06-20-2014, 08:24 AM
Well, I can only comment based on what we are seeing here ...
next PZ lens test report: Sigma 50mm f/1.4 DG HSM | A on APS-C
06-20-2014, 08:24 AM
Well, I can only comment based on what we are seeing here ...
06-20-2014, 08:57 AM
Me too. And I see my Sigma Art lenses not as worse than the Nikkors. Nor do I see a lot of sample variation, when lensrentals is testing a batch of lenses.
Maybe you're talking about Sigma lenses in general, including all series before they shifted into this Art / Contemporary / Sports categories.
I'd like also to remind the difference on price tags. Don't know how, but Sigma was not expected to be that good on those low prices and I think we should demand at first the high optical quality from the genuine manufacturers and the possibility of fine tuning a lot more than with conventional lenses, as there's always a difference between AF modules from body to body. Best would be to get HR mirrorless with competing AF, but until that becomes reality I do prefer the Sigma concept and quality.
And even afterwards. Why pay for a 35/1.4 nearly double the price? And get lower sharpness wide open? I hope I overcome the impulse of defending Sigma soon, as everybody can believe whatever he wants. My experience with those lenses is overwhelmingly positive. If others still think Sigma remains as low cost, low quality manufacturer, fine.
06-20-2014, 09:02 AM
The 24-104 Art was completely off, for instance. Not a big deal with the USB dock though.
06-20-2014, 10:07 AM
The 24-105, as I know mine, was not off. But is showing itself as 105/2.8 to my D800, after attaching both lenses. Having both lenses, I'm in a sort of dilemma as both need different AFMA. Deleting the 105 from the AFMA register, the Sigma shows up as 24-105/4. Re-attaching the 105 again and the 25-105 is gone again and both lenses use the same name. That's the only Sigma behaving this way, all others are shown correctly. As an answer to Studor13’s question, the 50/1.4 is showing itself correctly, but I don't know what would happen with two 50/1.4s? Only thing is, I can't imagine a reason for having two
So far, Sigma is not offering a firmware update to fix this and worse, Sigma Germany wasn't even reacting. Sigma Japan doesn't show a contact address. I've no idea, if Sigma Japan is aware of this case.
The dock's nice although the way the adjustments can be done is not the most elegant. But once it's done, the lens is rewarding the owner with pretty good results. Other lenses will also have some kind of adjustment possibilities but not to the owner. And I'm not fully convinced, the owner always knows better than the service centre how to adjust... I don't fully understand why on different.distances different adjustments are necessary, but I can see they are. I'd love to have a perfect lens out of the box, but even car seats need to be adjusted...
06-20-2014, 10:18 AM
My Sigma 50-500mm and the Sigma 105 Macro do not differentiate themselves as regard to AF adjustment, I'm not sure as to whether it's Sigma or Pentax K5 (my DSLR) which is the problem, I just write it down on a piece of card and do my best to remember to change the settings manually when changing lenses.
I think it's all down to incomplete lens identity, I don't think OEMs want to make it easy for third party lens manufactures to be able to give the whole package.
06-20-2014, 11:35 AM
I got the Sigma 50 Art not long ago. On my first test out, the AF seemed a bit hit and miss and I realised the body AFMA was set to +17! The lens shows as a 50mm on the body, and I think since I used the Zeiss 50 Makro before, it was using the value from that. Even though the Zeiss was a MF lens, I had to set the AFMA to get the focus assist to work accurately.
Since then I ran FoCal on it, and that came up with a suggested value of -4 (at body), which makes me surprised anything was in focus at the previous setting of +17. I haven't yet tried setting it using the lens dock.
The recent versions of FoCal include analysing the RGB channels separately. The Sigma showed red and green to be close to each other, but the blue channel was further away. This may be a way to look at longitudinal CA effects. I was a bit surprised at blue being the odd one out here, as on other lenses I'm fairly sure (subjectively) that the red is off compared to green+blue.
