Originally posted by Just1MoreDave The Pentax-M lens will be wide open in any mode except for M. M won't work because none of the settings will change. You might want to stop down a little bit, like f2 or so, just because that will improve the individual images. You could do this by not quite mounting the lens fully. About 10 degrees short of locking, the lens aperture lever won't engage with the camera's arm any more, so you can set any aperture you want on the lens aperture ring. It is not quite as sketchy as it sounds.
Exposure is going to be the hard part. The camera will try to make everything the same brightness in any automatic mode, but you want it to look darker at night. You probably don't want auto white balance. If you shoot all individual RAW images, you can adjust them to get a better flow between dusk and darkness.
Night sky RAW photos will have smaller files than usual, and the K30 does take SDXC cards so that is not a limiting factor. The internal interval timer only does 999 shots; that may be a problem for the best flow. The K30 has a socket for an external timer. Battery life is going to be a problem.
It would be nice to have three identical nights in a row or break the shoot up into three segments. In the break, swap batteries and adjust settings. Maybe time the breaks so they happen during complete darkness. Lots of experimenting!
Thanks for the sound advice! I've decided I need a little more equipment, and experience with this camera, before I do day to night timelapse. I did do a starry sky thing in my backyard, though, even though the light pollution here is horrid. I just had to try it. I'll post the results here after I'm done with it. I do have one question for you, however. I don't understand what you mean when you say my M lens will only work wide open? The aperture ring works perfectly fine while on my K-30.
EDIT: Oh, I just realized I lied to you guys, lol. I'm using my Pentax-M 28mm f/3.5...my mistake