Not a lot wrong with that lens/camera combination. The centre line of the chart could/should have been closer to horizontal.

The idea is that the numbers above and below the centre line should fade out of focus at the same rate in both directions with the centre line in sharp focus. It seems they do, so I'd say your hardware is in order. If you are not hitting focus, it's your technique you need to work on.

The blurry ones . . . something moved the tripod/camera/lens or the chart moved.

How did you lose the shadows from the girls chin from pic 2 to 3?

You might try the owner's club. I'm sure there'll be one.

Can't help with the ID, but it sure looks weird.

Where's the original post gone ?

Why sell?

Reflections can be a problem . . .nice article.

Are you sure it's pushed right on to the hotshoe. I'd say if it works on a SF7, it should work on anything Pentax. Have you checked with the manufacturer?

If I didn't already have lenses covering this range, I'd almost be temted to take it off your hands and prove to you once and for all . . . It's not your lenses that are the problem.

But you've heard that one before

Switching brands then? Which one?