brainiac wrote:
We have to be careful about our expectations here. (...)
In other words, at f1.2 you need to cut the lens a bit of slack, and the shorter the focal length, the more slack you need to cut it.
Oh, I gave it a bit of slack, having put not more but USD 900 worth of expectations to this USD 1.300 lens. (And the focus shift was easy to identify, and all this was on my 5D which had no problems focusing the 35L, EF50 or EF85/1.8 at any distances, and I'll try to keep cool when trying the Siggy50 ).
hubsand wrote:
I spent a happy/sad 30 minutes calibrating all my primes when I got the 1Ds III; most were OK: the 135L was spot on; the 24L and 85L needed a bit of help (both front-focusing), and this loan 50L needs +7 to get it right, but the Sigma is beyond help:maxed out to +20 it's still half an inch wrong at short range.
A QC issue, perhaps? Do you think returning it and getting another sample would help?
Lotusm50 wrote:
A QC issue, perhaps? Do you think returning it and getting another sample would help?
thats a waste..by the time you go through the return sending back. you could just send to sigma and have them calibrate it to specs. then i know it will be how it should. no reason to send it back and give someone else a bad copy.
I shoot with a 1D MKII
05xrunner wrote:
thats a waste..by the time you go through the return sending back. you could just send to sigma and have them calibrate it to specs. then i know it will be how it should. no reason to send it back and give someone else a bad copy.
I shoot with a 1D MKII
The problem with this, though, is that if you return it and have it calibrated and you still have focus issues - then what? You've lost the chance to return the lens for a refund or exchange. This is what concerns me. What if Braniac is correct and the problem is not just with the lens but how the lens and certain camera bodies communicate?
OK, I'll admit that I don't expect anything close to perfection from AF anymore.
I never have used a 1DIIn, which most have found to be superb in this regard,
but with a 30D, I focus-bracket liberally. If you are looking for extremely accurate
focusing on most of the cheaper Canon bodies, I think you'll be disappointed. I know
I am, but I've learned to live with it.
That said, it could very well be that the Sigma has issues in this regard. But even if it does,
I'll be happy to own a copy, since most of my shooting easily accomodates manual focus.
I just got mine today. First impressions: like everyone says, it's a solid hunk of glass and the build quality is excellent. A bit bigger than I'd like but feels good in the hand and balanced on a 5D. As everyone has said the contrast, color and edge-to-edge performance are excellent.
As for the AF... I haven't done any "scientific" tests yet, but in normal shooting I am somewhat disappointed with its accuracy. It seems that the focus is accurate only about 50% of the time using center-point AF-S.
Next step is to break out the focus chart. However, it doesn't seem like my copy isn't capable of focusing correctly (i.e. back or front focus problem); but it does seem like it doesn't focus correctly about half of the time.
Here's one that did focus as expected (no sharpening; RAW converted in Lightroom):
mine was almost perfect focus from about 3feet and closer. but as you got further out the back focus really showed and at 6-10feet it was WAY off..I think ther eis alot of this..maybe we found a flaw and sigma will be quick to fix it. Mine is on its way to sigma now and they said i would have it back by Next week for an event I have next sat.
Is that a photo of your dog, or is that the Sigma technician would designed the 50's AF, hiding from his boss?
sorry...that was a stupid joke.
I still think this is a good lens. It just needs a little fix. Shots I got wide open wher every sharp when I was close. once its fixed I bet this lens is going to kick serious ass
That dog might be the one who designed the Canon AF system. The Sigma's don't have such problems with other camera makers. Even Canon lenses need to be "adjusted".
Thanks for the tip. Anyone know anything about the C.R.I.S. authorized service center in Arizona? I'm in CA and it would be cheaper and faster for me to ship it there.
badlydrawnboy wrote:
Thanks for the tip. Anyone know anything about the C.R.I.S. authorized service center in Arizona? I'm in CA and it would be cheaper and faster for me to ship it there.
I would send it to Sigma in NY and no where else. With the misfocusing Sigma 30/1.4 copies, that seemed to be the most successful approach. The argument for exchanging rather than sending for repair is a valid one - there may be some irreparable copies out there, and no one wants to be stuck with a lemon. However, assuming that one's copy can be repaired, Sigma service is a better bet than exchange for a rapid and favorable outcome. Exchange may bring a second suboptimal copy, whereas service generally does the trick. I say this based on my own experience with the Sigma 30 (two bad copies in a row, the second of which was quickly sorted out by Sigma in NY) as well as reading the reports of many others.
asabet wrote:
The argument for exchanging rather than sending for repair is a valid one - there may be some irreparable copies out there, and no one wants to be stuck with a lemon.
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.
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'm not familiar with the lemon laws. Could you elaborate?
And what about shipping costs? Does Sigma reimburse me for my cost to ship the lens to them for repair? It doesn't seem fair that I should pay $15 on top of what I already spent just to get a product that should have worked correctly in the first place.
05xrunner wrote:
mine was almost perfect focus from about 3feet and closer. but as you got further out the back focus really showed and at 6-10feet it was WAY off..I think ther eis alot of this..maybe we found a flaw and sigma will be quick to fix it.
Uncanny. That's exactly what happened to my Sigma 30/1.4 a couple of years ago, when I changed Canon bodies.
I "upgraded" to a 30D and, for the first time, the lens suddenly began exhibiting the behaviour you describe -- ok focus at very close range, way-off focus as you got further away.
My lens was never fixed because I promptly dumped it, the body and a Sigma 10-20 as trade-ins on a 5D.
But I'm wondering if there may be some recurring similar kind of curious incompatibility between the firmware in certain Canon bodies and certain Sigma lenses.
I'm sad to hear of these misfocusing reports about the Sigma 50/1.4 because it would otherwise fill a gap in my gear perfectly. That gap is inadequately occupied by my unloved EF 50/1.4, a lens I would probably use much of the time if I liked the look of the pictures it takes. And I love the look of the Sigma as seen so far.
).