loudtiger wrote:
when i had issues with my sigma 30 on my rebel xti, they asked me to send the body in also. i didn't.
when i got it back, the lens was way worse than before.
but you would wonder, what if the next time i got a new camera? would the lens not work? what if i used a friend's camera? or if someone wanted to borrow it? it doesn't make sense to have a lens "tied" to a camera. it seems like all other canon lenses "work" on other canon cameras (to a certain extent... lol)
Well, yeah. This is what gives me the willies about Sigma. I had a Sigma 30 and a 350D once. The combo worked perfectly. Changed the body to a 30D and suddenly the Sigma stopped autofocusing anywhere near the target -- it was way off, a third of the distance or more.
I dumped the whole shebang rather than face the pain.
Glassbottle wrote:
Well, yeah. This is what gives me the willies about Sigma. I had a Sigma 30 and a 350D once. The combo worked perfectly. Changed the body to a 30D and suddenly the Sigma stopped autofocusing anywhere near the target -- it was way off, a third of the distance or more.
Reminds me of my experience with the 85L! Works like a charm on the 20D but then when I switched it to the 350D it was all over the place. Still I keep it for special occasions
The Sigma service centre did note down that I had a 5D, perhaps they will be able to calibrate to a "stock" 5D without having the body there? I know I've never had ANY focus issues with any of my other lenses, been quite lucky really.
The Sigma is a difficult lens to test: field curvature is unusually high. Any flat target tested without considerable focus bracketing will give an false impression of the lens' resolving ability.
I only have one camera body (5D) and am reluctant to send it in to Sigma for 2-3 weeks. I wonder how far they'd get with only the lens alone. In any event my replacement from Amazon comes on Wednesday. I'm pretty certain it will be date code >1002000 so we'll see if the issue has been resolved in later copies.
Steve Spencer wrote:
I went back and tried to follow autofocus issues as reported in this thread. Six people have reported fairly serious autofocus issues: Simon_k, hubsand, 05xrunner, Jonas B, badlydrawnboy, and thrice. At least four of these report really bad back focus at distances longer than 10 feet. Trumpet-guy has sent his for autofocus review and it will be great to hear back what is found. Four others haven't reported on their autofocus or at least I didn't find their reports: MichaD, perspective, martsmith42, Kjetlis. Chez_Wimpy is the only one who has reported that his autofocus works well. I apologize if I missed anybody else who posted. I would love to hear from those who haven't reported on autofocus on their lens yet. Right now it looks to me that at least a lot of the lenses have a serious autofocus issue. Let's hope it can be fixed. Perhaps Chez somehow hit the lottery, but he also may have found a work around. He reports always using AiServo and center point only. Thrice's shots looks a little better with AiServo too, so maybe this helps and if Chez's lens is a little closer to being in spec fixes issues. It will be interesting to see how all this works out. I hope people keep reporting here....Show more →
I will be getting my 50 back this week from Sigma and I will post shots of the differences. I really hope its all ready to go. from 2.5feet and closer I was very very very pleased with tis 1.4 performance and if it can do that at all distances. I will be set
Edit:::Guess I wont be able to test as soon as I thought. Sigma called and said the lens performed perfect on their 20/30/40D bodies and they have no MKII to test it with, they want me to send in my body
hubsand wrote:
The Sigma is a difficult lens to test: field curvature is unusually high. Any flat target tested without considerable focus bracketing will give an false impression of the lens' resolving ability.
I suspect this is true for close-up targets, as my testing shows that the edges
of a flat target about 2.5 meters away do not sharpen up with narrowing aperture,
even though the center is sharp. On the other hand, targets at a further distance
show nice sharp edges, even on a 5D (as evidenced by a pic that joe mama sent
me). If it's flat targets, up close, that you want to photograph, a Canon 50/1.4
or a macro lens would be preferable.
On the (very revealing) 1Ds III, field curvature manifests clearly at f1.4 at all distances – but of course especially at close up. At a distance of 2m the focal plane bulges inward about 25cm in Zone A compared to Zone C.
