Excerpt: For the price of this lens I did expect a bit better build quality it feels light and cheap and a bit wobbly and it just is not a one off as I have had 2 of these.When I mount a ring flash on this lens the focus barrel sometImes does not want to move which is probably down to the clutch on the quick shift and this is in manual focus mode which is what I used it in 90%of the time.
Excerpt: That said, it's not 100% perfect: the lightness comes at expense of build quality -- it certainly feels less solid than other lenses in Pentax's lineup, and you'll want that hood in order to protect the front element when you're doing macro work. The AF is noisy, which seems to be a problem with many of Pentax's macro lenses, and has a habit of hunting when you're close to the subject. (It's quite quick at longer distances, however.
Cons: Build quality, noisy AF, soft wide-open, purple fringing
Excerpt: This lens is SMALL and it gives great results! However the output is at times a bit flat (probably should try with a hood) and on my copy, the focus ring is a bit "too much dampened" making it a physical effort to turn it. Maybe it wasn't used enough on this mint copy? I will remedy to that.
Excerpt: Updated review: I tested this alongside the Tamron SP 90/2.5, which is simply a brilliant lens for macro usage, with a stop of advantage over the Pentax macro offering in the M range. However, I dont have space in my bag for all these lenses at once and am whittling my collection back. Hence I did a bunch of testing at the weekend. The Tamron is very slightly sharper at f5.6, scoring 60lp/mm vs the Pentax M getting 54lp/mm.
Pros: Compact tele, combination of weight, length and speed
Excerpt: This lens is lightweight, compact and discreet medium telephoto. 100mm lens effectively replaced my 135 and 85mm lens. Resolution wise i compared it to highly regarded SMC 135mm/2.5 and I cannot see any real difference. In my own opinion A 100mm produces better colours, maybe shifted a bit to warmer tones. It is easier to focus than 135/2.5 and but produces bokeh which is not that nice as K135/2.5 or K105/2.8.
Pros: compactness, resolution, colour rendering, A setting