Originally posted by Adam On a cheap one maybe!
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so the 60-250mm isn't a lens that I'd stick on my future Pentax FF.
I'd beg to differ.
One of my new favorites (the 24-70 from Nikon) vignettes 1.55 EV and it is a non issue for me. Film with its gradation often exaggerates the effect.
Moreover, the nice thing is that the DA* 60-250/4 doesn't vignette on FF at the wide angle and is tack-sharp in the center at the long end. Typically, using a zoom at its long end means you will crop the final image a bit anyway.
So, on a 5µm pitch FF Pentax FF, the lens can be used as a 60/4-400/5.6 (in 35mm equivalent terms) with no much compromise. I know of no other lens which can do this.