Sedili Time Lapse

jiahao1986 · Post by **jiahao1986** » Sun Aug 07, 2011 9:44 pm

Gary wrote:Beautiful time-lapse! Give me Milky Way skies + some haze + some light dome anytime over observing in cloudy Singapore right inside the light dome! lol

Looking forward to time-lapse with panning in your future attempts. Keep up the good work!

Thanks Gary. Actually I could've applied some panning with my portable EQ mount. But the mount was polar aligned and reserved for some other imaging plans so didn't use it for panning. Worse still the sky clouded out at around 3am and I packed up everything, after which the sky cleared up again...

jimmyleong · Post by **jimmyleong** » Sun Aug 07, 2011 10:17 pm

thats nice.... how did you do that? is there a software or what?

jiahao1986 · Post by **jiahao1986** » Sun Aug 07, 2011 10:25 pm

jimmyleong wrote:thats nice.... how did you do that? is there a software or what?

Hi Jimmy,

This video consists of 218 images taken with my camera. I set the camera to continuously shoot 30s exposures.

In the post processing I used Photoshop to batch resize the photos to reduce the processing load when rendering the video. Then I used Quicktime Pro to render all these single images (frames) into a 15fps video. The whole thing is acutually quite easy.

Tachyon · Post by **Tachyon** » Sun Aug 07, 2011 11:00 pm

Very smooth video!

Have you tried to lower the ISO to 1600 to reduce the light pollution?

jiahao1986 · Post by **jiahao1986** » Mon Aug 08, 2011 12:04 am

Tachyon wrote:Very smooth video!

Have you tried to lower the ISO to 1600 to reduce the light pollution?

Hey dude,

Actually I intended to capture some meteors, thus blew up the ISO to 3200 and kept shooting at f/2.8. Indeed one very long meteor is captured in one frame. You can watch the highest resolution version of the video on Youtube and pay close attention at around the 4th second. There's a very long green meteor on the upper left.

If you can't see, then can try the version on flickr. Flickr seems to encode the video better...

http://www.flickr.com/photos/34615469@N04/6017542693/

jimmyleong · Post by **jimmyleong** » Mon Aug 08, 2011 12:20 am

guess 30secs for f2.8 is kind of max for not getting star trail right?

Post by **rcj** » Mon Aug 08, 2011 12:43 am

i like this video very much, Jia Hao! thks for sharing!

jiahao1986 · Post by **jiahao1986** » Mon Aug 08, 2011 12:48 am

jimmyleong wrote:guess 30secs for f2.8 is kind of max for not getting star trail right?

Hi Jimmy,

There's the following thread started by weixing providing a guide for deciding the correct exposures. For practical modern mega-mega-pixel cameras to avoid trails at 100% zoom, you probably will need to reduce the numbers by at least half.

http://www.singastro.org/viewtopic.php?t=3800

Actually when I zoom to 100% on the single frames which are taken with 15mm focal length at 30s exposure, stars near the celestial euqator show obvious trails already...

jiahao1986 · Post by **jiahao1986** » Mon Aug 08, 2011 12:50 am

rcj wrote:i like this video very much, Jia Hao! thks for sharing!

Thanks Remus!

starfinder · Post by **starfinder** » Mon Aug 08, 2011 11:57 am

Thanks for sharing the info Jiahao!

To add a point on Jimmy's question, one would usually use a handheld device called an intervalometer. This would be set to make the dSLR take multiple photos at particular intervals, eg one 30s shot, followed by a 5 sec pause, then another shot, to be repeated X number of times. I got one last year but so far hav only taken daytime timelapse photos of clouds and sunsets.

You could buy these from camera shops, suited to your camera brand. I think around $80 to $130. Some higher end cameras hav the interval feature built-in so the separate device isnt necessary.