From: Terrence Redding <tredding@mac.com>
Date: July 15, 2009 10:33:43 AM MDT
To: Astro_IIDC@yahoogroups.com
Subject: Re: [Astro_IIDC] I think this is my best Jupiter image so far!
Milton, thank you for taking time to write.
For the past year I have been fairly intense in my efforts to do occultations. That process involves a low light analog camera, a KIWI OSD time insertion device that embeds a GPS location and date/time stamp in the recordings. The analog video is typically sent to camcorder for recording. The video is then transferred via Firewire for recording to a PC and saved as a very large AVI file by Movie Maker. Then the video is edited down to small manageable clips and imported into LiMovie where the target is anchored to a comparison star and a photometric light curve is generated.
It would be nice if I could refine the work flow and simplify it and use a Mac in the process.
This past week I decided to commit myself to imaging the planets and that endeavor has exposed me to your software. I am keen to give your software a go. I am reading through the online help file now. It is very well done - an excellent read. Thank you for taking the time to prepare it.
You mentioned photometric time stamp. I wonder if there is a device that would allow me to use GPS time insertion? Dave Herald just released a set of procedures to use highly accurate timing to perform astrometry and the occultation community has started doing just that prior to major event to improve the predicted location of the stars and asteroids for coordinated events.
Just curious.
Again, thank you for the quick response.
Terry - W6LMJ
Terrence R. Redding, Ph.D. RTN
How do amateur astronomers learn?
On Jul 15, 2009, at 11:39 AM, Milton Aupperle wrote:
Hi Terrence;
On 15-Jul-09, at 9:07 AM, Terrence Redding wrote:
Tim, I am not familiar with the camera you used - but assume it is a color firewire camera. I notice they have them from 80 fps down to 7.5 fps. I assume the higher frame rates are needed to freeze the rapid rotation of Jupiter, something like a 9.5 hour day.
Actually, the cameras can run as high as 400 frames per second to 1 hour per frame.
The higher frame rates are primarily used to try to reduce turbulence at long focal lengths and to capture as many frames as possible during periods of good seeing.
But I would appreciate hearing comments on which cameras are best for which applications. I am also interested in inserting a date/time stamp on the individual frames to support photometry. Is there a system for doing that with firewire?
With Astro IIDC, the time stamp is embedded in the movie as a Time Code Track with a UTC time. It can be hidden or shown afterwards in the movie after capture. With QT 7.x, the time code track can be seen while the movie is playing, whether it's hidden or shown.
Astro IIDC uses the time code for when calculating photometric changes too.
Note that the time stamp is not physically embedded In the movie (although it could be shown and then re-compressed to burn it in), as that will cause all sorts of issues when stacking frames.
HTH..
Milton J. Aupperle