<a class="bbc_url" href="http://snowporing.deviantart.com/">dA</a> Canon 7D2, 7D, 5D2, 600D, 450D, 300D IR modified, 1D, EF-S 10-18, 15-85, EF 35/2, 85/1.8, 135/2, 70-300L, 100-400L, MP-E65, Zeiss 2/50, Sigma 150 macro, 120-300/2.8, Samyang 8mm fisheye, Olympus E-P1, Panasonic 20/1.7, Sony HX9V, Fuji X100.
06-20-2014, 02:16 PM
Quote:My Sigma 50-500mm and the Sigma 105 Macro do not differentiate themselves as regard to AF adjustment, I'm not sure as to whether it's Sigma or Pentax K5 (my DSLR) which is the problem, I just write it down on a piece of card and do my best to remember to change the settings manually when changing lenses.
I don't recall on the K-m and K-x I had before if there was any AFMA possible, but the K-5 clearly is upper class Pentax. Are the Pentax lenses recognised differently? Anyway, I had some time consuming support queries with the bodies and a Tamron 17-50/2.8 and am happy to got rid of all that. On the Nikon side, however, there's AFMA from D7000 and higher and I guess, up to 20 lenses are supported.
Popo, now you got me interested in FoCal. I should've checked before buying focus tune and the LensAlign target as Focal appears to be a bit more comfortable. Thanks.
06-20-2014, 08:10 PM
Quote:I don't recall on the K-m and K-x I had before if there was any AFMA possible, but the K-5 clearly is upper class Pentax. Are the Pentax lenses recognised differently? Anyway, I had some time consuming support queries with the bodies and a Tamron 17-50/2.8 and am happy to got rid of all that. On the Nikon side, however, there's AFMA from D7000 and higher and I guess, up to 20 lenses are supported.Pentax lenses are fully recognized, Sigma seem to fit into categories, for example, my Sigma 50-150mm F2.8 posts itself as the 70-200 F2.8, other zooms just show the focal length used. I have read around that Pentax won't allow third party manufacturers the use of their full codings, so when it's a question of lens IDs, AF adjustments can get exchanged. Keeping a list is therefore beneficial!
06-21-2014, 12:49 AM
Quote:Me too. And I see my Sigma Art lenses not as worse than the Nikkors. Nor do I see a lot of sample variation, when lensrentals is testing a batch of lenses.
Sigma has considerably more variance than canon, at least. 35L varied 7.32% across tested copies, and 35A varied 12.86%... over 50% more. However, the average 35A is indeed better than the average 35L... though less than people on the internet would want you to think.
Scythels, you're right, especially with the fact that the worst Sigmas are better than the best Canons. Okay, you said "However, the average 35A is indeed better than the average 35L" and that was 35/1.4 and here are the data of 3 different 50/1.4 (/1.2 for Canon? I don't know the meaning of 50L)
Source: Lensrentals.com, another Explanation of MTF
Now, take the price (it was Canon 50/1.2L, so that's a bit unfair). Shouldn't it be the other way round? And Nikon would range even lower with their 58/1.4, at least wide open.
Also, I was wrong - this variance doesn't say anything about AF variation we were discussing about. A lens could be excellent and the AF totally sucking at the same time (like the Otus sorry, couldn't resist). And the fact, some Sigma lenses appear to introduce themselves as something else to the camera is also a bit annoying. But less annoying than the AF variation of the camera/lens system itself and this means both manufacturers - even Nikon body behind a Nikon lens isn't better.
Like Toni-a said, what good is an excellent lens for, if the AF misses? Question remains, is that the fault of the lens or the AF system should be blamed?
Well, if people buy the Otus and know there will never be an AF to complain about because there's just no one, and the "next best" lens to the 50/1.4 Art might have better AF but is in average say 10% less sharp at 70-100% more money to pay for - it has to be a hell of superprecise, always reliable and fast AF to justify the diff.
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