I have an old Sigma Zoom lens used with a film Olympus OM10 (the lens says 'Made for Olympus). It has manual aperture control on the lens and manual focus.

Is there any point getting an adaptor for a Canon 600D? I've read that it may not work very well.


2 Answers 2


While I don't know anything about the specific lens you refer to, provided it mounts properly using the adapter, it should function fine in manual and Av modes. Olympus mounts appear to have a longer flange distance than the Canon EF mount, which means that your adapter does not need to have any extra glass. This is good as extra glass can affect image quality.

What you won't get with the lens is the ability to shoot in Tv, P or full auto modes (or any of the "creative" modes). You won't have autofocus either.

In addition, because you have to stop the lens down manually using the aperture ring, focusing can be a pain if the light isn't great, since stopping down the aperture will cut the amount of light entering the viewfinder. You might also have to use stop-down metering to get your exposure right.

Having said all that, I use an old Nikon-mount Sigma with my 30D, in low light, to do macro photography and often get great results. See below for an example of what can be done with fully manual lenses.

Finally, an OM to EF adapter seems to cost in the region of $10-$15 on EBay. I'd say it's definitely worth a punt at that price!

Butterfly Crop


The short of it is that it will work, assuming:

  1. The adapter is well made, well within the specifications for the EF/EF-S mount.
  2. The adapter isn't defective.
  3. There isn't anything sticking out the back of the lens bayonet. Some do like certain Contax Zeiss lens. Be sure to check via forums or someone who has them. Assuming you bought the lens already it's a moot point :(

I don't have a OM to EF adapter since I intend to use the OM lens for the Pen but I do have a few Contax Zeiss lens being used on a MK II. I did all of the above to make sure things do work for me.

Try to get an adapter with focus confirmation, that helps a lot when focusing manually :D


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