p.7 #1 · Sigma 14-24mm f/2.8 DG DN first impressions
scalanc2 wrote:
Is the CA advantage due to software correction?
Both lenses have in-built CA correction applied that I can't turn off in CR. I suspect strongly it's a lens-based advantage from the Sigma rather than the correction being better. Maybe someone using C1 can confirm, as I believe the CA correction can be disabled in that software.
p.7 #2 · Sigma 14-24mm f/2.8 DG DN first impressions
goto_dengo wrote:
How does a modern 14-24, like this, compare to the Nikon 14-24, which is now more than 10 years old?
I assume the advantages at 2.8 might be significant, but much less so at e.g. 5.6?
Just curious. I'm expecting delivery of this lens tomorrow. I've been an all prime shooter since I got the A7RII when it launched, so zooms are to me a new (old) kinda thing.
It's been a long time since I used the Nikon 14-24 on Sony (42mp), but particularly in the corners I remember it being pretty poor at 14mm with lots of CA. You will see a substantial improvement with the Sigma, even at 5.6.
The Nokton 21/1.4 is on this forum probably considered pretty much as good as it currently gets in wide angle primes in relation to IQ. And as you can see from my comparison above, at 5.6 the Sigma zoom looks to be just as good.
p.7 #3 · Sigma 14-24mm f/2.8 DG DN first impressions
Here is another go at assessing wide open centeredness of my copy at 24mm in some better light, and focused slightly further out. Maybe it's a little better than than indicated by my last test on the previous page. If you have this lens, and care to assess how well it is centered at the long end in particular (where my copy at least performs worst), please feel free to share your findings.
p.s. I find it better to focus so at least one corner is sharp rather than focusing on the center of the frame as field curvature can otherwise mean none of the corners are very sharp.
p.7 #9 · Sigma 14-24mm f/2.8 DG DN first impressions
Tim's copy looks noticeably better centered at the long end than mine, but another FMer noted his copy was similar to mine. And mine was already better centered at the wide end than another sample that I had the chance to try out.
So I am seeing quite a bit of variation so far, but it's true that none of them have been terrible and likely all produce great real-world images. Maybe that's because, if Roger at lensrentals is right about the Sigma Art quality control process, bad ones would be weeded out prior to sale.
But now I've seen Tim's results, I will try to find one as good as that, as I expect it to be my main lens along with a CV21/1.4. I just hope his isn't a unicorn.
@timerickson feel free to sell it to me if you decide you don't want it
p.7 #10 · Sigma 14-24mm f/2.8 DG DN first impressions
rvh23 wrote:
Tim's copy looks noticeably better centered at the long end than mine, but another FMer noted his copy was similar to mine. And mine was already better centered at the wide end than another sample that I had the chance to try out.
So I am seeing quite a bit of variation so far, but it's true that none of them have been terrible and likely all produce great real-world images. Maybe that's because, if Roger at lensrentals is right about the Sigma Art quality control process, bad ones would be weeded out prior to sale.
But now I've seen Tim's results, I will try to find one as good as that, as I expect it to be my main lens along with a CV21/1.4. I just hope his isn't a unicorn.
I don't think it's easy to find copies like Tim's for these ultra wide zooms. I could never get perfect symmetry throughout the entire zoom range for the 12-24/4 G, 16-35/4 ZA or 16-35/2.8 GM lenses and I tried numerous copies. (Same for Canon lenses)
Usually the long end is the FL most affected. These lenses have so many elements so chances are, something won't be perfectly aligned when zooming.
Surprisingly, I received only 1 copy of the Tamron 17-28/2.8 and it's perfect from the get-go, so luck plays a role. Someone can try 10 copies and still not get a top one. It's just the reality of zoom lenses and tolerance.
p.7 #12 · Sigma 14-24mm f/2.8 DG DN first impressions
Does not look like I have a great copy, bottom left is weakest at both 14 and 24. This lens has to go on a 10 day trip with me in 10 days (OK, I really want it to) so my return window is short when I get back, hoping I don't scuff it. It may be fine for me as stars won't show bottom left in either orientation but will check again at infinity and on stars tomorrow and Saturday. Would affect resale though.
There may be some field curvature. These were taken at ~50 feet or so; MF in the center with high mag and medium peaking but the peaking vanished as I moved the shed to the corners.
p.7 #13 · Sigma 14-24mm f/2.8 DG DN first impressions
mcbroomf wrote:
There may be some field curvature. These were taken at ~50 feet or so; MF in the center with high mag and medium peaking but the peaking vanished as I moved the shed to the corners.
