NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Greg Rudzinski
Date: 2016 Jan 27, 09:23 -0800
Bill,
Fixed lens is the best. Zoom is big trouble. 35 mm lens using 10 mega pixel DSLR will give 1' precision. Lunars requires 0.1' precision so a 200mm lens is needed. The calibration of the 35 mm lens can be done working backwards from a known position using a natural or artificial horizon. The artificial horizon will save some time since the Sun is moving through the central field of view at twice the rate. The 200mm lens can be calibrated with a single image of the Sun using the known solar diameter as the yard stick.
Greg Rudzinski
P.S. Lots in the archives on this subject.
From: Bill Lionheart
Date: 2016 Jan 27, 03:54 -0800I wondered if there is any progress on this. I was going to try luna distance with a DSLR to get UTC. With descent image processing can you get better than pixel resolution. What is the trade of between using a fixed focus lens (which is easy to calibrate pixel to angle) and a zoom lens where you can have more pixels per minute of arc but presumably shot needs to include two known stars to calibrate.
