looking for a replacement for my sigma 18-50 F2.8

[matikrimerman]

hey all

lately I've started to get really tired of the slow focusing in low light and with high speed objects of my sigma. i know it is f2.8 but maybe it isn't good enough.

so I'm looking for a lens or a combo of 2 that will allow me to focus a lot better in low light situations (and yes , i do use the flash to help focusing).

what are the best lenses out there in terms of focusing?

what is the best value for money lenses in terms of focusing ?

will the 17-40L F4 or the sigma 24-70mm f/2.8 EX DG do better? how good the 24-205 4L IS or the 24-70 2.8 will be?
thanks

[blackshadow]

24-70 2.8L is good in low light.

[condyk]

keep the Sigma as most so called upgrades will add not much value IQ wise and you won't get a faster zoom anyway, but get a fast prime for low light choosing the length according to need. If you're think of the (dubious value) 24-70mm L then you can certainly afford a couple of good primes instead. Better IQ and much better low light performance.

[blackshadow]

I guess it depends how low light you are working. I mainly do concert photography so I do a lot of low light stuff. The main lens I use is my 24-70L but condyk is right if you are in really low light fast primes rule. I have the Canon 50mm f1.4 and a Sigma 30mm f1.4.

[steved110]

there isn't another zoom lens that will improve on the Sigma you have, so look to fast primes as has been suggested. the 35L is highly rated, tho a bit rich for my blood, I'm starting to develop a hankering for the 28mm f/1.8. the sigma 30mm 1.4 is digital camera only so not on my list.