Hi, I use the same basic

Forums Meteors LCD Shutter Hi, I use the same basic

Bill Ward

Hi, I use the same basic method with my WATEC’s however when you dig into the numbers even 1/25 sec isn’t fast enough to get the required precision to determine decelerations for orbital corrections. Steve Evans’ paper from 20 years ago (!!!) out lines the requirements nicely. (JBAA Vol 108 4 1998 “Experiments in digital meteor astrometry”) His work then was with his rotating shutter system, which I have and am trying to reinstate, running with three blades giving a chopping interval of ~33.3ms that’s faster than 1/25 sec (40ms) and it still wasn’t enough. He ultimately was working with a 6 blade shutter to give ~16.7ms (Which is the one I’ve been given). Astrometrica is the program he mentions.

The costs are high but not prohibitively so compared to the camera’s your using. Even with the cost of a LCD shutter and function generator as they are at the moment is still ~tenth of a SONY A7SII and if you include include a cheap dslr and lens and you’ll get five systems for the money.  Despite all of the limitations with meteor observing it’s all about sky coverage!

I’ve found a supplier of very cheap LCD shutters and have ordered a couple to experiment with. IF these work then it becomes extremely feasible to have a high speed optical chopper that may yield arcsec precision for less than £20 (if you build a function gen kit from ebay!)

The consumer technology is quite remarkable.