Sigma 24-70mm.

Hi, I'm thinking of getting the sigma 24-70mm hsm for my k7. Being very new to photography, (about 3 months!), I want to know is this suitable for the k7 and has anybody any comments on this lens? Thanking you in advance.

Depends on what you want to use the lens for if it's considered suitable or not and what other lenses you've?
I think the focal length is handy for walk around lens, it's just wide enough I think but of course that's personal.
The focal length is also very handy for portrait.

Thanks Stefan, what I meant by suitable was that I wasn't sure if this lens was for full frame cameras only. The only lens I've got at the moment is pentax 18-250 which is fine, I just want to upgrade a bit on the quality.

This focal length range is a hang-over from film days, when it provided a nice balance between wide-angle and moderate telephoto, and therefore made a good general-purpose lens.

Like the superb Pentax 24-90, it's not so useful on digital. I sold my 24-90 for that reason, though optically it was one of the best zooms I have owned.

The equivalent for a DSLR would be the Pentax 16-45, and there are several going fairly cheaply at the moment.

G

FF lenses fit on crop without a problem.

Dont get your head into equivalent 1.5x matter if you never used film.
24mm would be the same as 24mm on your 18-250mm no matter what lens you used.

I have the same lens, if its this one? http://www.sigmaphoto.com/shop/24-70mm-f28-ex-dg-macro-sigma
Its a nice lens and hiving the constant f2.8 throughout the zoom is nice. Its great quality but it is on the heavy side at 700g.
Here's a shot taken with it.


Taken wide open at f2.8

I have that one - the 24-70 HSM f2.8 and it's roughly 50-50 if I have that on the body I'm carrying or the 10-20mm HSM. It's excellent quality, but as Stephen says, it's heavy. Great walkabout lens.

C

Thats the lens I mean. Whats it like for portraits? Any samples?

no samples but the length is usefull.
You can make full portrait at 24mm and you can make a head shoulder portrait with 70mm without coming to close.

I don't classify my photos by lens (sorry) - so I can't definitively give a sample, but I am very happy with the lens and it's one of the last I would be willing to part with should push come to shove.

I'll be using it this coming weekend (hopefully) - another baby shoot so if I remember I'll post results here.

I can certainly say it is an excellent lens.

C

These guys use a lens with the same range for portrait, just to give you an indication http://lightenupandshoot.blogspot.com/

my two cents ...
1. on paper, 24-70mm is a wonderful range for both full frame and aps-c format. It is 36-105mm ff-equivalent on the aps-c sensor. Some may say it is not wide enough or long enough but i dare say 70-80% of the best pics of many photographers (serious hobbyist or pro) falls within this range.
2. Sigma is the only brand that offers this range in fast constant f2.8 so there is really no alternative if you are hooked on the f2.8 factor. 3. I would think the Pentax FA 24-90 (rare) and the DA 17-70 sdm (more versatile and available)can give you comparable image quality f-stop-to-f-stop against the Sigma. So the question boils down to whether image quality at f2.8 is good enough. I have tested a 2nd-hand Sigma 24-60 EX f2.8 (favourably reviewed by many users) not so long ago and I am not that impressed with its performance wide open - very prone to ghosting and color fringing in high contrast area, and not an eye-opener in terms of sharpness and contrast (acceptable but nothing to rave about). I have the same observation from a Sigma 30mm f1.4 EX test shot. Image starts to look impressive at f4 but showed no advantage over the DA 16-45 in my side-by-side test shot. The 24-70 maybe a whole different story but only your own test shots would tell.
4. Some are turned off by the bulk of the non-hsm 24-70 to be a practical walkaround lens and the hsm version is even bulkier. Its just pure physics that bulk adds drag , and the price is a loss in responsiveness and agility of casual shooting. Again, only you can tell if it fits your shooting style and needs.

I have the early 24-70 EX DG, it is sharp and focus is fast and accurate, there's only minor distortion at 24mm, the filter size is 82mm (expensive). It's heavy but very well built, handles nicely with the K20d + grip, it behaves a bit like the A 35-105/3.5 did on film, but on digital...........a good walk around lens! In all it does nothing very badly, just gets on with the job......oh the rubber grip attracts dust easily. It's just a good allrounder and slots in nicely between a 10-20 and a 70-200. I'm a prime lens man so the best recommendation I can give is.........would you buy it again? Yes I think I probably would

Regards,

John

24 isn't as wide as it was in the film days, but it is as wide as my last compact camera (Panasonic DMC-FZ7, 36mm-equivalent at the wide end). Depending on what your photography interests are, the extra 20mm at the long end might be more useful to you (particularly for portraits) than the extra width.

However, if you are primarily a landscape shooter you might want to consider alternatives: the Tamron 17-50 f2.8 (though it doesn't have HSM or quickshift) or the new Sigma 17-50 f2.8 HSM (though it isn't out yet). The latter is about the same price as the 24-70, and sacrifices some of the long end for extra wideness. The Sigma 17-50 also has their in-lens OS system (even in Pentax fit): I don't know whether there are any reviews comparing the performance of this to the SR built into Pentax bodies.