Originally posted by sindbad1 Hi, I'm looking for a table with maximum tracking/expoure times for the astrotracer in pentax K-3 oder K-3 II. I couldn't find it on ricoh's website. Does anyone have a link?
Tom
On an APS-C sensor camera (K50, K3, etc) the recommended exposure time is 360 divided by the focal length of the lens. So for a 50mm lens, it would be 360/50 = 7.2 seconds. With the GPS attached and in astrotracer mode, you can go longer than the recommended time....around 20 seconds to about 4 minutes for some reports depending on focal length (exposure time inversely proportional to FL).
---------- Post added 09-21-15 at 02:22 PM ----------
Originally posted by interested_observer Here is a paper that presents stacking images - without tracking.
Thanks. My last session was a bust. I don't think I aligned the mini-equatorial mount correctly (latitude setting as well as polar alignment). The small mount did not have a polar alignment scope and I had to eyeball it with the camera on the mount (note to self: not a good idea). Also, the latitude setting scale came off so I glued it back - I must not not done it correctly.
Sigh.
I'll be going back in a week or so lugging the larger equatorial mount AND the telescope (it has a polar alignment scope on it, and I just bought a dual-axis motor) with the T-mount adapter. Milky Way is essentially gone for the season (per your earlier posting) but I'll try to get some DSOs from the Messier catalog.
Last edited by realitarian; 09-21-2015 at 11:23 AM.