Continuing in my quest to find a decent general purpose zoom to use with my Sony a6500 camera, I've just taken delivery of a used Pentax 28-70 mm f4 AL lens. This is a light and compact lens. In common with other early autofocus lenses from Pentax the focusing ring is a bit loose and vague, but it's not diffcult to achieve accurate manual focus. Working at f8, my initial impressions are reasonably favourable. From 50 to 70 mm it appears very sharp across the frame. Below that the edges fall away a bit, with 28mm being the weakest focal length, but central definition remains good throughout. I have a feeling that this may be due to a field curvature issue, as better results are obtained by focusing near the edge of the frame rather than in the centre. I need to do more testing and use the lens for some practical photography, but this one may well be a keeper! Further testing has confirmed my fear that. at 28mm, the edges are very soft. A pity because at the centre at 28
I'm continuing to search for a half decent walk around lens for my Sony a6500, having tried and discarded the Zeiss and Sony offerings. My latest discovery is a Pentax A 28-80 f3.5-4.5 zoom from the film era. I've had my copy for years, bought second hand it's not in the best of condition, with marks visible on the front element and a general slackness in the zoom helicoid. This is what it looks like on the camera. Be warned, this is a manual focus lens, if that's not your cup of tea, read no further! It's no lightweight being of mixed metal and plastic construction. With adapter it weighs 502 g, but this is appreciably lighter than the Tamron 28-80 that I have also tested. How does it perform, I've not conducted any brick wall tripod tests as yet, but having taken a number of shots with it I am reasonably impressed. Here's an example. It was a muggy, hazy day with poor visibility, but the image quality is OK First of all the overall