Dennis
22-07-2007, 05:33 PM
Hello
Previously, using the Mewlon 180, x2 Barlow and DBK ccd camera with frame rates around 15 fps and exposures of 1/15 sec, I have had some difficulty in capturing images of double stars fainter than around 8th magnitude. Since then, I have been experimenting with the M180 and DBK combo at the F12 prime focus of the M180. By extending the exposure to 1 sec and imaging at the prime focus, I have managed to capture stars down to 12.5 magnitude. The improved seeing of 5 to 6/10 and having no Barlow in the image train greatly helped.
So, here is Zeta Cap, aka 34 Cap; Magnitude: 3.74, AB: 3.77+12.5 mag, PA 13° Sep 21.30"
Takahashi Mewlon 180 F12 at Prime Focus with DBK21AF04.AS ccd camera
1116 frames from 1600, 1 sec exposures, Seeing 5 to 6/10
Brisbane, QLD, Australia, 22nd July 2007, 12:27am AEST (GMT+10)
Cheers
Dennis
Previously, using the Mewlon 180, x2 Barlow and DBK ccd camera with frame rates around 15 fps and exposures of 1/15 sec, I have had some difficulty in capturing images of double stars fainter than around 8th magnitude. Since then, I have been experimenting with the M180 and DBK combo at the F12 prime focus of the M180. By extending the exposure to 1 sec and imaging at the prime focus, I have managed to capture stars down to 12.5 magnitude. The improved seeing of 5 to 6/10 and having no Barlow in the image train greatly helped.
So, here is Zeta Cap, aka 34 Cap; Magnitude: 3.74, AB: 3.77+12.5 mag, PA 13° Sep 21.30"
Takahashi Mewlon 180 F12 at Prime Focus with DBK21AF04.AS ccd camera
1116 frames from 1600, 1 sec exposures, Seeing 5 to 6/10
Brisbane, QLD, Australia, 22nd July 2007, 12:27am AEST (GMT+10)
Cheers
Dennis