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Old 16-01-2015, 08:16 PM
Fred_76
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Fred_76 is offline
 
Join Date: Dec 2014
Location: Le Havre
Posts: 16
I tried the formula for the C/2014 Q2 Lovejoy comet.

My equipment is a Canon 500D (pixel size = 4.7 µm) with a Tamron 135 mm F/2.8 lens open at F/4. The comet, yesterday was at 13° declination.

The formula (in blue below) gives :

t = 25x(4.7+4)/[135xcos(13°)]=1.7s rounded to 2s

The stacking of 67 photos with 2 s exposures gives the following result (not enough to correctly see the comet but enough to imagine it) :

http://www.sahavre.fr/forum/download...=949&mode=view

The stars are round !
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