hi people
thanks for your answers,
yes, i tried different cards, happens as well
yes what i'm having is exactly what's described in
K20D has VPN under Cold Temperature?
yes it might be only in cold temperatures, but please pentax, -5celcuis is not that cold
and that camera should work without any problems at that temperature and even colder
otherwise why would i have bought a weather proof dust sealed camera if not for outdoors?
yes it is also called banding in some post
thought it seems different than what dpreview found in banding at high iso
however, it might be correlated to that problem too, it does seem this problem happens on my k20. yet, it is not as obvious.
the banding i get are systematic vertical "whitened" stripes about 4 pixels wide (2 whitened 2 normal or perhaps darkened), over all the picture
i cant reproduce the problem systematically though
it happens whit cold temperature, but randomly, perhaps 10% of my images if not more
*Pentax you better replace my camera right away*