Ah well, its back to leaving on autofocus, or just keeping the 28mm SMC on!
Thanks to all for your info

Arrived at high point near Clee Hill (Titterstone) yesterday just as storm was approaching. Followed my old film camera practice of taking a few snaps quickly in case storm arrived too fast to set up properly (it did!) Usual practice is - onto manual, check exposure, set focus to infinity (ie turn focus ring to max) and off we go.

Disaaster! - image quality awful!

So I did some tests, the upshot of which is that if I point at a distant object (block of flats) and take picture with focus set to infinity, focus set to recommended distance, then autofocus, the results are acceptably sharp from the auto and recommended focus shots, but everything - and I mean from 20 feet away into the distance- is blurred when the focus ring is turned to its full extent! Tried again with shake reduction switched off, same result. All on a tripod of course.

Similar tests (infinity v. recommended focus) using older 200mm F4 and 28-80 lens from MZ5N did not show this trait (and gave sharper images anyway).

Lens at fault is the 18-55 DAL 3.5-5.6.

Question 1)Do I have a faulty 18-55 lens which just produces rubbish when the focussing ring is turned to its fullest extent, or is there something I should know?

Question 2)Can anyone recommend a better quality replacement, preferably that does not have this trait?

I have a KR and I have used Video with a older SMC 200mm F4 fixed-length telephoto, which as I recollect I bought maybe 25 - 30 years ago!
What you can do of course is take your lens into the shop and ask to try it.

2x Teleconverter - used it twice many years ago then just never bothered, recently sold it on Ebay.

I've used an MZ5n for a few years now, allows fully automatic exposure and focussing at one end of the scale, and fully manual at the other. It's also very light.

Put on an old Pentax manual lens, put it into autofocus mode, point at the subject and hold the shutter open - shutter won't fire until subject comes into focus. Very useful.

Only problem is the spring goes on the pop-up flash!

I'm just going digital, and not sure yet if I'm going to sell my body (the MZ5N that is!), but let me know if you are interested.:

I always get my film from 7dayshop.com, worth a look