Yes, I also did a controlled test on a tripod (I'm away from home this weekend, will post them when I return). I used a large can of soup as the object of focus and only the center point. At distances under 10 feet, the focus on the can was perfect. At longer distances it completely misses focus on the can, even though the can is still larger than the center focus point.
This is a real issue with at least some of the 50/1.4s out there. I'm glad Chez Wimpy got a good copy, because that means they exist and it's not a design issue that can't be fixed. It bodes well for calibration.
Thanks for the post. Now to find one to purchase. It seems to me the Sigma is a head and shoulders better than the rest. I just love the smoothness and the sharpness, what a great lens.
thrice wrote:
Yeah I used a tripod I have a vague idea what I'm doing. Every shot was on a tripod, and the camera indicated the spraycan as the activated focus point using the centre focus point activated and the secondary (invisible) focus points disabled in custom functions. Hang on one moment and I'll do a definitive test for you, also on a tripod.
A colleague at work has a friend at the repair centre in my city who can get my lens calibrated, not cheap, but much cheaper than a new lens. Incidentally the guy @ the repair centre has one on loan and is having issues focusing closer than 10' on the EOS 20D, he is an accredited and qualified professional photographer....Show more →
Thrice, I did't mean to put your skills to question and I did expect you to use the tripod. But even when using a tripod, things like mirror slap etc can cause unwanted blur, in which case the longer exposures could come out better.
All this aside, when looking at the amounted evidence I am also convinced of the problems of this first batch
I look forward to going out and shooting with this lens tomorrow, I'll just MF distant objects.
As a totally off-topic question does anyone know if the Canon Ee-S screen for the 5D shows DOF better than the Haoda-fu screen with split prism and microprism collar? I ask because I own the Haoda fu screen and it's great for architectural stuff but not very good for portraits.
Am I allowed to change my mind about getting this lens again?
Thanks everyone for sharing this info - this is a great example of why this forum rocks. Good knowledge and experience kindly shared.
Shall we head over to the Nikon forum and see if the F version has the same problem? To me it looks like it might be an EOS protocol problem. Sigma have to reverse engineer it, remember.
brainiac wrote:
Am I allowed to change my mind about getting this lens again?
Thanks everyone for sharing this info - this is a great example of why this forum rocks. Good knowledge and experience kindly shared.
Shall we head over to the Nikon forum and see if the F version has the same problem? To me it looks like it might be an EOS protocol problem. Sigma have to reverse engineer it, remember.
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.
I've been watching these threads because I'm contemplating getting the lens for my D40, but the priority level is fairly low and I believe I'll wait a while to see if a Nikkor AF-S 50mm becomes available.
I spoke to Sigma UK a few days ago who promised they could fix it painlessly: if they're as good as their word, then AF gremlins won't be a problem once it's been on an extra trip to Sigma. They prefer to calibrate it to a specific camera body where possible.
I'm happy to hear that. Did they listen to your explanation of the problem and then assure you they could fix it?
Sigma USA also told me they'd like me to send in the camera body as well so they can calibrate the lens to the body. At that point I wasn't as clear as I am now about what specifically the problem was, so I didn't go into detail and didn't ask them directly whether they could fix it. I plan to tomorrow morning, though.
Hard to argue with that test Thrice. Joe Mama was shooting around with the Canon 50L and Sigma 50/1.4 on a 5D and felt that the 50L was giving him better results. Then he did a close range bookcase test, and the Sigma 50 blew him away with its detail rendered at f/1.4. I suspect that his copy was similar to yours, performing properly only at close range. He couldn't do more definitive testing though, because his 5D suddenly broke.
Andi Dietrich wrote:
You missed the point.
we have no idea how the full image looks like, where the focus sits, how much the blobs are out of focus, the distance to the background, the scale of the image
yeah as shown i WAY prefer the sigma bokeh, but how do we know it focused on the same plane as the others and the spots shown simply are much more OOF than are in the other lenses or maybe they are from the far corners and the sigma has large field curvature putting the corners much farther out.
If the affect is real then great, but maybe it's not.
Mine has gone back to B&H and I'm getting another copy from Amazon. They ship to me for free and have a 30-day return policy. If this copy exhibits the same problem, I'll send it right away to Sigma for calibration and I should get it back still well within my return window to evaluate whether Sigma was able to fix it. I'll keep you posted.
thrice wrote:
Incidentally the guy @ the repair centre has one on loan and is having issues focusing closer than 10' on the EOS 20D, he is an accredited and qualified professional photographer.
Ah, a fellow 20D user... grasping at straws here but, anyone else with a 20D who doesn't get backfocus?
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)
At the Sigma service centre today the boss said it was likely just a buggy firmware and if Sigma are aware of the issue they would have issued an updated firmware which he'll wack on the lens then give it a test for me. Should have it back in 2 weeks. I'm missing it already
@ Chez Whimpy you may find that he just wasn't used to f/1.4 on the stock screen and was testing the lens at the football so probably just missed a lot of shots closer than 10' due to DOF. Maybe 20D's are ok, but I have a feeling <1002000 serial'd lenses might have the old firmware with the >10' bug.
Even Canon will often have you send your camera in with the lenses for "calibration". I think this is at least as much a Canon body/lens AF issue, when using fast lenses, as it is a Sigma issue.
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)
I have a vague idea what I'm doing. Every shot was on a tripod, and the camera indicated the spraycan as the activated focus point using the centre focus point activated and the secondary (invisible) focus points disabled in custom functions. Hang on one moment and I'll do a definitive test for you, also on a tripod.
