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Photography Question 
Alethea Hawley

Using a Sigma 'digital' lens with a Canon EOS 300

I've recently swapped my Canon Eos 10D for a film camera, a Canon EOS 300. I was using a Sigma 18-55 lense with the digital camera. When I've used it with my new film slr there are black rings around each shot, especially pronounced when I use the 18mm setting. Why is this? Is the lense made only for digital or is it the Sigma / Canon mix that's causing the problems? I assumed the lens was designed for film as it didn't operate as a 18-55mm - I had to multiply by 1.6 for the digital range. I'm assuming I need to buy a new lens but want to understand what's going on.
Thank you.

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8/9/2006 1:36:22 AM

Christopher A. Vedros
BetterPhoto Member Since: 3/14/2005
  Sorry Alethea,
The lens you are describing is designed to be used with reduced-sensor digital cameras only.

When you see the black ring around your shot, it's because the lens doesn't project a large enough image on the film to cover the entire negative. It worked with your 10D because the sensor in that camera is smaller than a frame of film.

There is no problem with using Sigma lenses on your Canon cameras. You just can't use Sigma lenses with the "DC" designation on the film camera. If you stick with lenses with the "DG" designation, they will work on both Canon bodies.

P.S. Sigma's "EX" series of lenses are their best lenses. They are well worth the extra cost. (You would still need to look for an "EX DG" lens, not an "EX DC" lens)

Chris A. Vedros

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8/9/2006 6:46:28 AM

Alethea Hawley   Thank you Chris. Much appreciated.


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8/9/2006 6:58:45 AM

Evelyn Sears
BetterPhoto Member Since: 7/12/2004
  Chris's explanation is correct. I just want to add that you may want to try selling your DC lenses on ebay. Or maybe a local camera store will buy them from you or sell them on conisgnment for you. I'm sure someone will snap them up in a hurry. That may give you some cash to put toward your new lenses. No point keeping the old ones if they aren't going to do the job.

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8/11/2006 9:37:07 AM

Alethea Hawley   Hi Evelyn, thank you. I use Ebay a fair bit and sold the lens at the weekend.

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8/15/2006 6:39:20 AM

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