Summary: Bought this lens with some trepidation because of concern over SDM failures. I "needed" a lens in this range and 3rd party lens makers really didn't have what I wanted. There were reports that the SDM was remodeled in 2012 (hope that was true and not industry talk) because of the failures in both the 16-50 and 50-135 models (shared the same SDM design). It was well into 2013 when I bought this lens.
Summary: I bought this lens through a well-known used camera distributor, so I thought the AF problem would have been checked out and fixed. Nope. Towards the end of the zoom range, it could not find its focus. It would front focus, then back focus, over and over until it seemed to just give up. I loved the image quality and everything else about the lens, but I can't have a lens that won't focus.
Pentax 50-135mm f/2.8 ED AL IF SDM SMC DA* review by Waratah
22 June 2013
Summary: Helluva lens. From f3.5 and up has never let me down. Early I tried the 2.8 in unsuitable situation (hasty glamour shoots in nature etc) and was frequently underwhelmed but now I understand it better - its just brilliant. If Pentax ever need an idea for a new lens - combine the best of this lens with the best of the 18-135 and create a 30mm ish to 100-110mm ish constant aperture , WR, DC focus lens I'd be over the moon.
If you are considering buying this lens dont hesitate, highly recommended.
9 June 2013
Summary: Purchased this lens to replace a 70-200 f2.8 which I found to be heavy and difficult to handle. I use a K5 camera with grip, this lens is just perfect, balances beautifully with this camera and the 50-135 focal length is so much more useful than the previous lens. The IQ is simply fantastic and has that certain quality that make images really pop. Autofocus on the K5 is fast, virtually silent and very accurate.
Incredible lens. Makes a great k-30 body into a stellar performer.
4 June 2013
Summary: Bought the lens following the glowing reviews. Never been happier. Lens is on a k-30. Had to adjust focal distance. Mine is at -4, following which the pictures are absolutely breathtaking. The colors are vivid, coloration is natural, not yellowish as on canon L lenses, and sharpness is unbelievable. I can count dimples on a subject's face, and sift through individual hairs. Took a few pics of woodpeckers. Can count the feathers.
Pentax 50-135mm f/2.8 ED AL IF SDM SMC DA* review by dugong5pm
4 June 2013
Summary: I have used this lens with my K-x, K10 & K20. This lens has a DA* (star) title, which supposed to be a performer. AF is fast & accurate, even on the K-x body. It focuses instantly & silently. Image quality is good, though not of the best telezoom I've ever tested. Pentax always have that design advantage compered to other, and this lens is one of them. This is a wonderfull lens by design.
Pros: light, compact, silent, fast AF, fast f/2.8, weather sealed
Pentax 50-135mm f/2.8 ED AL IF SDM SMC DA* review by hikenhi
25 January 2013
Summary: Bought a lightly used copy of this lens in near mint condition. It's an awesom lens for walk-around photography or if you're carrying it over great distances like I often do on my backpacking and mountaineering trips. I own a Tamron 70-200f2.8 and that thing is a tank, almost twice the weight and 3 times the volume of this lens in it's carrying case compared to this one.
Pros: Lightweight, Compact, Professional Build, Internal Zoom, Bokeh, Sharp, Price