Tamron 17-50 f2.8, Sigma 18-50 f2.8 or Sigma 17-70 f2.8-4.5?

I have a 350D/Rebel XT and I'd like to replace my 18-55 kit lens with something of a similar focal range. I've narrowed it down to about 3 within my budget. Now I can't decide.

It'll be my walkaround lens and will also be used for landscapes so it'd be good to know which of these is sharpest at the wide end.

I've read quite a few threads about these lenses individually, any comparisons would be greatly appreciated!

Thanks,

Jon.

Tamron 17-50 got good reviews. But Sigma 17-70 got both range and optics

I went for the Tamron

i don't think you can go wrong with any of them.

if you're thinking about having a full coverage when combined with a 70-200mm lens, then the sigma 17-70mm may be the one to ensure full coverage. but if you can make it without that 20mm, then go for the speed with the other two.

I have just taken delivery of the sigma 18-50 and very happy so far. Purchased through jessops web site and added 'pricedash' as voucher code. Cost me £258

Thanks for the suggestions. To add to the confusion, I just read about Sigma's new 18-50 EX Macro.

i wouldn't worry too about it, cause most of the time one will be using the lens for more 'normal' range. btw, the minimum focusing distance are as follows:

sigma 18-50mm - 28cm
sigma 18-50mm macro - 20cm
sigma 17-70mm macro - 20cm
tamron 17-50mm - 27cm

not to mention if you decide to get a filter, youll need to spend more...at least thats how i make myself happy that i bought a 18-50EX.

and so far, loving the lens

I vote Tamron, I've read a few reviews of both, and even though they seem to both perform very well IQ wise, the Sigma has a few disadvantages (flaws, I can't remember, I think it was vignetting or something).

jcw122 wrote in post #2061331
I vote Tamron, I've read a few reviews of both, and even though they seem to both perform very well IQ wise, the Sigma has a few disadvantages (flaws, I can't remember, I think it was vignetting or something).

purple fringing. I just encountered my first horrible case of it but thats b/c I was shooting straight at a light source...stupid noobs

All three lens are review at the site below:

http://www.photozone.d​e/8Reviews/index.html

Tamron has the best optics of the three but is the most expensive.
Sig 18-50 has good optics but a bit of distortion and CA, but it's price is good and it's fast.
Sigma 17-70 has great optics and it's slower, but it's got the best range.

I went with the Tamron

I liked the Tamron 17-50 f/2.8 enough to buy it, even though I already had the Tamron 28-75 f/2.8. Both Tamrons are sharp, sharp, sharp.

I like Sigma, but to many people have complained about the quality of the Sigma 18-50 f/2.8. It's hit and miss if you get a sharp lens or not.

For a walking around lense the Sigma 17-70 would be a nice lense, but not as good in low light. So, it all comes down to what you want to use the lense for the most.

--Evan

I chose the Tamron 17-50 for the excellent optics, and constant 2.8 aperture. One of the things I knew I wanted out of the kit lens was it to be faster in low-light and it would never perform without a flash. So I didn't go with the Sigma due to the variable aperture and the apparent quality control issues. I am happy thus far with my decision.

Another vote here for the Tamron.
Very sharp lens and still quite small and light.