Originally posted by schnitzer79 i already have the 18-135mm lens that came with my K-50 and absolutely love it and recently bought a sigma 24-70 f/2.8 for low light photography. although most of my shots are in the 18-135 range, there have been a few times where I needed some extra reach. im not looking for anything too expensive and probably end up buying second hand. ive narrowed it down to these:
Pentax DA 55-300 f4-5.8 (any difference in the WR and non WR apart from the obvious?)
Pentax FA 100-300 f4.7-5.8
Sigma 70-300 f4-5.6 DL Macro
Sigma 70-300 f4-5.6 DG Macro
which one is better in terms of sharpness?
I owned the Sigma 70-300mm DL, and later upgraded to the Tamron 70-300mm. The Tamron was sharper, except for the annoying purple fringing. Then a few years ago, the Tamron died, and I got the cheapest version of the Pentax DAL 55-300mm. No contest! The Pentax is easily better than the Tamron and the Sigma DL. I haven't owned the newer Sigma. These days, I do lots of birding with a K30 and the 55-300mm. Yes I crop, and then apply USM. But it works great. This is a 3:1 crop at 300mm F/8, then resized from 1620x1080 downto 1200x800 for the web. By my math, the image below is is a 1350mm FF equivalent crop.
I also own the SIgma 150-500mm, and there's no doubt its better for the extreme telehioto, but the Pentax 55-300mm is a lot more convenient. I'm tempted to upgrade to the newer weather proof version of the 55-300mm, with quick shift focusing, and slightly better coatings, but I'm good with the lens I have. I usually use a lens hood, which helps with contrast.
Last edited by sheld; 01-28-2014 at 07:12 PM.
Reason: corrected image