On a K-5, by the Ephotozine:-http://www.ephotozine.com/article/smc-pentax-da-55-300mm-f-4-5-8-ed-lens-review-16547I think this one generally agrees with the previous lens test by the Photozone, which can be found here:-http://www.photozone.de/pentax/396-pentax_55300_458Related:-Useful Lens Review LinksSearch This Blog for "Lens Test"
