sigma 70-200 mkII

I haveowned this lens for about 6 months now. It's a sharp lens, even at f/2.8. I see in comparisons w/ the Canon 70-200 f/2.8 the Sigma looks sharper at f/2.8 thoughout the zoom range. See comparison - http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=242&Camera=9&Sample=0& FLI=1&API=0&LensComp=469&CameraComp=45 3&SampleComp=0&FLIComp=1&APIComp=0


I used it for a wedding w/ good results but I find now using it for some more detailed photos it's having a few issues. I had a lighting setup configured for some product type shots consisting of a softbox nearly overhead, each side of table the product was placed on were white matte reflectors and a softbox on other side of soft box but lower to reduce any shadows. I shot some cooking ingredients - garlic, basil leaves, shlots - and they looked quite nice. However, I also had a black bowl filled with a couple more garlic cloves. In the shots on the rim of the bowl, ever so slight is yellow fringe on part of the circle. I know this will cause rejection for sure at istock. I shot w/ sigma at f/11 to f/13 at 1/125, iso 100. I also shot a glass bottle w/ olive oil, set on a mirror to give a real nice look of full bottle plus reflection, isolated w/ white. Here is where I really got annoyed. The metal dispenser at top of bottle (it's refillable, not the bottle the olive oil comes in) has too much purple/blue and there is RED all around the metal. Ironically I had just started using ACR for converting raw images and I noticed on the lens fix section you can fix red/cyan in chromatic aberration. I haven't really noticed red before. The metal top had both red and blue anda black dish isolation done seperately had a red ring around top of bowl. Each were shot at around 100mm.I shot the isolations at f/16 & f/22 to get the whole thing in focus. One advantage of the sigma was the "macro" capabilities. I am very disappointed in the results. In the end I reshot w/ ef 85 f/1.8 at f/16 for bottle and NO blue or red. I am a big fan of primes but it's nice to have one zoom in the bag. I have photographed my sigma lens and it may have togo up for sale. I'd love to see if the chromatic aberrations would be found in a canon zoom either the f/2.8 or f/4 version using the same lighting and materials. I'm guessing probably not. Either way I've had a few rejected w/ sigma 70-200 for chromatic aberrations that I didn't really see (though accepted by other stock sites). Basically I need a lens w/ little chroma as stock is insanely anal about it as I'm sure most of you know.


How is your experience w/ your canon zoom concerning chroma? Would my lighting setup cause chromatic aberrations in most zooms? Any help is appreciated. I have my sigma already in its bag getting ready for sale. So sad, it was almost a perfect compromise zoom to canon.

my experience with istock is... they know nothing about what a good photo is, and are looking strictly at technical issues, if you shot a technically great photo with excellent sharpness, no noise, no dust etc, even if the subject or photo itself is horrid, it'll still get accepted... nothing against them, just compare their images with corbis or getty. but with that being said.. I'm guilty as u r since I still use istock. and I use only L lens or macro for image submitted. anything else gets rejected and I'm just not willing to spend that much time cleaning up the image and fixing the CA just for a few bucks.


so instead of trying to find out what's causing chromatic aberration (on the lighting side) just use a macro or L grade lens and you'll be fine, usually it's the lens itself anyway. zoom lens tends to be more prone to CA unless they cause u an arm and a leg(L).

Good point about istock. I do get frustrated at some of the rejects I get there and then I see some of the accepted images that have little composition and are hardly stock. Anyway, I am in limbo as far as selling lens. I check the ca comparison with the canon l 70-200 and it's six on one hand and half a dozen on the other. The sigma seems sharper at many levels except at 200mm. Besides in looking closely at CA I see it in pretty much every lens, though some better than others. THe 85 f/1.8 did the trick of no ca and it's not even L. I still am considering selling the mkII and getting a 135L but if I get another wedding job I'd still want a zoom and for the price really the sigma can't be beat. Then again, I could just add the canon 100 macro without doing the other thing. We'll see. Thanks foryour input ultima.