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06-19-2013, 05:16 PM   #1
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Canon EoS Aperture open or closed off camera?

Hi I have a Sigma lens with an eos mount , it was supposed to be pentax but it wasn't worth sending back.
Anyway i was thinking of reverse mounting it to play with macro but the aperture looks to be at a minimum.

So heres the question is that normal? It would be a lot more use to me if it was wide open to be honest.
however i don't want to hack the lens to make it open unless of course it is a broken piece of junk.
Looks clean and tidy thou.

thanks for answering if you can

06-19-2013, 06:37 PM   #2
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I'm guessing it doesn't have an aperture ring? Many autofocus lenses will default to the minimum aperture when off camera, so tend to serve poorly as reversed macro setups. Not sure if there are any workarounds for it, but others may have some ideas...
06-19-2013, 06:43 PM   #3
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All my eos lenses are wide open unless taking a picture and open when removed from the body, but It may be possible for the lens to be stopped down with the DOF preview and then shut the camera off and remove the lens and it may stay that way, but I'm not sure. Maybe find a friend with a canon and make sure it works.
06-20-2013, 12:07 AM   #4
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I guess thats one for and one against... It is stopped down thats for sure for what that lens cost me it wouldn't be a disaster to take it apart and open the aperture as it would only be any use to me reversed.

The big problem is not knowing anyone who owns a canon film camera, being a sigma lens its likely a digital SLR will not be able to make sense of the lens.

Might have to find a dealer who has a used canon in stock.


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