Review on 📷 Pentax SMC DA 60-250mm f/4 ED IF SDM Telephoto Zoom Lens with Case for Pentax DSLR Cameras by Robert Farrar

I purchased this lens from Revain.com in August 2011. I have used this lens from time to time over the last 3 years. Although I'm not a professional photographer, I have a good understanding of what to look for in a lens. Construction: It appears to be a well built lens. It is weatherproof and allows for greater care when used outdoors. Focal Length: 60-250mm - 90-375mm equivalent focal length with PENTAX APS-C sensors. Aperture: constant F4. For a lens of this focal length, this is the best option for the price. You can find a zoom lens with a focal length of 250mm or more at f2.8, but they cost $2,500 and up. Autofocus: Focusing is quick and quiet. I had to calibrate my K-5 with this lens. When I first received it, the images felt soft. After calibration, the results improved drastically (set Fine Tuning to -2). This lens uses Pentax "Supersonic Dynamics" (SDM) to achieve near-silent autofocus. There have been stories of SDM failures. After 3 years, the specimen I received is still focusing with no problems. Image Stabilization: This lens does not have an image stabilization function. This wasn't a problem for me as the Pentax Kx series cameras have image stabilization built into the camera body. Distortion: There is little distortion over the entire focal length. Especially under 100mm. At around 200mm everything evens out very well. Resolution: I must say that at any aperture value from F4 - F13 the images are clean. However, about F5.6 seems to be optimal for center and corner sharpness. Vignetting: Most likely, vignetting won't even be noticed. This "glass" is noticeable at the open aperture. Handling: This is a heavy lens, 1.04 kg. Includes tripod mount. Manual focus is available and smooth. There are no manual aperture settings. Chromatic Aberration (CA): As I said, I'm not a professional photographer and chromatic aberration is the least of my concerns. That's probably because I haven't had any issues with CA with any of my lenses. All I can say is that this hasn't been a problem for me personally with this lens. I'm assuming it's there at some level. Conclusion: A great lens. Professional build quality, weather resistant, very sharp and stable throughout the zoom range. The main disadvantage is the weight. There are better lenses at a much higher price. If you own a Pentax body, this lens should be in your bag.