Thanks so much for your time and help. Your idea about the use of the adjustment brush with higher magnification makes sense.
I have I believe sorted this problem in the camera - seems I need to adjust by +9.
Cheers
Keith

David,
Thank you for that information. Must say that I prefer to use AFS to MF, but Im glad of any measure that assists.
I'm currently identifying what calibration appears to be best (its not easy!) and I'm at the + end of the scale at about 9 or 10. My eyes are good as I don't wear glasses but even so I think I need a better pair! No doubt the resulting photos should get the answer from other folks.
Cheers
Keith

Smeggypants - seems so simple and don't know how I didn't discover this - my setting was on OFF! Allow me to say it - Idiot!
I have read up in the manual and will test at the first opportunity, but just one more thing please - will this also automatically correct when using the MF setting?

Thanks for explaining about Lightroom at 11:1 magnification, but then what is the largest magnification that one should use please?

Hi Ohawa,

I had this problem with my K5. I bought it in March 2011 and there was no problem till August 2011 while I was recording travel well away from home - as you know it is very annoying. It was under warranty and I sent it back to the dealer. The camera was replaced, so I suggest that you do likewise. Good luck!

I bought a Pentax K5 with a Sigma DC 18-200, 3.5 - 6.3 lens in August 2011 and just used it to record travel etc and the photos looked fine. However, I was not a serious photographer and I did not enlarge photos much to check on focus. Occasionally I noticed that much enlarged photos were not focused but just reflected that any photo "over enlarged" would not remain in focus. I'm not sure now whether that is true after having submitted older and recent photos to a stock agency and to my consternation had them report that none of them were in focus.
Since then I have tried to take photos on AFS and MF and find that they are indeed blurred when magnified in Lightroom to 1:1 and above.
My questions are: to what degree of magnification should a well focused shot with my camera and lens still be in focus? I would like to think that it would be to Lightroom's 11:1 magnification and wonder whether its the camera or the lens or the combination of both at fault?

Oops!

http://www.timeanddate.com/eclipse/lunar/2014-april-15

Thank you Galoot - that goes part of the way.
Here is a "map" showing where this event can/cannot be seen throughout the world.

Hi - I'm new so please tell me if this is posted in the wrong place...or maybe advise a better place. Thanks!

On 15/4/2014 there will be a blood moon (in Australia anyway,)(a rare event - worth Googling)and naturally I want the best photos possible. Its important to recognise that the moon being red will produce lower light quite different to "normal" moon shots.
My equipment is listed below and Im planning to lift the mirror, use no filters and of course use the tripod. I would like to use ISO 100 - unless otherwise advised.
I would be grateful for assistance with camera settings to obtain moonshine on water, a landscape including the moon and of course to just have close up moon shots.
Your advice will be most welcome.

Thanks McGregNi!

I am relieved to know that opening a jpg causes no deterioration - thanks to gwing and johnriley. I read a post where some-one led me up the garden path on that issue.
McGregNi: Thank you - I use Lightroom and being fairly new to it Im a bit lost about saving as a TIFF and flattening/dulicating layers. I shall investigate.....
I don't know about all stock agencies but know that Shutterstock only want jpgs, so I aim to shoot RAW and then convert.
I am fine as regards composition - a look at photos in stock agencies is a good guide - its more the technical aspects. I must say that there are some great videos on the internet for training in Lightroom and again thanks for your offer but videos are the way to go for me (I'm more a visual type )- unless I cant find the specific answer.