Very interesting, my copy which backfocuses from 10' (fine at 3ft) was always fine on a 40D.
I got a call from the Melbourne (other side of Australia almost) office of CR Kennedy regarding an e-mail I sent to Sigma regarding the issue. The e-mail was very detailed on the issue and I thought conveyed my level of technical knowledge and the degree to which I have tested this lens (two copies in fact) but obviously not.
I got a very condescending lecture on the nature of DOF with a f/1.4 lens and the fact that it's most likely my body that has an issue and blah blah learn to use a camera etc.
I then replied by describing the issue (as detailed in my e-mail) saying that it wasn't technique as a pro (who works for CRK) saw the same issue with the same two copies. Also, that it wasn't my body as I have Canon/Sigma/Tamron EF-mount lenses all of which AF perfectly... including this 50mm when closer than 10'. I also politely said that I would prefer to deal with Nick at CRK Perth since he knows what he's doing.
The guy from CRK Melbourne said he had been contacted by Sigma JP and asked to contact me with this information... Seems Sigma are still denying this is an issue and are trying to sweep it under the mat. I *still* have not seen an example of a >10' shot clearly focused on a full frame body. I would *prefer* to see a .CR2 so I can open in Zoom EX browser and confirm the appropriate focus point lit up but sigma said best they can manage is possibly some jpegs.... hmm.... of course they didn't end up providing those either.
Ubuhle wrote:
After reading through this posting, I think I will pass on the Sigma 50mm. I really love this focal length, but there just does not seem to be an excellent AF lens in this range.
Guess I will have to find a nice MF lens... perhaps the Rokkor 58mm or the Canon 45mm TS.
Yup. Or you buy the Sigma and turn the AF off, just enjoy the AF when up and close. The Sigyy50 is still the "best" 50mm I have tried thinking of the combination of resolution and contrast wide open and the bokeh. It doesn't have the best MF feeling but you it is usable.
Jonas B wrote:
Yup. Or you buy the Sigma and turn the AF off, just enjoy the AF when up and close. The Sigyy50 is still the "best" 50mm I have tried thinking of the combination of resolution and contrast wide open and the bokeh. It doesn't have the best MF feeling but you it is usable.
This is what I plan to do until CRK get back to me with a viable solution to use FTAF (full time AF, didn't know if that was already an acronym, I know FTMF is for USM haha).
thrice wrote:
I *still* have not seen an example of a >10' shot clearly focused on a full frame body. I would *prefer* to see a .CR2 so I can open in Zoom EX browser and confirm the appropriate focus point lit up but sigma said best they can manage is possibly some jpegs.
In previous post of this thread, somebody else had pasted a website link of Japanese, there are some sample photos shot by 1Ds M3 over there. Have you seen them ?
Giv3n wrote:
In previous post of this thread, somebody else had pasted a website link of Japanese, there are some sample photos shot by 1Ds M3 over there. Have you seen them ?
Sure have, none of them focused beyond 10'.
I've formally asked Sigma to provide a .CR2 from a full frame Canon body so that I can confirm that this lens is working on full frame at least for them. I doubt I'll get that though.
It's frustrating that it seems they're trying to sweep this under the rug at this point in time... Is it because they realize a recall may be necessary? They have to be aware of the flaw..
And all I want is a fully functional lens
thrice wrote:
Sigma rep named Desiree Gaige says she has a Sigma 50mm that works perfectly on the 5D in her office and says I should take my body in with my lens for calibration. No samples or proof though.
I'm sending the lens back to B&H and waiting a few months before I try again.
Ha! Maybe she's talking about my copy that they have in for repair! One can only hope...
They only had mine in for two days and it's on the way back. I will receive it next Wednesday and report here. I have a feeling the problem probably was not fixed, but we'll see. I told Desiree I have a 5D and asked her to make sure to test it on their 5D. I explained the >8ft. backfocus problem and provided four prints of test shots demonstrating the issues. Camera on a tripod with center-point focus.
If they deny there's a problem, it's going straight back to Amazon. I might try again in a few months like thrice depending on people's reports.
thrice wrote:
I've formally asked Sigma to provide a .CR2 from a full frame Canon body so that I can confirm that this lens is working on full frame at least for them. I doubt I'll get that though.
Here is an informal comparison of my 3 50's. The Sigma 50/1.4 EX DG HSM, the Asahi Pentax SMC Takumar 50/1.4 M42 and the Cosina Zeiss Planar 50/1.4 ZF.
The Sigma colour cast is much more neutral than the other two, both slightly yellow wide open. The Sigma actually captures more light, as using manual settings I needed another half stop shutter speed with the Pentax/Zeiss for same exposure. All on a tripod, no MLU but shutterspeeds at all but f/8.0 unlikely to require it. All ISO100 and with the exception of the Sigma manually focused.
