NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Greg Rudzinski
Date: 2015 Jul 2, 21:59 -0700
Here is the first look at a Canon G9 calibration trial using a natural horizon from a height of eye of 7 ft. The Sun is filtered by solar film and is stretched by lens distortion. The horizon is curved by distortion at the bottom. Pixels 2989 x .83' = 2480.9' = 41° 20.9' - 17.3' corr. = 41° 3.6' Hs
Greg Rudzinski
From: Greg Rudzinski
Date: 2015 Jun 30, 09:40 -0700A first trial to calibrate the Canon G9 powershot point and shoot camera was done this morning using an artificial horizon and double linear polarizers in front of the objective wide angle lens. The first images show that there is significant distortion at the top edge of the field vs. the bottom. Comparing two separate calibrations shows that the measured angle is repeatable ( .83' x 3352px = 46° 22.2' - 35.6' corr. {at} 3352px = Hs 45° 46.6' .83' x 3341px = 46° 13.0' - 35.2' corr. {at} 3341px ). Settings ISO 100, 1/500 sec, f 8, infinite focus. The infinite focus problem has been resolved by turning off the Safety MF function in the main menu (how was I suppose to know that :0 Thanks for that tip Peter :). The C1 and C2 custom settings work great so that when calibrations are continued all the settings will be saved.
This just might work. It is very difficult to do though so I will recommend saving up and getting a DSLR with fixed prime lenses for anyone thinking about doing camera CN. Image quality and f stop range is much better on the DSLR as well as no viewfinder parallax.
Greg Rudzinski
Attached File:
(cal-test-1-G9.jpg: Open and save)
