Sigma 17-50mm f/2.8 OS HSM user report

[roysmith]

I recently got this lens, and I'm using it on my A700 and A100. Overall it's much better than my old SAL18250, better contrast, sharper, much faster and quieter AF and brighter. I also have a Sigma 70-200 2.8 HSM II and two bodies so I don't really miss the SAL18250 range
The optical improvement is easily noticed by just looking through the viewfinder, and the accuracy and speed of the AF is light years from the 18-250mm. Maybe not quite as fast as a 50mm prime but very close, and whisper quiet.
The OS seems to work a bit better than my A700's SSS, and the stabilization is noticeable when composing the picture. It doesn't make much noise, it's barely noticeable if you put your ear right next to the lens. It does however make a "click" noise when turned off or entering standby.
Image quality is good at f/2.8, and outstanding at f/4.0 and up. It's specially good at the widest focal length, degrading a bit at 50mm f/2.8 but still quite good and totally useable at that "worst" setting.
Chromatic aberrations are well controled but still noticeable... but anyway, not even near as bad as the SAL18250. They are better controlled than my Sigma 70-200mm, even at 17mm f/2.8.
Distorsion is OK and looks better than the SAL18250, less "weird" that is It's mostly noticeable at 17mm, at longer focal lengths it almost disappears.
Construction quality is very good, feels very solid. The hood however, although of good quality, doesn't fit very well and feels quite loose. I had to put some tape on the barrel to make it fit tighter.
I'm attaching some test pics with full EXIF and minimal processing (just some sharpness and a bit of NR adjustments with LR3).

[roysmith]

A couple more:

[Dr. Harout]

Not bad, not bad at all. I do notice the CA, but as you say, can be fixed.
For all who want to look at EXIF, after clicking on the pictures, view it at full size and then you access the EXIF.
I guess the newer construction of Sigma lenses is much better than previous ones. Though I will still not trust those with screw drives, but the HSM lenses are tempting me.
Anyone who could compare the new Sony 18-55 SAM with this lens?

[Juanito200]

Thanks for the report. I definitely am going to look at it as a replacement for the kit lens. IQ looks good, and CA I can live with, and quiet to boot! I like the idea of the OS being able to be seen in the viewfinder (I don't have the steadiest of hands). I guess it would be even more useful on a telephoto. HSM is sounding good, as I have been using the a700's DMF recently, but it would be nice not to have to hold the shutter button 1/2 way down to use it.. Thanks again roysmith. John

[roysmith]

Sorry forgot to report about that: This lens doesn't have full time manual focus (i.e. like the Sigma 70-200 HSM). So the only way to focus manually is to disable the AF using the switch on the lens. Don't know why they made it that way... I suppose to keep the price down, but it's a shame really. I was used to work with the AF/MF button on the A700, but unfortunately that can't be used with this lens. And DMF won't work either, sorry

[agorabasta]

Too much CA to use it for JPEG shooting. But even in those JPEGs the CA is easily correctable; and it's quite correctable even at f/2.8, which means there's no LoCA even wide open. And then it's pretty sharp into the corners even at 17mm f/2.8 after corrections. That's very good result.

It's a real shame we still don't have automatic CA correction in Sony cams...

[bfitzgerald]

Just a bit of information on this one but I did a bit of a test with a few lenses I have and discovered some differences in actual field of view.
18-135mm is very close to the 18-70mm FOV, but a fraction less by my shooting
The Tamron 17-35mm on APS-C has slightly less FOV than the 17-50mm f2.8 (obviously on FF its FOV is much bigger)

Of course this is about the Sigma, which I have yet to test. However a good friend of mine bought one (likes it happy overall) but swears "blind" that it's "no way a 17mm lens"..more like an 18mm at the wide end

Suspicious I checked the Sigma site and the angle of view (in degrees) is stated as 72.4
The old 18-70mm is evidently 76, the Tamron 17-50mm spec says 78.45
And just for reference a Canon 17-55mm f2.8 is 78.30 with a Nikkor 17-55mm being 79 degrees.