I am not one to normally test lenses but this one appears to be too far out of whack to be acceptable. f1.4-f2.5 are very soft and the CA is absolutely horrible, the green on the tree trunk is CA!
Am I expecting too much? What do you think?
So, I locked my camera (SD14) down on my tripod and captured all of these using the two second timer, all at ISO100, all auto focus in the centre. About ten feet away from the tree. From f1.4 and each stop all the way to f8
edwardkaraa wrote:
I find the Sigma bokeh terrible.
Are you joking?...Its obvious that the Sigma has the best bokeh of the bunch...The others have harsh bokeh which is bad bokeh and the Sigma has smooth bokeh which is always good bokeh...In fact the smoother the better
neilvan wrote:
I am not one to normally test lenses but this one appears to be too far out of whack to be acceptable. f1.4-f2.5 are very soft and the CA is absolutely horrible, the green on the tree trunk is CA!
Am I expecting too much? What do you think?
So, I locked my camera (SD14) down on my tripod and captured all of these using the two second timer, all at ISO100, all auto focus in the centre. About ten feet away from the tree. From f1.4 and each stop all the way to f8
Thanks for the samples. I've looked at the first one (f/1.4) and I'd say it's definitely misfocused -- and on a Sigma body to boot
The CA that you're seeing is actually longitudinal CA, which occurs only in OOF areas. In fact it's not particularly bad, not as compared with the longitudinal CA of the 35L. Ironically, it would go away from your area of interest if only you could get it in focus.
Alf Beharie wrote:
Are you joking?...Its obvious that the Sigma has the best bokeh of the bunch...The others have harsh bokeh which is bad bokeh and the Sigma has smooth bokeh which is always good bokeh...In fact the smoother the better
Ah, bokeh is in the eye of the beholder. The very title of this thread suggests that some people will love the Sigma bokeh, whereas others will hate it. Not everyone agrees that smooth bokeh is always good bokeh, but it is fine if that is the way you feel about it. Just let others have a different point of view. They don't have to be joking; they just might see things differently.
Wow. I wonder what the actual percentage of these lenses with AF issues is. Seems quite high from the looks of this thread. I sent my original lens back and a replacement is on the way (due to arrive Thursday). I'll report back once I've had a chance to test it.
Has anyone received their lens back from Sigma AFTER calibration yet? That's the true test. I don't mind sending it in too much if I know they can fix it.
badlydrawnboy wrote:
Wow. I wonder what the actual percentage of these lenses with AF issues is. Seems quite high from the looks of this thread. I sent my original lens back and a replacement is on the way (due to arrive Thursday). I'll report back once I've had a chance to test it.
Has anyone received their lens back from Sigma AFTER calibration yet? That's the true test. I don't mind sending it in too much if I know they can fix it.
I sent mine in for calibration but they said it showed no back focus on their 20/30/40D and they wanted me to send my body they have no 1D's to test with
dougjk wrote:
I don't believe the F-mount version is available yet. I haven't seen a thread in the Nikon forum, or at dpreview. B&H is accepting orders but doesn't have any, nor have I seen it available anywhere else.
A couple of days after hubsand started this thread I asked my (Sydney) dealer to check with the Australian Sigma distributor about availability of the Nikon version of this lens. The distributor's representative told him that it would be six to eight weeks before they had stocks of the F-mount lenses.
When I voiced my surprise and disappointment, the dealer told me it was not at all unusual for the Canon mount version of third party lenses to be available a month or two ahead of the Nikon version. But as soon as it's in stock I expect I'll be placing an order.
asabet wrote:
I'm curious as to which part has you thinking about the lens again.
Initially I didn't like the imperfect, too smooth bokeh in Mark's bokeh comparison. Then I saw the sharpness at f1.4, which is much more important than sub-optimal bokeh, so I changed my mind and decided I would get one. Then I saw loads of people complaining about autofocus so I've gone cold again. However, unreliable af isn't always a deal breaker for me. After all, I love my Rokkor, and many other manual focus lenses, so I'm cold, but still not certain. I hope that seems rational!
