Sunday, 5 July 2009

First webcam image through telescope: the moon in bad skies.

Last night I reconfigured (cobbled) a webcam to hook up to the 10" dobsonian. All I had to do was remove the lens and then find some way of fixing it in place of the eyepeice. Turns out a sligtly modified 35mm film case works well. Amazingly, the focal plane lay well within the normal range of the focusser, so things were pretty straight-forward and stable. The only issue is that the CCD in the webcam is tiny, so the images are very zoomed.

Features on the surface stay in the field of view for about 45 seconds. The earth rotates at 360 degs/24 hours => 1/4 degee per minute. This makes the FOV is about 0.2 degrees, pretty narrow. With the barlow, I can only make that narrower.

Being a rubbish old webcam, literally from a skip, it is only 640 x 480. Am now playing with the awesome-looking RegiStax to see if multiple images will get better quality.

Posted via email from Graham's posterous

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