Thursday, January 27, 2011

SALT Pupil Time-Lapse

While taking some out-of-focus images to check on some vignetting issues we thought it might be interesting to take a sequence of such images to track how the segments behave after an alignment is done. The first such sequence was done while observing the star HR 806. A total of 100 images were taken with 0.1 exposure time each and a 30 second delay between each one. Here is the resulting movie:

This particular track didn't allow us to see some parts of the primary so we tried again on a star (HR 1960) that allowed us to track through the center of the primary. We set out to take 200 images (0.5 sec exposure; 30 seconds apart), but the sequence got cut short to 175 when the humidity spiked and forced us to close. Here are the results:


  1. Sheez Deon! At last us engineers who worked on this telescope can see in real life what the vignetting looks like. Very interesting post!