Sigma 18-250mm f/3.5-6.3 DC OS HSM
Conclusion
With the 18-250mm DC OS HSM, Sigma has set a new standard for superzooms. Tamron made a step forward with their 18-250mm, adopted by Sony. The Sigma goes a stage further, reducing distortion levels, improving full aperure sharpness at the long end, controlling CA and vignetting while offering a useful dual choice of image stabilisation methods on the Alpha system bodies. Unlike the Sony, it does not auto-crop when fitting to the Alpha 900 body and can be used at 250mm (only) with full frame coverage, smoothly but strongly vignetting. At all shorter lengths, a circle appears to define the frame; at 18mm, you can crop a 4264 x 2843 image and just avoid corner cut-off, which equates to a 1.42X factor or a 17mm view, really not worth trying! But you can also get a decent square wide-angle shape from the same circle.
Examining the image using the Alpha 900 shows how well the distortion and vignetting have been controlled. Between 35mm and 50mm, the lens is almost as good as you would expect from a prime in that range. There’s a patch of stronger distortion around the 80mm zone, but it reduces as you pass 135mm to leave a class-leading long end.
The price of the Sigma may be a little more than the Sony in the UK, at current street discounts. I would say it’s worth it, but try the lens if you can. The zoom action is nothing at all like the really sweet, light weighting of the Sony. It has resistance and this resistance is not constant, there’s a definite midrange ‘lump’. There is no direct manual focus but the HSM is a positive benefit despite that. It’s heavier, larger, takes non-standard large filters and you must remember when using OS to turn off SSS or your shots will be spoiled. Equally, if you use this lens, you must remember to turn SSS on when switching to other lenses.
Shirley works almost exclusively with one lens, and the Sigma has replaced the Sony in her kit – because of its superior performance at all apertures which makes it Program-mode friendly, no need to set Aperture priority f/8 as a startpoint which we do with the Sony.
I now find we have more Sigma lenses in the working outfits than Sony lenses. This was not intentional. In fact, there are very few real Minolta or new Sony lenses in our kit – the 28-75mm and 17-35mm are really KM rebadged Tamrons, the Sony 18-250mm was always really a Tamron. Just the 16-80mm, 16-105mm, and 70-300mm SSM remain to represent the current OEM offerings in our system.
Postscript: after more than a year of use, this lens continued to be firm and solid in action.
– David Kilpatrick
OK – time has come to decide between new lenses for the A77 that is on order –
Sigma 18-250 OS HSM or Tamron 18-270 Pz motor?
I managed to take some more shots today, did some experimenting with
aperture and ISO settings. Double checked that OS was off and SSS on.
I took a number of pictures in the f8 – 11 range. 18mm, 250mm and a few macro shots. For the macro shots, I tried both manual and Scene/Macro settings, didn’t make any difference that I noticed. I tried the f11-16 range.
I hate to say it, but I am not impressed.
The image quality at low ISO (800 and below) is about the same as my P&S up to about ISO 200; but going to higher f numbers forced me as high as 1600 ISO …in bright daylight. So stopping down the aperture starts to cut into the advantage of the better ISO noise.
Macro IQ is definitely better on the P&S.
I do see some stunning images on the web from this setup, but right now I’m thinking there may be a lot of PP involved. I certainly never came close to “stunning”.
This being a lens review article, I feel a bit guilty bringing the camera body into it, but I can’t really separate out whether it is a limitation of the lens or the body. I concede it may be me, but I sure don’t see what I’m doing wrong.
I really was hoping for better low light performance (got it), more features (got those), and better IQ both in good light(nope) and macro (nope).
I’m pretty disappointed. I did a lot of research and this combination came out as about the best all-round setup I could find. I really wanted it to knock my socks off … but I think it goes back in the box and back to the dealer.
I don’t know whether to bother trying one of the other manufacturers, or whether to give up on the superzoom idea and go to lens swapping.
Or maybe just forget DSLR’s altogether.
Anyway, thanks for your help David. I’m glad the lens/camera works for you, I guess maybe I just had unrealistic expectations.
Thanks for the quick reply and the tips David!
It’s raining here in southern NH/USA so I can’t get out and do test shots right now, but as soon as I can I will and will get back to you.
Your tips about aperture may be the issue; the quick shots I did last night were as wide open as the lens settings would allow; so maybe that’s the problem.
I was using SSS, with the lens OS off. I doubt I can be patient enough for that long wait for the OS to activate !
I hope I can get this IQ straightened out, other than that (which is key of course) I really like the setup.
I guess I’m looking for a sanity check. Never had aDSLR before, just bought a Sony a55 and Sigma 18-250 and am surprised at the relatively poor IQ compared to my Canon Sx120 P&S. I expected IQ to be better in all lighting, but so far (only a few test shots, can’t do many if I want to return it – which I think I do), disappointed.
At high ISO, the a55/Sigma is clearly superior.
At low ISO, outdoor shots in good light, both macro and wide, the Canon P&S IQ is better. Much unexpected!
Is this common, that a P&S IQ be better at low ISO?
Or maybe there is technique I’m missing … maybe just because I’m not at the ‘sweet spot’ aperture for the sigma?
Been shooting at the lowest f-stop possible. Maybe that’s bad?
Reviews for both the a55 and the Sigma are all good … so if this is as good as it gets I guess there’s no point in trying other DSLR / lens combinations 🙁
Clearly something is very wrong as the A55 image quality at low ISO is superb – and the Sigma is the best lens of its type. First of all, the Sigma is generally at its best around f/8 to f/11 on the A55. It will not be capable of good macro shots at 250mm and f/6.3 (wide open is never sensible with any long range zoom) and the depth of field will not be sufficient for many subjects, so for macro work I would always try to use f/11 or even f/16 and move to a higher ISO. It is noise free up to ISO 1600 if processed correctly from raw, and this is very useful for macro. If you try to stop down to say f/16 or f/22 for routine work you’ll just get soft images (diffraction) and probably subject movement at low ISOs.
One thing to be absolutely sure about is the SSS setting and OS on the lens. We use the lens OS, it really helps with viewing at longer lengths. This means the SSS in the camera MUST be set to OFF in the menu. If you leave Steady Shot set to ON, you will get very unsharp images when the Sigma lens is also set to OS, the two systems will overcompensate or even work against each other and blur the image badly.
David
Thanks a lot for the review, very detailed and very interesting indeed. Did you try it on an Alpha 55 which you reviewed as well?
Thanks again for what you do David for the Alpha users.
We’ve used the 18-250mm on the A55 and our sample works well enough except for one small issue, from time to time the lens can lose contact with the camera. It needs a factory fix to be perfect because it is an early example of the lens. Service is restored by simply pressing the lens release button and briefly shoogling the lens, it seems to be a mount-fit issue nothing else.
A very interesting review….. I have the Tamron 18-200 and really loved it when I first bought the lens, but now it is starting to feel a little long in the tooth, or my photographic skills have improved! The implementation of HSM is an obvious drawcard for this lens, and thanks to your review, I might have to start saving up for it……..
Your reviews always show the users’ perspective, not just the technical jargon that you get elsewhere. The important part of how a lens performs is how if feels on the camera, and the resulting images that it takes along with how much extra work you need to put in afterwards to get the image right! To me, the less that has to be done, the better!
Thanks again!