Posts: 2
Registered: ‎08-11-2016

GPS AstroTrace problems with Star Trailing Edges & Corners

There has been an ongoing extended discussion across several forums concerning Pentax’s GPS based AstroTracer. It is a great concept! The user interface is improving quite a bit!  The question is the technical implementation. Primarily the problem is the star trailing along the extreme edges and corners.


There has been a lot of speculation as to what the basic cause is (considering a good calibration):

Recently, I came across a Milky Way shot from a K1 using the GPS AstroTrace with an exposure of 3 minutes using a 14mm lens. The results appear to be getting worse to my eye with the advent of the full frame sensor.

The suggested mitigations are:

  • Crop the star trails out loosing a lot of the frame
  • Don’t use wide angle lenses – limit focal lengths to 30mm or longer
  • Don’t exceed 60 second exposures when using AutoTrace
  • Use a physical tracker


These tend to really limit the usefulness of the AutoTrace capability. Could Pentax address this in some manner? Perhaps explain what the implementation is doing and not doing.  AstroTrace is too useful a capability to just not use, especially with the full frame K1.


Posts: 2
Registered: ‎08-11-2016

Re: GPS AstroTrace problems with Star Trailing Edges & Corners

Here is some additioal information on the K1 electronic compass' performance...