I don't want to be an apologist for the Sigma 50/1.4 but the way I look at it, there
aren't many times I'd use it that required great autofocus performance. I autofocus
then tweak the focus manually. But that's what I do with my EF 50/1.4 also.
It would be great if it worked superbly right out of the box, which it should if
Sigma hopes to take much market share from Canon; but, even if there are
quirks to work around it is so good wide open and up close that it's worth it to
me to keep it.
Now, when I get mine back from joe mama over at dpreview I'll check its
autofocus more carefully.
Chez Wimpy wrote:
so we pass it on to the next sucker...
The lemon laws in America exist so that you DO have recourse if Sigma themselves can't sort it out after three tries. Cherry picking only contributes to the "reputation" and increases the chances of getting stuck with a returned "bad copy" your first time round.
I personally would send my lens to Sigma in NY for repair. My point was that I couldn't blame someone else for doing the exchange. Relying on lemon laws in the unlikely case of an irreparable lens is not an attractive option IMO.
Frankly, if I knew I would get a copy without focusing issues I would return it to B&H. I don't think customers should be responsible for jumping through hoops to get a working copy of a product they've bought. OTOH, I'm not at all confident that another sample of the Sigma would be any better than the one I have now.
Ideally I would have bought it from Amazon, who has a 30-day return policy. Plenty of time to send it to Sigma and get it back and make sure the calibration worked. B&H's policy is 15 days, so that's a bit tight.
Talked to Sigma. They don't reimburse the customer for shipping. That's poor service. I buy a new lens, then have to pay a premium just to get it to work right? Doesn't seem right.
badlydrawnboy wrote:
Talked to Sigma. They don't reimburse the customer for shipping. That's poor service....
BDB,
Did they say anything, in general, about the problem? For instance, were they confident that any lens with this problem can me made 100% correct in every way, or did they give the standard "we have to see it first" line?
Here's an interesting comparison on a 5D between the Sigma at f/2.8 and what seems like a sub-par copy of the 24-70L at the same aperture. Looks as if the 24-70 pic has undergone no postprocessing. If the same is true of the Sigma image, then wow.
I will report when i get my 50 back next week from sigma about my back focus issue.
I have to say close up shots where the backfocus wasnt really present and I shot wide open at 1.4 it was crazy sharp and the lens seem to be a killer of a lens. Now when i get it back and the AF is all taken care of and how sharp it is..its gonna be hard to beat with its price.
Wide open, and the front of the scooter is as sharp as you could wish for.
But what excites me about this picture is the complete lack of colour fringing around the edges of the bright metal, and the lack of longitudinal chromatic aberration -- there's no green and magenta colour shifts in the OOF areas.
Compared with the 35L and the 85/1.8 on that basis, this lens looks like it's shaping up to be a marvel. I'm starting to suspect it has fewer optical disorders than the 85L, too, even if it doesn't have the charm or the cachet.
Glassbottle wrote:
Here's an interesting comparison on a 5D between the Sigma at f/2.8 and what seems like a sub-par copy of the 24-70L at the same aperture. Looks as if the 24-70 pic has undergone no postprocessing. If the same is true of the Sigma image, then wow.
Interesting comparison. This photo from that link demonstrates the interesting bokeh characteristics of the Sigma. The foreground bokeh is harsh with sharp edges and doubling of elements, whereas the background elements are very soft. This speaks for significant residual spherical aberration, but it's hard to reconcile that with the impressive apparent detail and contrast of the in-focus areas in some of the samples from this lens.
I wonder to what extent some of these early reports of focus issues are related to focus shift. It would be interesting to know whether misfocus is occurring only at specific f-stops. For example, the C-Sonnar 50/1.5 is optimized for focusing properly at f/2.8 but displays focus shift at f/1.5. Meanwhile Zeiss offers a free service to optimize for least focus shift at f/1.5.
Did they say anything, in general, about the problem? For instance, were they confident that any lens with this problem can me made 100% correct in every way, or did they give the standard "we have to see it first" line?
No. I should hav been more clear - I actually didn't speak to anyone, I emailed them. They refused to reimburse for my expense to ship to them, saying that no one in the industry does that for warranty repair so they don't either. Not a good reason, IMO - but there it is.
I doubt they would answer your question over the phone with anything other than "send it in and we'll take a look."
I have a (relatively) OT question for those of you who have used both the Sigma 50/1.4 and the Canon 35L. Which is sharper at 1.4? How do they compare overall?
Jeez, if that's a routine problem with these lenses, it's not just a little flaw, it's criminal stupidity on Sigma's part. I'm very interested in hearing from others about this autofocus bug (or the lack of it). I really want one of these lenses but my presbyopic middle-aged eyes don't want to have to rely on manual focus, thank you.
I received mine yesterday and it has a pretty bad front focus at all distances @ 1.4. Once I stop down a bit I get a nice sharp image, but thats not the point of this lens!
I called up Sigma today and they said the lens isn't compatible with my camera body(Canon D60). He said that its very old and that Canon has changed the way their focus systems work.
I wonder why my 17-40L and 70-200L focus properly? :-) (I put the 17-40L through the focus test last night and I'll do the 70-200 today)
I've got a friend with a 40D coming over tonight to try it out. I'll post the results tonight.
If the 50 1.4 ends up being a dud, I'm not sure which path I'll take. I work in NYC and can just return it to B&H and get another or send it back to Sigma. Sigma said it would take 1-3 weeks to get back.
They also said I should send in my D60 so they can calibrate the lens to work with it. I hesitated at that thought, because if my D60 is the malfunctioning part when I finally upgrade later this year, the lens won't work.
I guess its possible I haven't noticed the front focus on the D60 since I never had a lens that produced such a shallow depth of field.
