advice please-using Lee Big Stopper

I have been trying the Lee Big Stopper on my K20D.
It takes a long time to process the image in the camera and I wondered if that is normal and whether more recent models (k5) are quicker.

For example I exposed for 4 minutes at iso 100, DNG format, and it took about 4 minutes for the image to be processed by the camera before I could take another shot.

grateful for any comments

Paul

That is the same with the K5

Yes when you take a long exposure shot (anything more than a second) I think Pentax DSLR cameras then take a second exposure of the same duration with the shutter closed (i.e. a dark frame) and then use that in reducing the noise inherent in the long exposure. Hence the long processing time. It is possible to turn the feature off in the camera menu on the K7/K5 I think by scrolling to 'slow shutter speed NR', but I am not sure whether that is possible in a K20D... suspect not Do you have a manual for the K20D? - the details will be in there; if not then it is probably possible to find a pdf of the manual on the Pentax website.

Cheers

Hi Paul, yes, you can turn off the slow shutter speed noise reduction on the K5, meaning that the camera is ready to take the next exposure pretty much as soon as you close the shutter for the first. Results are pretty good as well, I have not noticed any hot pixel problems.