Canon 17-85 Lens with Rebel XTI Camera

Question edited for clarity.

You get the Sigma lens for the camera in Canon fit.

https://www.google.com/search?q=sigma+lens+af+75-300+for+canon+rebel+xti

Can you use Sigma lenses on Canon cameras?
Since Sigma lenses are made to be fully compatible with Canon cameras, they are backwards-compatible. This means that you can use a Sigma lens on a Canon DSLR camera. Similarly, the Sigma cameras are backwards-compatible with Canon lenses. Macro adapter loses the AF feature.

https://www.google.com/search?q=sigma+lens+af+75-300+mount+adapter+ring+for+canon+rebel+xti

Since you already have a Quantaray lens, you should know that Quantaray makes lenses with a variety of mounts. A lens with a Pentax mount won't fit a Canon camera, for example. As long as you get the lens with a Canon mount it will fit the XTi just fine.

Make sure both the lens and the camera are switched to af (auto focus). If that doesn't work remove the lens and replace it to make sure it is mounted properly. You can also check the camera with a different lens to make sure it isn't a problem with the settings on the camera. If all of that fails take it to a camera or electronics store that does service work to make sure it hasn't been damaged.

If the lens has a Nikon mount (as you imply in the post), then no, it will not fit. If it has a Canon mount, then yes, it will work fine on your Canon Rebel.

I have the canon 70 -300 sitting right here beside me on my XTi, it also fits my XSi and all my EOS mount film bodies. one thing about canon EOS lenses and bodies: They fit and work together. Yes there are cheaper lenses, but I just answered another question on this website from somebody who has a 3rd party lens (and a high quality lens ta-boot) that will not work on his canon. This is typical of canon. They do not release all of their codes to 3rd party manufactures. Your friend just bought a premium camera, do not let him put a lesser lens on the camera, he will not be happy and the savings will not be that significant to make up the difference...

Try in reset the camera to factory settings.

If still you have a problem, then try with a different lens.


Best regards,

Take the lens off the camera and look through the lens. Is there anything obstructing the light?
Now have a look inside the camera body. Same thing, anything there that looks like it shouldn't be? If look up into the cavity you should be able to see the focussing scren clearly - any obstructions there?
Finally, with the lens off, switch on the camera and go through the menu until you find the sensor cleaning option. Select this. The internal shutter will open and allow you to see the CCD sensor. Have a look and make sure it is also free from obstruction.
You will need to switch the camera off to release the shutter.
Put everything back together and check the pictures again.
If still no joy, then it sounds like the CCD sensor is faulty and the camera needs a repair from an authorised Canon repair centre.

Sounds like your camera and your lens aren't communicating. Have you tried cleaning the contacts on the camera and the lens mount?

I have a Rebel XTi and take professional images. It could be that your lens isn't as sharp as it should be or your sharpness settings in the camera are set low.

If the camera does the same without the lens mounted, it's probably a defective release switch. It'll have to be replaced by a repair shop for around $130.