Sigma 17-50mm f/2.8 EX DC OS HSM Lens for Pentax

Comments:

I was primarily looking for a faster alternative to the 18-55 kit lens and my 16-45mm F4 which I love dearly and use most of the time. But i needed something fasterand with better in low light and Wedding situations. Sigma's 18-50mm is definitely a very decent lens and the photos are very good but i wish they were just a bit sharper. AutoFocus seems quick except when at the 50mm end where i experienced a lot of hunting in semi-poor light conditions. Putting the lens into manual mode definitely works better during these times. Bokeh seems fine and i have not noticed too much flaring as others have reported. All in All, its agood lens and highly recommended. Juts wish i would have waited two weeks or so as the lens has dropped in price $50 since i bought it three weeks ago.

Comments:

I needed something quicker and with better low light functionality than my 16-45 F4 (which I love for outdoor landscapes and nature photography)and this lens does just take. Vignetting is not an issue so far and I have not yet experienced an issues with flare performance but other reviewers have noted issues. My only noticeable issue is that opening up at 50mm even in semi-well lit situations, the auto-focus tends to be jittery and choked up on two occasions. Lens is also very heavy but the construction/durability seems top-notch. Sigma has removed their patented OS system on the Pentax mounts for obvious reasons so don't expect to see the On/off switch on the lens barrel. I would definitely recommend this lens for the performance and price point.