I found someone on flickr who had done some good work with the astrotracer, and just received a reply with his advice on using it. I'm forwarding the email. It also looks like the deep sky stacker program might be handy for people who do other night photography too.
Hi Larry, Apologies for the late reply here.. I've only used it a few times myself, due to time as well as the monsoon season in Arizona (cloudy most nights through Sept) You need some sort of remote and or cable release The time the astrotracer shows is the max time you can expose for without blurring. Focusing at night (manual) kinda sucks. It's better before hand to take the lenses you plan on using and mark where 'infinity' is during the daylight. That's the only way you can get sharp pictures, otherwise it's kinda just luck and guesswork.. or having some sort of really bright object to focus on in the EVF (like one of the planets.. since typically you want to be doing this with little to no moon, to limit light pollution) Anything over 300mm focal length.. I'd say forget it... I'd like to see this become a poor mans telescope, but it just aint happening :) Find a windows PC and download/use Deep Sky Stacker (DSS) google it to find out more. That program is pretty amazing! You take 3-20 exposures (or more) then shoot one with the lens cap on (to get the noise profile of the CCD for that night.. as conditions can vary) The K-5 has a setting that causes it to take a 'dark' frame for every other exposure you shoot. It's not obviously named.. I found it in either the astrophotography forums and or the pentax forums. If you dont turn this off, you shoot say a 1-3 min exposure.. then the camera immediately takes a matching 'dark' frame. Turn this off.. no need to do this, as you only need one dark frame for DSS Throw them all into that program, the computer chews on them for a bit, then spits out a decent file that you can manipulate in Photoshop. That is what I did with the shots on my photostream. Definitely a work in progress.. just havent had the time as of late with holidays, work and kids activities to spend more time on this :( -- Larry Colen [email protected] sent from i4est -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
