To cut a very long story short; I was searching for reviews of the new Sony A7r camera and stumbled onto a thread where a guy was showing some astro images captured with the Sony mounted on a single arm barn door tracker.
Love at first sight for me.
The tracker is pretty simple to build though some measurements require a high degree of precision, not one of my strengths, but had a go anyway and this is the result. Needs tweaks here and there but is good enough for a test run.
The idea is to align the hinge joining the two boards with the celestial south pole and then turn the CD at precisely one rev per minute to drive the top board (where the camera is mounted) upwards at a rate that will counter the Earth's revolution. A nut is fixed to the CD.
The protractor is to adjust for latitude using an old pan and tilt head I had laying around. This, combined with a compass to locate south is all thats required for polar orientation for wide sky images. So tonight was the first field test and I was greeted with clouds in the south making orientation quite difficult. Grrrr!
The image below is nothing special but shows round stars after my first two minute exposure so I'm bloody excited to put it mildly.
Also the image was captured at 55mm and iso 6400 which is far from ideal, need to shoot much wider and at a much lower iso to control noise. I just wanted to see if the thing works, and it does.
Can't wait to get out into desert country and hopefully capture some milky way exposures. If I can get the exposure times up to five minutes and beyond with accurate tracking the possibilities are endless.
Can't really do deep sky stuff but that's not what I'm chasing at present. The goal is to shoot night landscapes with hopefully a sky full of stars.
Anyway, here's my tracker and first ever astrophotography image, pretty basic but the stars are round (well, nearly!) and that's all I was aiming for tonight.
Love at first sight for me.
The tracker is pretty simple to build though some measurements require a high degree of precision, not one of my strengths, but had a go anyway and this is the result. Needs tweaks here and there but is good enough for a test run.
The idea is to align the hinge joining the two boards with the celestial south pole and then turn the CD at precisely one rev per minute to drive the top board (where the camera is mounted) upwards at a rate that will counter the Earth's revolution. A nut is fixed to the CD.
The protractor is to adjust for latitude using an old pan and tilt head I had laying around. This, combined with a compass to locate south is all thats required for polar orientation for wide sky images. So tonight was the first field test and I was greeted with clouds in the south making orientation quite difficult. Grrrr!
The image below is nothing special but shows round stars after my first two minute exposure so I'm bloody excited to put it mildly.
Also the image was captured at 55mm and iso 6400 which is far from ideal, need to shoot much wider and at a much lower iso to control noise. I just wanted to see if the thing works, and it does.
Can't wait to get out into desert country and hopefully capture some milky way exposures. If I can get the exposure times up to five minutes and beyond with accurate tracking the possibilities are endless.
Can't really do deep sky stuff but that's not what I'm chasing at present. The goal is to shoot night landscapes with hopefully a sky full of stars.
Anyway, here's my tracker and first ever astrophotography image, pretty basic but the stars are round (well, nearly!) and that's all I was aiming for tonight.
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