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gooseta · 11-05-2012, 09:09 AM

Can anyone tell me about the sigma 17-70 usm 2.8-4 vs the pentax 17-70? In my time with the 17-70, I found its macro very decent but the sigma focuses 6cm closer, and is faster at the short end, also has hsm like the pentax has sdm. If I get the Sigma I will be able to squeeze in a 35mm f2.4 which I have seen in reviews to be super sharp, I mean it is around 2500 center at f2.4 in the mtf and 2100 corners wide open, and at f4 it's pushing 2700 center and 2400 corner!

top-quark · 11-05-2012, 09:45 AM

Hello again.

Sigma 17-70 is faster than the Pentax on paper. However, F2.8 at 17mm did not produce good results in my experience: bad chromatic aberration and vignetting from the hood. The Sigma is also somewhat larger and heavier which may or may not matter to you. The macro improvement is only marginal and gets less with each iteration (the current model doesn't get as close as the old 2.8 - 4.5 and the soon to be released model won't get as close as the current one). It's still a good lens and excellent value.

FWIW, I've just ponied up for the Pentax. The 67mm filter thread means that I can use RF-75 filters and share them with my other lenses.

Mr_Canuck · 11-05-2012, 09:56 AM

What do you shoot pictures of?

gooseta · 11-05-2012, 10:03 AM

so is the extra 50 quid for the pentax worth it? I don't usually shoot wide open wide angle, but is the iq about the same?

gooseta · 11-05-2012, 10:05 AM

to Canuck
I shoot a lot, portraits, airshows, bifs, macros, nature in general, just getting into landscapes. I have money set off to the side for next year when I will either buy a tele or some primes, depending on budget and what i think i'll need after shooting the 5iis for a while./

gooseta · 11-05-2012, 10:08 AM

Right now I have the K5iis body for £950, 35/2.4 for £130 and battery grip, sd, spare batteries,for £110, So I have a max of £325 to spend, I can afford either the sigma 17-70, pentax 17-70.

gooseta · 11-06-2012, 10:10 AM

so i will be purchasing around friday k5iis w/ 17-70 and 35 2.4, anything wrong with it

gooseta · 11-06-2012, 10:44 AM

also i have decided i will purchase the sigma 12-24 over the pentax 15, i love primes but I may need the added range and it has little ca.

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11-05-2012, 09:09 AM	#16
gooseta Senior Member Join Date: Nov 2012 Location: London Posts: 157 Original Poster	Can anyone tell me about the sigma 17-70 usm 2.8-4 vs the pentax 17-70? In my time with the 17-70, I found its macro very decent but the sigma focuses 6cm closer, and is faster at the short end, also has hsm like the pentax has sdm. If I get the Sigma I will be able to squeeze in a 35mm f2.4 which I have seen in reviews to be super sharp, I mean it is around 2500 center at f2.4 in the mtf and 2100 corners wide open, and at f4 it's pushing 2700 center and 2400 corner!

11-05-2012, 09:45 AM	#17
top-quark Veteran Member Join Date: Oct 2011 Location: Aylesbury, Bucks Photos: Albums Posts: 492	Hello again. Sigma 17-70 is faster than the Pentax on paper. However, F2.8 at 17mm did not produce good results in my experience: bad chromatic aberration and vignetting from the hood. The Sigma is also somewhat larger and heavier which may or may not matter to you. The macro improvement is only marginal and gets less with each iteration (the current model doesn't get as close as the old 2.8 - 4.5 and the soon to be released model won't get as close as the current one). It's still a good lens and excellent value. FWIW, I've just ponied up for the Pentax. The 67mm filter thread means that I can use RF-75 filters and share them with my other lenses.

11-05-2012, 09:56 AM	#18
Mr_Canuck Guest	What do you shoot pictures of?

11-05-2012, 10:03 AM	#19
gooseta Senior Member Join Date: Nov 2012 Location: London Posts: 157 Original Poster	so is the extra 50 quid for the pentax worth it? I don't usually shoot wide open wide angle, but is the iq about the same?

11-05-2012, 10:05 AM	#20
gooseta Senior Member Join Date: Nov 2012 Location: London Posts: 157 Original Poster	to Canuck I shoot a lot, portraits, airshows, bifs, macros, nature in general, just getting into landscapes. I have money set off to the side for next year when I will either buy a tele or some primes, depending on budget and what i think i'll need after shooting the 5iis for a while./

11-05-2012, 10:08 AM	#21
gooseta Senior Member Join Date: Nov 2012 Location: London Posts: 157 Original Poster	Right now I have the K5iis body for £950, 35/2.4 for £130 and battery grip, sd, spare batteries,for £110, So I have a max of £325 to spend, I can afford either the sigma 17-70, pentax 17-70.

11-06-2012, 10:10 AM	#22
gooseta Senior Member Join Date: Nov 2012 Location: London Posts: 157 Original Poster	so i will be purchasing around friday k5iis w/ 17-70 and 35 2.4, anything wrong with it

11-06-2012, 10:44 AM	#23
gooseta Senior Member Join Date: Nov 2012 Location: London Posts: 157 Original Poster	also i have decided i will purchase the sigma 12-24 over the pentax 15, i love primes but I may need the added range and it has little ca.

What lens for K5iis

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