Many thanks to Chris for his patience and help regards pm's and payment. All in all a pleasant experience. John

Hi, interested in lens, don,t know how to pm!

Thanks for further ideas, I agree in that I think it is diffraction causing the problem. The camera was mounted on tripod, in focus according to my eye and the green hexagon, mirror up using remote. When weather/light conditions improve I will do an outdoor set-up and see what the results are. Don't want to get to "geeky" (is that a word?) about it, just niggles me.
Regards J.

Hi again, update on my focusing question. A very senior moment may have occured, I have been focusing through a conservatory window (DOUBLE GLAZED) would this have upset the K5 focus? Expecting replies along the lines of "of course it would you idiot" !

Thanks guys for your ideas, back to the drawing board. If I resolve this (or when) I will post again, May assist someone later.
Regards.
J.

Hello all from sunny? Hampshire, from my user name you may guess that I am a long time Takumar/Pentax fan. Starting with a Spotmatic through to K1000 and on to the LX stopping for a brief flirtation with a Bronica ETRSi, then a Nikon FM2n then because I had kept my old Taks I ventured into the digital world with a K100D which I still use with a Tak 300mm f.4 attached. I am retired now and with a gratuity from HM have treated myself to a pair of K5's (with the wifes permission of course) so yes, I am a lucky guy and the Pentax affair goes on. Regards to you all, and as someone once said "wait for that special moment", or words to that effect.

Hi all, a conundrum. Firstly I have been taking photographs since the 60's so I have learnt a little bit. I own a Pentax K100D also a K5, with a wide variety of lens both manual and AF. On the K100D I have used for many years with good success a SMC PK Manual 300mm f.4, it works very well. On the K5 using the correct settings for manual, the results are dismally out of focus, I have tried everything. I am lucky in that I also own the 2.4 70mm Limited, stunning results. At the other end of the spectrum I use a 50mm SMC 1.7 Manual focus, again results are stunning, why will the 300mm focus on one body and not the other? Any advice/tips really would be appreciated to preserve my sanity,