Sigma 10-20.. New vs Old....

Hi to everyone...

Now I'm searching for an UWA lens for my Rebel T1i... The Canon is twice more expensive then the Sigma in my country, so I don't consider it, because it's just slightly better...I know the Tokina 11-16 is almost the best, but I don't have an walkaround lens(only sigma 50), so I really need these 20mm...

But the price difference between the new sigma and old one is about 100$ (for me it would be about 200$ because I haven't got a 82mm polarizer...)..

So.. the question is: what is improved in the new lens? I've read a lot of reviews: some say the sharpness is increased (but i look at the charts from photozone, difference is about 10-20 units, not so much), some say the vignette and CAs are worse?For me the 10-15 is interesting only outdoors, so the performance at 10mm,f 3.5 not really important... Indoors I need very much 20mm, so how do they compare at 20mm f/5.6?

Thanks a lot for attention!!!

Hello! I've personally had very good luck with the 12-24mm Tokina lenses. They aren't too wide (I dislike a horribly ultra-wide), great colors and contrast, 24mm reach, constant f/4, 77mm filters, and are of a good price.

Speaking of those two Sigmas, I haven't used them, but my research (when I was deciding on an UWA) led me to read that the price difference wasn't horribly justified and the use of the larger filters wasn't convenient. Some reports say the new is heavier, but both versions are suffering from decentering and 'iffy copies.' Maybe someone who has used both can contribute to my answer.

When you say old and new you mean f/4-5.6 and f/3.5? I would personally say the f/3.5 is not worth the extra money. Save yourself some dough and get the 4-5.6