My copy definitely has some mild field curvature so I would suggest you focus in one corner and then assess the others. Maybe you will see an improvement in at least some of your corners.
p.7 #14 · Sigma 14-24mm f/2.8 DG DN first impressions
rvh23 wrote:
My copy definitely has some mild field curvature so I would suggest you focus in one corner and then assess the others. I suspect strongly you will see an improvement in at least some of your corners.
I would like to confirm this. My copy has no curving field at the corners (i.e. same plane with the center). My mid field has a very slight field curvature.
p.7 #15 · Sigma 14-24mm f/2.8 DG DN first impressions
Fred Miranda wrote:
I don't think it's easy to find copies like Tim's for these ultra wide zooms. I could never get perfect symmetry throughout the entire zoom range for the 12-24/4 G, 16-35/4 ZA or 16-35/2.8 GM lenses and I tried numerous copies. (Same for Canon lenses)
Usually the long end is the FL most affected. These lenses have so many elements so chances are, something won't be perfectly aligned when zooming.
Surprisingly, I received only 1 copy of the Tamron 17-28/2.8 and it's perfect from the get-go, so luck plays a role. Someone can try 10 copies and still not get a top one. It's just the reality of zoom lenses and tolerance....Show more →
Thanks Fred for the heads up on your experience with the GM in particular, which if any of those zooms should have reasonable quality control. I think I'll hang on the Sigma I have for now, while I look for an additional copy that is better at the long end, and be prepared for that to potentially be a bit of a process. The one I have fortunately is very good at 14mm, where I would be using it wide open most.
p.7 #16 · Sigma 14-24mm f/2.8 DG DN first impressions
hiepphotog wrote:
I would like to confirm this. My copy has no curving field at the corners (i.e. same plane with the center). My mid field has a very slight field curvature.
That's different to mine at the wide end where the center is a bit better when focused slightly further than the corners. Although despite that, the stars in my 14mm coma example on P2 of this thread look sharp both in the center and corners. But I also see different FC with focal length, and I'm starting to wonder whether the centering differences may be impacting my FC assessment.
In any case, I only see any of this wide open. If I stop down to F5.6, the lens is essentially flat field and delivers stunning sharpness across the whole frame and full zoom range.
Realistically, the only application I have for wide open use of this lens is astro. In that case I am extremely unlikily to print anywhere near as large as for my other landscapes, and iso noise will be a far greater limitation than some mild variation in sharpness across the frame at pixel level.
It's only because I know that it's possible that I will keep an eye out for a better-centered copy than the one I have. Not because I expect any better IQ in practical terms. But I think that's probably how many of us are on this forum.
p.7 #17 · Sigma 14-24mm f/2.8 DG DN first impressions
rvh23 wrote:
My copy definitely has some mild field curvature so I would suggest you focus in one corner and then assess the others. Maybe you will see an improvement in at least some of your corners.
p.7 #18 · Sigma 14-24mm f/2.8 DG DN first impressions
Fred Miranda wrote:
So, the field curvature is wavy?
I think that's what hiepphotog is saying about his copy, but I can't see that with mine. I see some mild outward FC at 14mm (focus at infinity), but at the longer end where my copy is less well centered, I have trouble seeing consistent FC effects.
And when stopped down to 5.6, I am very hard pressed to find any evidence of FC (or decentering) at any focal length.
p.7 #19 · Sigma 14-24mm f/2.8 DG DN first impressions
rvh23 wrote:
I think that's what hiepphotog is saying about his copy, but I can't see that with mine. I see some mild outward FC at 14mm (focus at infinity), but at the longer end where my copy is less well centered, I have trouble seeing consistent FC effects.
And when stopped down to 5.6, I am very hard pressed to find any evidence of FC (or decentering) at any focal length.
Thanks for all your testing!
I may pickup a copy and try it out. I think it should do better towards the edges compared to the new Tamron 17-28/2.8.
The Tamron does really well at center and mid-field but the corners never get really crispy even stopped down: https://www.fredmiranda.com/forum/topic/1584193/22#14953317
p.7 #20 · Sigma 14-24mm f/2.8 DG DN first impressions
I got my copy today. I did some quick tests at 14mm, 18mm, 21mm and 24mm. 14 is strong barrel distortion with moustache. 18 is less barrel distortion. 21 is hard to tell. 24 is slight pincushion. I'm not the best tester, and certainly not for distortion. I am uploading a big set of tests (2GB) onto my Google Drive. I will share my tests, including the distortion shots.