I can understand a slight difference, but the Sigma seems off here. Unless I missed something

[classiccameras]

From what I have read else where including the Dyxum forum, the new Sony 18-55 SAM 11 has outstanding IQ for the price, but still has a crappy construction. Its one of the best kit lenses from any manufacturer for IQ.

[bfitzgerald]

Be careful what you read!
I've tried the 18-55mm II and it's basically the same optics wise (bar a rear element change) as the first version. Zoom action is a bit smoother, it's got the newer styling and quieter AF, but it's not any sharper than the old version.

I sold my original for 60 euros after the old 18-70mm beat it hands down in my little test. It is however quite a good lens for close up shots on a budget (0.34x I believe)
Def do not bother buying one on it's own, looking at DK's A58 review his copy sucked pretty badly (worse than my original)

Dyxum can be a useful resource, but anyone rating the 18-55mm 5 for sharpness and stating "You wont find a better lens for the price. If you don't need the larger maximum apertures, don't waste money on expensive 17/18-50 f2.8s which won't be any better. This lens is that good."; is smoking something pretty strong

Even a good copy will get destroyed by the 17-50mm's, the 18-135mm takes it apart big time too. Some reviewers get carried away and lack experience with other lenses to give impartial and accurate statements. A good copy is ok/passable at best, nothing more. And anyway these Tamron/Sigma's are not that expensive..it's not like you have to lay down £900 for one

[classiccameras]

Ok, I take Barry's points on board re the 18-55 SAM 11 kit lens.
I have both, the Mk 2 was thrown in at no cost when I purchased a used A57 and the Mk1 was on offer with the A37, neither lens has disapointed me and accepting the very cheap and basic build quality, they perform pretty well optically, I have no complaints re sharpness or colour rendition and would happily go on a general shoot with one or the other just as lightweight kit to carry for the day.
However, I agree with Barry about the 18-135, its a cracker for the price, I love it. When I can afford it, I will probably sell both kit lenses and either get a Tamron 17-50, Sigma HSM 17-50 or Sony 16-50. The Tamron seems the best deal, but I think I will wait and see what transpires on the Alpha mount front before I throw any more money at the system.

[bfitzgerald]

If you get a 17-50mm Tamron I'd suggest a grey market one and save the cash, I got a mack warranty and the total cost was about £200 including delivery, that's a nice bit less than the UK price.

18-135mm is good I might keep it, but the price has gone up a lot in recent weeks. I don't think I'd pay £360 they are asking now for one, it seems better suited to the £250-£290 odd price range in line with Canon's 18-135mm STM price. I'm not sure what Sony are up to lately they seem to be on a price rampage on "some" lenses.

[bakubo]

There is also the new Sigma 24-105mm f4 DG OS HSM that might be interesting for people with FF. Similar to the Canon 24-105mm f4 IS. I don't know the price, but probably not cheap.

[classiccameras]

The Tamron 17-50 really does put some of the Sony lenses to shame, ecpecially the CZ 16-80. My only reason to buy a Tamron 17-50 was for the constant F/2.8 and the slightly longer reach than my 17-35 KM lens. At the moment I want to wait and see whats going on with Sony.
I think if I sold my Sony 18-135, I would miss it, and it would now be too expensive to replace, its just so darn useful and a good performer.
Yes, a grey import is much cheaper, how does the UK warrenty work or doesn't it on a grey market lens.

[Birma]

I agree that the Tamron 17-50/2.8 is very reasonably priced, and I enjoyed using mine on the A100 and A700. However, I have not gone back to it once since getting the CZ 16-80. I have never missed the f/2.8 aperture for my purposes, and I appreciate the extra zoom length of the CZ. My other preferences are subjective, but I do prefer the CZ's images. It is something I think has to be tried. Just providing an alternative view .

[classiccameras]

Birma, your probably right about the CZ 16-80, it does exhibit excellent colour rendition and IQ generally is top notch with a couple of areas in the zoom range a tad below par, but then no zoom is perfect. Its construction and quality of parts for the price could be better. The Tamron is a steal by comparision on a price/performance basis.
I must admit, I would like a CZ but its too expensive for me.