (1) is the lens compatible and (2) what am I doing wrong?  

Once mounted as well as possible, when used and I zoom in on an object it is blurry no matter what I do.  Can you Help?:

[RobertTheFat]

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@mikebi wrote:

Hello.  I have a question about lense compatibility with my EOS Rebel T3i - I have a Canon Zoom Lens EF 75-300 mm f/4-5.6 III lens that I have tried to mount on the body of my EOS Rebel T3i, but the lens will not mount flush with the camera body.  I do not want to force anythng.  (1) is the lens compatible and (2) what am I doing wrong?  

Once mounted as well as possible, when used and I zoom in on an object it is blurry no matter what I do.  Can you Help?:

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How long have you had the camera and the lens? Does the lens work on other cameras? Does the camera work with other lenses? If I had to guess, sight unseen, I'd suspect that the lens has been dropped and that the mounting flange got bent a little. But we really need more information about exactly what works and what doesn't.

[Mike1313]

I wound up getting an A65 instead,the deal was too good to pass up,haven't tried the lenses on it yet as I got a couple of good ones with it but thank you for the info!