[gawan]

Sigma 10-20mm f4-5.6 EX DC HSM Lens Review: 1. Introduction: Digital Photography Review

"So overall the Sigma 10-20mm F4-5.6 EX DC HSM is a solid, well-built lens with good operational characteristics.."

[kenyee]

but the center sharpness of the Tamron 10-24 is better. Guess it was time for Sigma to redesign it...

[k100d]

they are, the 10-20 3.5

[axl]

quite different from photozone.de review!! and from many other reviews I've read about this lens so far. Mainly because many others suggest that 10-20 is sharpest towards the wide end, not the other way around...
BR

[RBellavance]

quite different from photozone.de review!! and from many other reviews I've read about this lens so far. Mainly because many others suggest that 10-20 is sharpest towards the wide end, not the other way around...

I suspect it's the (in)famous Sigma sample variation at work.

[jamesm007]

I suspect a poor copy as well. My Sigma 10-20mm is at its best 12-20mm, sharp and I mean tack sharp corner to corner f5.6 -f8. At 10mm you do need to go to f8 to be tack sharp corner to corner but unlike their copy mine gets better going from 10mm to 16mm, it drops just a tad at 20mm. Overall mine behaves like the review from Photozone or SLRgear. They says its very good. If your in the market for a lens in the range don't ever count this lens out. Believe me and others this lens performs well. The distortion is low, flat as a board at 12mm, at 10mm there is distortion in the corners the a human would have a hard time removing but PTlens takes it out perfectly, it operates in 3 dimensions versus 2 that most PP programs allow a human to try. The result is flat as a board pics from 10mm up. This review is the opposite experience of what I have with it. And why would I lie, if it was no good it would not have such a huge fan base, the Sigma 10-20mm is real good. If you get a good copy, which is most of the time, but not all.

[yeedub]

So PTLens can fix the distortion well? I've always wondered about the distortion of this lens since the majority of it is in the extreme borders only.

[Sean Nelson]

I suspect a poor copy as well.

The DPR review noted the strong curvature of field and that they ran their tests with the lens focused on the middle periphery rather than the centre of the frame in order to get the most even performance. That may be where the some of the differences in the results come from.

[jamesm007]

So PTLens can fix the distortion well? I've always wondered about the distortion of this lens since the majority of it is in the extreme borders only.

For my copy all of it is in the extreme borders and less than 12mm. At 12mm and up there is no need at all for any distortion correction. I really love that part, having been use to zooms in the 17-## range that had plenty of barrel distortion at 17mm. Its really nice to take a pic at 12mm, 16mm, or 20mm and have them flat.

Now the distortion at 10mm is at the deep corners/borders only so even there with most scenes of outdoor type its nothing of concern. but at times it can cause an un-desirable affect on the pic, especially close up architectural type shots. Moreover most PP programs of any cost can only do corrections in one (maybe 2 but not PS) dimensions. PTlens works in 3 dimensions and can much more accurately and throughly correct complex distortion such as with the Sigma 10-20mm at 10mm. It comes pre-calibrated for almost every lens out today, and you need do nothing but push a button. I wish I knew of another free program to speak of, but I don't.


Below is a pic I took today of a brick wall at 10mm from ~1m away. First as-is, second with PTlens. You can imagine what it does with regular pics, makes them flat as a board it does; however I notice a very small crop of about 1-2% of the frame to do it. With most lens it does not have to do that. But it gets the job done, good enough I would say. I have read its based on another program that does corrections in 3 dimensions and the author of PTlens just automated that program to read the EXIF of lens. It then applies the pre-made calibrations from the author of almost 2600 lens, so at least he does work for that money. Nothing wrong with that. But again, I know lots of people only believe in free downloads. As a programmer I don't.

BTW the bottom right is worse than I usually see, IMO it is because I was hand holding the camera/lens and was not perpendicular to the wall.

[pcarfan]

I tried this PTlens for some of my images with the sigma 10-20, and I am not satisfied at all. The only distortions that bother me are with vertical lines at distances, and I tried two images with severe distortion, PTlens pretty much did nothing to these real life sample. It only straightened the edges, which never really bothered me.

Before:


Corrected


Before:


Corrected:


PS: THIS IS CORRECTED AND CROPPED IN CS2

[jesalonen]

Photography Monthly (April 2009) had a head-to-head test of three independent maker's wide-angle zooms (Tamron 10-24, Sigma 10-20 and Tokina 12-24). Tamron was best regarding the flare control, Tokina came out on top for vignetting and Sigma's built quality was the best on test. Editor's choice was Sigma, which "offers robust built quality and an impressive optical performance across its zoom range".

In Practical Photography (April 2009) landscape photographer Charlie Waite (ever heard of him?) had Tamron 10-24, Nikon 12-24, Canon 10-22 an Sigma 10-20 on test. All lenses were equally sharp at f22, Tamron having the best edge definition. At f3.5 Tamron was very poor, and Sigma was slightly outperformed by Canon and Nikon. Distortion was quite the same on all lenses, Tamron had abit more barrel distortion. Best buy was awarded for Sigma, being a solidly built, good allroud performer at reasonable price.

I am a happy user, too. There's much debate of Sigma quality control issues, but I have to say that I've owned at least 20 different Sigma lenses without having one bad copy. And, it should be remembered that Canon and Nikon (perhaps even Pentax!) has bads copies, too.

[MoiVous]

Gosh I'm glad to hear you guys say what a good lens this is. I first tried this lens out a couple of months back with one of our Social Group (thanks Tas) and loved it.

I've also read lots of reviews about it, compared it to the Tamron 10-24 on DPR (used their test tool for that) and was half tempted to get that lens. But in the end felt this was the better bang for buck (it is going up in price in Oz shortly) so ordered it on Friday.

Can't wait to try it out - and the guy in the shop assured me that if it plays up a replacement will be available straight away. I've read lots about bad copies of the lens, which also scares me a bit. But this bit of insurance from a local shop has convinced me.

Has anyone got any suggestions for lens filters (I know thats a contentious issue - to use or not to use.....that is the question ) - I've had Cokin filters suggested by some, and a Hoya Pro by other. Anyone care to comment?

I've got to wait a couple of weeks as its part of a duty free purchase before an O/S trip - but it should be a welcome addition to the kit bag!

Thanks for sharing your experience, and to all the reviewers on the Lens Review parts of the forum too.

[jesalonen]

Hi Chris,

I have a Hoya Pro1 Digital protector and Hoya Pro1 Digital pl Cir, haven't noticed any vignetting. I think it' s safest to be on the slim side,

Jari

[MoiVous]

Hi Chris,

I have a Hoya Pro1 Digital protector and Hoya Pro1 Digital pl Cir, haven't noticed any vignetting. I think it' s safest to be on the slim side,

Jari

Thanks Jari - I'll hunt one down!

Cheers

[WerTicus]

kenko being hoya but with half the price tag :P