[Rover]

Stopped down means (too) heavy vignetting wide open.

If it's worse that the average fast prime on FF (3.5-4.5 stops), then sure, but 4 stops are nothing out of ordinary. If the vignetting gets better by stopping down, then fine - with some "left-field" lenses, it actually becomes worse as you stop down - say, with Sigma 30/1.4 on APS-H which is usable till about f/5, and then it turns ugly.

 

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In prime land the following are FF, 31/1.8, 35/2.4, 35/2, 43/1.9, 50/1.8, 50/1.4, 50/2.8 (macro), 55/1.4, 77/1.8, 100/2.8 (macro), 200/2.8, 300/4, 560/5.6 - reports are that the 40/2.8 and 70/2.4 will also cover frame.

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I forgot about the 200/2.8, 300/4 and 560/5.6 - these do count as "modern" primes; the others are screw driven and therefore probably due for replacement anyway. I hope for the Pentaxians' sake that Sigma and Tamron get around to introducing some of their fresh stuff for the K mount.

 

Hey, they can rebadge the 35/1.8 and call it a "35/2 replacement". Actually, if they did this to the 15-30 and 24-70, nothing's keeping them from doing this again.