Greetings once again, fellow Pentaxians! I am planning a trip to San Francisco, and wanted the following lenses: Pentax 17-70 and Sigma 8-16. Does anyone have experience with the aforementioned lenses on a K-5? I'm particularly interested in whether the 17-70 would be sharper than my already sharp 16-45, in general. (I am considering selling my Pentax 16-45 and Pentax DA* 55 to finance the purchase, although I certainly don't want to part with either!)
Thanks for any advice!

Thank you, John and Barrie! I shall indeed keep the lens set to "A" mode. I think it's a superb optic, and will continue testing it as time permits, but so far, am extremely impressed with its sharpness and detail rendition on the K-5. As you can see from my main site, www.totalqualityphoto.com, I am very much into the rendition of detail in my images. Have a fantastic year! ~Steve

Greetings!In my ongoing pursuit of image sharpness, I just got the beautiful Pentax FA 43mm f/1.9 Limited lens. I thought I'd try using the lens' Aperture ring, so switched the lens out of "A" mode, and tried setting the aperture manually to, say, f/8. After doing this and looking at the Live View to move the Focus Selection Square over a certain area of the scene, I noticed it did not let me move it around in the subject area. This behavior disappeared after turning off the camera and switching back to "A" mode on the lens, powering up the K-5 and then setting the Aperture via the rear dial on the camera. Is this "normal" behavior for this lens on a K-5? Should one be able to use this FA lens in "Manual" mode with the Aperture ring? (This is my very first "FA" lens, and I did not change the default Custom Setting #27 (Using Aperture ring) Thanks, Steve

Interesting and good to know. Thanks, Dan! I guess I was lucky that I had no apparent damage using the DA* 16-55 with my K-5 in freezing rain! Perhaps I did minimal zooming and manipulation of external controls, but the equipment (and I) sure was cold and wet from about 4 hours of "exposure" to the elements.

Well, I agree that using equipment in the rain isn't my preference, but when shooting the Portland Marathon last October, I had no choice. Fortunately, the K-5 with DA* 16-50 was up to the task, working fine in wet (and cold) conditions! One of the reasons I went with Pentax in the first place!

Greetings, All.
Thank you once again for your expert advice! As it turned out, I brought the DA* 16-50 and the DA 50-200, with the 16-50 getting about 90% of the use! It performed flawlessly. If interested, you can see some sample images at www.totalqualityphoto.com. I recently got the FA 43 f/1.9, largely because of stellar reviews touting its sharpness. I will compare it to the DA* 55 and my current "sharpness king", the DA 70 f/2.4 Limited.
May you all enjoy a happy, healthy and prosperous 2012!

Hi Archie. Thanks for your useful information! Actually, I had seen reviews of this lens only after getting the DA* 16-50. I agree with your points, but I jumped at the 16-50 because I liked the "pro" build, SDM, and the extra mm of wide angle focal length. True, it's bigger and heavier than the DA 18-135. That's why I'm still wrestling with bringing my DA* 55 as well, though I really want to travel as light as possible.
In any case, I appreciate your expertise! Regards, Steve

Greetings!
I have a Pentax K-5 with a few "WR" lenses (DA*16-50, DA*55, DA 50-200 WR). I plan to shoot landscape, city, and marathon shots in Portland, a city known to have "wet spells". I was planning to bring the DA* 16-50 and the DA 50-200 only, keeping it simple, but now think that the DA* 55mm f/1.4 would be a great "walk-around" lens for when I wanted a smaller, lighter kit. (The 16-50, while an awesome zoom, may be rather large and heavy for "discrete, fast" work.) Question- Would the DA* 55 make a good addition to the travel kit, or would it simply cause more "angst" in determining which lens to employ? I figured with the 2 lens kit, my decision-making would be much easier! Thank you for any advice you may provide.

Hello Fellow Pentaxians!
Thanks for the welcome to your group. You are all correct...I do love the Pentax K-5 and assorted DA lenses, especially the 70 f/2.4 Limited, the 35 f/2.8 Limited, the DA 50-200 f/4 WR, and the DA 16-45 f4! Not having done formal lens testing, I would subjectively guess that the 70 f/2.4 is the sharpest of the bunch, but the 35 Macro Limited and the others are not far behind. In other words, I am glad I made the decision to go with Pentax! I hope the Pentax/Ricoh marriage proves positive technologically, and that Pentax maintains its optical and build quality of both cameras and lenses. Thanks again for the welcome!
Regards,
Steve
www.totalqualityphoto.com

Greetings!
I am a new Pentaxian, about to acquire a K-5, DA 15mm f/4 ED AL Limited, an 18-55mm f/3.5-5.6 AL WR, and a 50-200mm f/4-5.6 ED WR. (I aspire to the DA 35mm f/2.8 Macro Limited and perhaps the DA* 50-135 f/2.8.)
I had been recently using a Lumix m4/3 G2, other assorted digicams (Sony F828 for example) and Nikon film cameras long before digital was a reality. I'm into "sharpness", and despite having using large format optics in the past, I am blown away by the image quality of Pentax lenses and the build/ergonomic quality of Pentax DSLRs! If interested, please see my website, www.totalqualityphoto.com, for more details. Thank you!