Could be an old 6MP Monolta yet!!

And I advised him not to buy any Japanese junk and go for good quality German gear!!

Now we know where they get new hair styles from
Very impressive from a sharpness point of view especially at f/5.6, shows how good the 55-300mm is.

MTF increases don't always translate into sharper pictures, especially on Digital which has it's own resolution limit. It might do on film, but I expect it would be un-noticeable on a lens that isn't a top performer anyway. The filters seem very rare and would probably be expensive being 82mm multi-coated so the best thing is just forget about it. There's probably a dealer somewhere that still has these in stock

£435 was a low price for this lens and in any case there weren't any offers. Pentax will no doubt see that 300mm+ lenses just aren't selling and take this into account when they decide on what new glass to manufacture.

The Tamron SP 500mm F8 mirror lens is SHARPER with the official
UV filter it was part of the design. link

I'm surprised that you haven't had any interest in a superb performing lens like this I still use mine rather than the DA* 300mm because the image is about 11% bigger. Best of Luck on ebay

Dighital?? Must be High Definition Digital

I can imagine an 85mm would just snap in and out of focus better than a 50mm. The sad part is that we are actually seeing f/2.5 not f/1.4 on dighital so you should see the snapping in and out even better on you K cameras

I did mention this in another thread on MF last week.

The diopter adjustment on the K20D at least is far too coarse to get the viewfinder image in focus properly, unless your eyesight just happens to coincide with one of the click stops. Using a Refconverter you have continuous adjustment and can get it spot on especially with 2x magnification.

This shot was taken with the 50mm A f/1.4 at f/2 using the above method and focus is exact to the mmm the ink has actually changed colour at 0mm

Using a Refconverter you can also see that focusing on the screen markings is only approximate.

K20D with Normal Focussing Screen using Refconverter A
100% Crop