C100: C100 & Sigma Lenses.

S

Scott Freestyle

Well-known member
I was just testing my Sigma 70-200 f2.8 OS... The autofocus only works when the lens it wide open at f2.8... close it to 3.2 and onwards and it no longer works. I have just search google for an answer and a similar question was being asked about the Sigma 35mm 1.4.. This guy seems to have the same issue. Anyone else experience this with Sigma's ?
 
Testing the lens on my mark 3 just in case it had decided to stop and no.. its perfect. Autofocus on all the lenses works fine.. better on Canon lenses than 3rd party though...
 
I have the all new sigma 35mm 1.4, the one push autofocus on C100 works occasionally with my 35mm. sometimes I have to twist the lens off and back on in order to make it work.

my other L series does not have a problem like this

and I have a MK3 too, I tested that, its perfect as you said.

Im blaming this to C100's autofocus system, its a castrated version, even worse than a T2I I bet.
 
My Tamron 17-50 f2.8 has infrequent problems with the focus and will sometimes jump to f2.8 and just not focus. My Canon 70-200 f4 L has no such problems.
 
By the sounds of it the C100 is a bit crappy for autofocusing, not realy so much a problem for us video guys, but its something that should be of note..

Cheers fella's
 
Shawnvfx said:
I have the all new sigma 35mm 1.4, the one push autofocus on C100 works occasionally with my 35mm. sometimes I have to twist the lens off and back on in order to make it work.

my other L series does not have a problem like this

and I have a MK3 too, I tested that, its perfect as you said.

Im blaming this to C100's autofocus system, its a castrated version, even worse than a T2I I bet.
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I have the old Sigma 30mm F1.4 and it seems to work fine. I'm not sure what it might be.
 
I have the last version of the 30mm f/1.4 Sigma before they redesigned it and slapped the "ART" on the end of the name. On the C100, it AFs only when wide-open. If you stop it down, it refuses to AF.

Not a huge deal for me.
 
Anyone know if the sigma primes will autofocus with the new c100 AF upgrade or is that just for canon lenses?
 
I put the Sigma 18-35 on a Canon 70D that basically has the Dual Pixel AF and it works great so I don't see why it wouldn't with the Cinema EOS cams. The new STM lenses that Canon has is built around the new AF system. I also have one the 40mm 2.8. Great little pancake and the AF is crazy fast and quieter than any other lens I have tried.
 
Just checked my Sigma 24-105 - it will only push auto focus at F4 - anything else, and it just does nothing.
 
Makes me want to stay with all Canon lenses if this is the case. I also have heard about some AF issues with cameras such as the 5D III, but I really don't have any personal info since I don't have any Sigma lenses. This would be a concern since I shoot stills as well as motion photography.
 
greenheron said:
Makes me want to stay with all Canon lenses if this is the case. I also have heard about some AF issues with cameras such as the 5D III, but I really don't have any personal info since I don't have any Sigma lenses. This would be a concern since I shoot stills as well as motion photography.
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The autofocus "works" on the 5D, it is just spotty for some lenses. The 50mm f1.4 is sometimes inaccurate (not always), which is a shame since it's really nice (the old one; new one looks even better). The 18-35mm f1.8 for whatever reason autofocuses great on my 5D but not on other cameras (APS-C), which it actually covers. Sigma autofocus on stills is just spotty, but the functionally is there.

I would be BUMMED if the 18-35mm f1.8 and Sigma 50mm (though I could lose that more easily) don't work on the C100! The 18-35mm f1.8 would make such a sick steadicam lens.
 
greenheron said:
Exactly, spotty does not work for me.
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To be fair, my 17-40mm L is spotty, too. The Sigmas are not so bad. The 18-35mm f1.8 is close... hoping it autofocuses with this upgrade as it is an amazing lens optically. Performance and "look" all in one. But for stills I do prefer Canon lenses, though the 17-55mm IS and 70-200mm f2.8 lenses are the only ones I've found really nailed it for AF. Soft spot for the 50mm f1.8, though, which is pretty darned great, too! Sometimes... The old Sigma 50mm f1.4 is frustrating. Amazing "look" and sharp, but dodgy at times. Not always. Often spot on.
 
Hi,

I bought the Sigma 18-35mm Sigma. Great lens, like it. I want to use it in my C100 and first the Push Auto Focus Button works but from one moment to the other it dosn't work anymore. I try my other lens (Canon EFS 15-85) and the Push AF works great. Does anybody know a solution ?
The lens is on AF mode :-)

regards
Paul
 
perrostar said:
Hi,

I bought the Sigma 18-35mm Sigma. Great lens, like it. I want to use it in my C100 and first the Push Auto Focus Button works but from one moment to the other it dosn't work anymore. I try my other lens (Canon EFS 15-85) and the Push AF works great. Does anybody know a solution ?
The lens is on AF mode :-)

regards
Paul
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Just out of curiosity: Did you upgrade to the latest firmware in between?
 
perrostar said:
Hi,

I bought the Sigma 18-35mm Sigma. Great lens, like it. I want to use it in my C100 and first the Push Auto Focus Button works but from one moment to the other it dosn't work anymore. I try my other lens (Canon EFS 15-85) and the Push AF works great. Does anybody know a solution ?
The lens is on AF mode :-)

regards
Paul
Click to expand...
i think it will only work with the lens wide open.
 
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