Sorry about the boring subject it was just quick & nasty and I wanted to see which handled highlight definition better. If pressed I'd have to say I prefer the Pentax bokeh. The Zeiss loses wide open, noticeably, but has great highlight detail.
All 100% crops, notice the Sigma is shorter than the other two, I'd guestimate it's actually 45mm or so.
F/1.4 Sigma / Pentax / Zeiss
F/2.0 Sigma / Pentax / Zeiss
F/2.8 Sigma / Pentax / Zeiss
F/4.0 Sigma / Pentax / Zeiss
F/5.6 Sigma / Pentax / Zeiss
F/8.0 Sigma / Pentax / Zeiss
Also worth noting that until f/8.0 the Pentax trumps the Sigma on the edge crops.
Willdo. That shot looks like it's most likely focused properly. It is f/2.8 though, so might have had a little leighway. We also don't know which focus point was used and if it lit up, since it's not a cr2. Hopefully I'll get some clarity from Sigma on Monday.
thrice wrote:
Willdo. That shot looks like it's most likely focused properly. It is f/2.8 though, so might have had a little leighway. We also don't know which focus point was used and if it lit up, since it's not a cr2. Hopefully I'll get some clarity from Sigma on Monday.
Well, here's the f/1.4 shot from the same series. Evidently there's nothing wrong with this person's lens:
Interesting, I'll contact him and ask his serial number and whether he has noticed any of the issues so many of us are experiencing. Tremendous amount of DOF for a shot at f/1.4. If he actually focused on the building as it seems to be in the best focus then I'd say he has the mythical perfect FF copy haha.
Well I just got a call and apparently it's spot on on a 1Ds Mark II. So I'd say it's only 5D's and mark III's? I just got told *again* to calibrate my body though... my body is perfect, more than 1 person has this same unique issue and my other lenses from plenty of other vendors are perfect. I don't know how many times they want to blame the other gear but Sigma have lost a lot of respect in after sales service from me. So back it goes for the refund. Might also sell my 12-24, feel a little dirty using it.
Either way I'll put up with manual and keep using my Pentax, maybe I can use the money I'm refunded to fund a rokkor
thrice wrote:
Here is an informal comparison of my 3 50's. The Sigma 50/1.4 EX DG HSM, the Asahi Pentax SMC Takumar 50/1.4 M42 and the Cosina Zeiss Planar 50/1.4 ZF.(...)
That's some nice images, and a lot of them...
OT question: Is there a way to post clickable image links on this forum?
I have "tested" the Siggy 50 on my loaner 450D trying to find out about the AF issue. I found nothing new to tell you but can only confirm that the lens (adjusted by Sigma as described earlier) focuses fine up to 2 or 2.5m. From there it back focuses pretty badly.
Jonas B wrote:
OT question: Is there a way to post clickable image links on this forum?
only if they allow HTML in posts I think.
As for focusing issues on a 450D hmm I haven't tested mine on a 450, might do so before I post it back tomorrow out of curiosity.
EDIT: Had a read of your DPReview posting, very good methodical approach there! I should have taken more care with my MF tests as it appears manual focusing overcomes any issues on the 450D, but I don't have live view to help me on my 5D
I think it's quite apparent there is a serious issue with AF on this lens, on varying bodies, in varying countries but always at >=10'
thrice wrote:
EDIT: Had a read of your DPReview posting, very good methodical approach there! I should have taken more care with my MF tests as it appears manual focusing overcomes any issues on the 450D, but I don't have live view to help me on my 5D
I think it's quite apparent there is a serious issue with AF on this lens, on varying bodies, in varying countries but always at >=10'
Thank you.
I doubted the first reports as I had a front focusing problem, at all distances. After having the lens adjusted by Sigma I got the same results as other user have reported earlier.
That leaves me/us with the choice of having an auto-focusing, -aperture lens for short distances and an auto aperture manually focusing lens at "longer" distances - or make another choice. I bought the Siggy50 for a reason so I'm not delighted by the situation.
The days I owned the 5D I used the Ee-s screen and it worked pretty fine for my manual lenses. With this 450D Live View is the only option as the viewfinder screen is useless for manual focusing.
One possible upside of this lens is it might spur Canon to make a 50/1.4 II with proper USM, good peripheral brightness (no vignetting) and nicer bokeh
Haha in a testament of the pure genius at Sigma I just got an e-mail telling me the circle of confusion is determined by the pixel pitch and thus a 1Ds mkIII has shallower DOF than a 5D. Well at least now we know it's clear that their technical support don't know what they're talking about.
He also told me the AF fine tune feature on the markIII's was to compensate for the fact that all canon EOS bodies have different registration distances.... .................................................................. right. As far as specification goes, that's clearly untrue.
He then goes on to tell me to get the lens adjusted blah blah rightio... still don't have that CR2 image from Nick at CRK who told me I'd have it today.
