Summary: This lens is extremely fun to use for photo or video. The images are extremely crisp and video is very fun and easy with such a short focus ring allowing you to do quick focusing pulling with shallow depth of field. This lens also creates very round bokeh from great aperture blades. The nature of a 40mm/60mm is that it creates a framed shot for you. A natural view of your surroundings comparable to the human eye.
Summary: I haven't tested it extensively yet, but with the few test photos I shot, I noticed a marked difference in the sharpness/photo quality of the pictures taken with this lens vs my kit 18-55 and 50-200mm lenses. I winced to spend the money but after reading reviews I thought it might be worth it. It's worth it.
Summary: I have had this for a while. I must have taken a thousand shots by now. I can admit that this is a superb lens considering its size and price. great center sharpness wide open. gets better as you stop down a little. Makes a lot of noise when focusing in low light. Not much to complain about but, worth noting. You will hear it in your video for sure. love the lens so far.
Summary: I have a lot of good to say about this lens, so let me start by telling you whats bad to just get it out of the way. 1- Purple fringing can be strong but only in significantly high contrast situations (tree branches in the gray sky, white fence/ or white floweres with sun hitting it, etc). Also occurs worst wide open at f2.8 stops to 4 stops then is gone.
Summary: Very small and light, goes very well on my Pentax k-5. Focus speed is fantastic, and makes a very small and portable camera setup. The only problem are the rubber lens cap and it does not come with lens shade.
Summary: I bought this lens as my first prime with birthday gift cards, and I love it. I do a photo-a-day challenge and this lens is great for hikes, walks, and street photography. It is so small that my K-r looks like a large point and shoot and definitely helps me not feel so awkward when I'm out taking photos in the street. Its tiny size is great for street photography since it has a 0 intimidation factor.
Summary: I wanted a lens for street photography that would not immediately identify me as a photographer from a block away. Even my 50mm f/1.4 prime was larger than I wanted. I had been debating purchase of the Limited version Pentax initially introduced but didn't want to pay the price. This lens was 2/3 the price, made for a different market, but it works well on both my K-5 and K100D Super bodies.