K5 lens calibration shifting?

I was doing a shoot in a studio on Saturday and when zooming in to 8X on the face on the rear screen to check focus it didn't look sharp, in the end I went back to using an older body to finish the shoot.
Looking at the K5 images they do not appear as sharp as they have been in the past, they are sharp but not as sharp as they have been (this is at f8 so I didn't think it was a front or back-focussing problem)- I can usually see the goosebumps on the models skin

I did my normal lens calibration procedure and found that it had shifted from -9 previously to -4 now, and also doing some tests with the older body found that the K5 was not as sharp with the identical lens and setup - tripod, cable release, lens fine adjustment calibrated.

Any thoughts on whether this is a lens or body problem? The camera is still in warranty until May so I have a bit of time to try to sort the problem.

All suggestions most welcome.

Perhaps you could start by establishing whether or not every lens had drifted? If that is the case, it may well be the body. If not, then a rogue lens.

There wouldn't be any external reason would there? Temperature or something. I imagine you have thought about that already in any case?

Cold if anything - his models get goosebumps

Sorry no practical suggestions.

Bernard

What about firmware updates?

AFAIK, the AF is linked to colour temperature in the K5. Maybe Pentax made some adjustments in a firmware update? You can always verify the firmware in the EXIF between shots...

It's an interesting possibility that goes to show I better perform an AF adjustment again!

Matt

Thanks all, and Matt and I did think about the colour temperature.

There's not a huge amount of difference, but the older body is marginally sharper with the same lens and setup. I may just be pixel-peeping her though.

More experimentation called for!!!

You could be onto something here Matt.

I purchased my K5 in November. It was a Christmas present, so the only use it got before then was general checking for function and lens setup.

In January after the latest firmware update, like Tim I noticed a lack of sharpness, so I repeated lens calibration, first with a 31Ltd and then later with several other lenses. In all cases the amount of adjustment needed decreased. Before the recalibration the lenses were in the -4 to -9 range , after 0 to -4.

This maybe down to settlement' as something similar did occur with the K10.

Regards - Steve

Thanks for telling me that Steve.

I think some more calibration is called for!!