SIGMA 24-70MM HSM

[vincenzo]

Zeiss 24/70 is undoubtably great by all accounts but its:
a/ v expensive
b/ heavy/large for my usage as my main travel lens on A900

I'm therefore seriously considering the Sigma 24/70 HSM for:
a/ compact but solid barrel
b/ autofocus speed and silence
c/ sharpness/contrast almost equal to zeiss?

Or should I consider another alternative? User experience feedback would be greatly appreciated.

P.S. I did search but didn't find a post on this lens/will delete if I missed an open thread already on this topic

[David Kilpatrick]

We tested two samples of the 24-70mm, on Nikon D3, before my son decided it was just not good enough for full frame (nearly all the rave reviews have been on APS-C) and bought the old Sigma 28-70mm non-HSM EX DG lens instead. It cost him 1/4 of the price of the 24-70mm and in our tests, it was much sharper across the frame than both 24-70mms.

I now have a 24-70mm here in Canon fit and I am checking this out on the Canon 5D MkII. It's very sharp corner to corner at f/11. At f/8, wider angle shots shows some loss in the corners and 70mm shots show a noticeable field curvature on distant views, making the corners sharper than the centre in many shots. At f/4, there is very clearly visible blur in all four corners of full frame and the bokeh is very poor - with a lot of coloured fringes that are hard to remove. I would not use it at f/2.8 unless the image was either one where only the centre mattered, or was cropped to APS-C.

Where it is sharpest, around f/8 centrally and focal lengths around 40mm, it is stunningly good but I would not swap my Konica Minolta 28-75mm for this lens.

David

[vincenzo]

Thankyou David for your feedback! I'm wavering! I can buy the HSM version for £500 (from HK) and the 28/70 Sigma for less than 1/2 which is quite tempting, especially as I want to buy the Sony G 70-300mm (partly why I don't want another heavy lens)
I did read a good review of the HSM 24/70 on Lenstip.com and some other good user reviews on Dyxum. I am now considering the Sigma though, especially as its very compact. What is the autofocus like on the 28/70? As it will be my main lens I need a good low-light performance in the auto-focussing dept. Moderate noise is acceptable, clearly the quieter the better, I do have some jobs where speed and stealth are of upmost import. The minolta 28/75 28/70 also get good reviews. I'm wondering which is the best considering my criteria of: small, sharp, fast quiet...

[motor]

Vince look at my forum listing ( which 2.8 to get?) I have both the sigma 24-70 HSM and the KM 28-70. Read my response second to last about my findings comparing the two. I even have 2 pictures posted from the KM. You will be very interested in it. I agree with David, Go for the KM you will not be happy wit the sigma F5.6 -F2.8. Make sure you read my findings first.

Motor

[vincenzo]

Thanks Motor, very interesting read. I'd like to clarify that to me edge performance isn't an issue which bothers me at 2.8-4. I like lenses at these apertures which focus well in low light and do so as quietly as possible. I do require very good centre performance at 2.8 (doesn't need to be stellar) but I actually like frayed edges and vignetting at wide apertures, its part of my style and preference for my reportage photography.
If I want edge to edge sharpness, I'll usually be looking for a lot of depth of field or using a tripod with f11 or so. Therefore I'm still not convinced which way to go. Zeiss is out on weight/size/price Sigma HSM still in, with Minolta or Sigma now under consideration.
Still wondering what's best for fast focussing in low-light?
Vincenzo x

[motor]

The Sigma is definitely faster on focusing it has the HSM. It is almost as fast as my 70-200G which is super fast. Hands down it is faster than the KM, but I'm going to say it again that there is a haze/ softness over the entire picture @ 2.8. You get a faster focus but you really loose sharpness fast even in the center. Why do you want fast focus if you are using a tripod for long exposers? It can't just be my copy either, I have read it several times on the net and even David has experienced it. I teach and use photoshop and you really have to do alot with light adjustment, contrast, sharpness and Viveza to make it go away @ 2.8. Also the Sigma is one fat heavy lens. I like the feel it is balanced on the A700 but the KM is much thiner and lighter if weight is a disadvantage of the CZ lens. I am not bad mouthing the sigma it is very sharp and pulls the colors nicely but you have to have it set at F6-11, outside light with a -.75 or so light adjustment. It is not a good lens at 2.8-4 in my eyes.

Good luck

Motor

[vincenzo]

Hey! I think you misunderstood or maybe I didn't make myself clear. I wouldn't be shooting wide-open on a tripod. 2.8-4 for me would be for reportage in low-light, I also make a lot of indoor environmental portraits, so actually the HSM being wider has a significant advantage for this purpose.
However, I'm quite worried that it has a glaze across the whole frame, including centre at 2.8 - that would be unacceptable. Last night I downloaded some samples and peeped at 2.8 HSM shots and didn't see any central glazing. Perhaps these contradictory results are due to sample variation and other factors such as shooting distance.
At 2.8 I'd largely be shooting subjects at short to medium distances. Also, perhaps with my style and requirements, sharp enough for me might be fuzzy to you or someone else; and that's fair enough. I really appreciate the feedback in any case. I think at this stage I'm feeling like I'll like take a gamble on the HSM Sigma, but first I'll go to my local dealer and see whether its a good balance on my A900. If its too big, as you say that might kill it off for me!

[jbtaylor]

I own this lens. Focus is fast and silent. The Minolta that my wife owns does not compare. Do not have enough shots to really evaluate it but none of the shots taken have put me off. It does tend to expose to the bright side.
Originally I had thought that we would sell the Minolta but I feel that we will keep it for the upgrade to full frame. It seems extravagant but it's too late. I need the faster focus of the Sigma as it will probably be the walk around lens for the a700.

[vincenzo]

Decided against the HSM 24/70 for now. Instead, and for only £300 I picked up the following:
Tokina 19-35mm 3.5/4.5
Minolta 28-135 4-4.5
Minolta 50/1.7
Minolta 100-200 f4.5

Lacking some speed and the 28-135 is not compact, light or fast (so ironically going against everything I was looking for) but I like using A900 at higher ISO's with the DXO tight grain effect and it feels "right" on A900.
Will give this kit a try for a 2 month trip starting in january. Hope I don't regret this new lens kit choice!