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View Full Version : Night timelapse video of stars



BobDiaz
03-15-2010, 10:53 PM
I'm really impressed with what the HMC40 can do. Here's a simple test video shot tonight. It's a timelapse video of the stars in the night sky. The settings are: 1 frame every 10 seconds, 1/2 a second exposure, and +24dB Gain. The 1080/24p video was reduced to 640x480 to help reduce the impact of grain. Pity I'm NOT on the farm in Idaho, the light from LA is showing in my video.

http://vimeo.com/10198498


It's getting late, so I'll have to wait for another clear night to try shooting the same shot with my wide angle lens.


Bob Diaz

David W. Richardson
03-16-2010, 12:55 AM
Well now that's darned impressive Bob. Nice job!

Bic Parker
03-16-2010, 07:46 PM
Bob,
well done. I am doing a lot of shooting at a west Texas observatory/astronomy campus where I also do a lot of observing and imaging (astrophotography). I haven't tried the time lapse at night yet (have mostly been doing IR), but a lot of us have done time lapses with DSLR's, which will obviously get a whole lot deeper into the sky. But this might be good for getting the brighter stars and some constellations (I was able to easily pick out Orion, a bit of Lepus, and Canis Major in your shot).

The real trick with shooting stars is to get a good infinity focus so they are pinpoint.

My only caution with the wide angle is that you will probably get some coma and definitely some chromatic aberration. The easy solution to this is to zoom in a bit or stop down the edges (an old astronomy trick that effectively increases the focal ratio and brings the colors and off axis focus a bit closer to the tolerance levels). The wide angle should bring in dimmer stars, though, since it will increase the aperture by about 20mm to around 62mm (which should gain about 1/2 a magnitude at those apertures).

Drew Ott
03-17-2010, 12:08 AM
Bob,
well done. I am doing a lot of shooting at a west Texas observatory/astronomy campus where I also do a lot of observing and imaging (astrophotography). I haven't tried the time lapse at night yet (have mostly been doing IR), but a lot of us have done time lapses with DSLR's, which will obviously get a whole lot deeper into the sky. But this might be good for getting the brighter stars and some constellations (I was able to easily pick out Orion, a bit of Lepus, and Canis Major in your shot).

The McDonald observatory? I was there about 4 days ago shooting timelapse. I wish I knew some DVXuesrs were out there.

BobDiaz
03-17-2010, 10:30 AM
For getting the stars, I wish the camera has a bit longer exposure time with time lapse, like 5 or 10 seconds of exposure. As it stands, I can get the brighter stars, but the dim stars are a bit out of my reach.

When shooting stars, I always switch to MF by pressing and holding the Focus button (focus = infinity).

I still want to drive up the hill to the south of my home and shoot toward the North Star. The only issue is that North is directly where most of LA is and the lights are going to wash out my shot. Still it might make an interesting shot to see part of LA with the stars in the background turning around the North Star.



Bob Diaz

Bic Parker
03-18-2010, 07:36 PM
The McDonald observatory? I was there about 4 days ago shooting timelapse. I wish I knew some DVXuesrs were out there.

I go out to Fort Davis pretty often (of course, I will be there for the Texas Star Party in May, as I am every year!), but the one I am talking about here is the Comanche Springs Astronomy Campus owned by the Three Rivers Foundation. We have about 6 domes, a rolloff with a 30" (we have a total of 3 30" scopes) and several other Obsessions and other scopes there.