NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Greg Rudzinski
Date: 2015 Jan 26, 12:22 -0800
The verdict is in with the point and shoot PowerShot camera once again failing badly for practical CN. Several series of calibrations were attempted showing large spreads (30') between sets. This was unexpect because all auto features were turned off and the auto focus was locked at infinity. My guess is that there is slop in the focal length so that every time the camera is turned on there is a slightly different focal length which defeats any efforts to calibrate. So back to the drawing board. There are some new point and shoot cameras that are on the expensive side whicht may have things tightened up enough for CN purposes. The Sony RX100 M3 caught my eye. When the used price on this model drops then I might give it a try.
Greg Rudzinsk
From: Greg Rudzinski
Date: 2015 Jan 7, 11:17 -0800A revisit to my first unsuccessful efforts (8 years or so ago) at point and shoot camera CN using a Canon Powershot 10MP has me thinking that there may be a way to bring this type of affordable camera into the relm of practical CN. The still image settings offer three focus options. The infinity setting is the correct setting that will allow this inexpensive pocket camera to double as a useful sextant. An artifitial horizon will be used for calibration observations to construct a table of minutes of arc per pixel at various pixel counts. Lightroom 5/Paint software works well for processing images and counting pixels. Solar film taped across half the lens does a good job for filtering the Sun.
Greg Rudzinski
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