I now have very approximate figures for the Quantum Efficiency of my modified Canon EOS 350D. They are as follows:
H-alpha 17-21%
Green 33-43% (average over G transmission band)
Blue 25-35% (average over B transmission band)
My methodolology was as follows:
I have a 5 minute RGB image of the Running Man Nebula taken with the Canon on the C11
I have 5 minute R, G & B images of the Running Man Nebula taken with my free hour on LightBuckets back in February.
The LightBuckets image was taken with an SBIG STL11000M camera on a 20" RCOS Ritchey Chretian at F8.1
The Kodak chip used in the SBIG has published QE as follows:
H-alpha 30%
Green 50%
Blue 48%
I therefore took the ratios of the ADUs in one image with the ADUs in the other image but adjusted for the following differences:
SBIG Canon
Gain 0.8e/ADU 1.1e/ADU(ISO 800)
F-ratio 8.1 6.3
Pixel 9um 6.4um
My final QE figures are broadly in line with those on Terry Lovejoy's site for a different camera - the EOS300D:
http://www.pbase.com/terrylovejoy/quantum_efficiency_of_the_300d
My previous comparison of the EOS300D and EOS350D showed that the CCDs were broadly similar in terms of QE except that the 350D was 10% more responsive in the green and 10% less responsive in H-alpha and OIII:
300d vs 350D: http://forum.orpington-astronomy.org.uk/index.php?topic=3582
Mark
I'm new to imaging and all I can say is
:o
si
Don't worry about it, most of that went over my head too.
If it's any consolation, most of Mike's posts on the High Altitude Balloon project go straight over my head as well :-)
I have been following that too :o :o :o
All i know it will be a laugh watching a 8ft ballon fly up from a campsite near Tenterden with a camera and mobile phone attached to it with a piece of string. :lol: To take pictures of the overcast sky of the UK.
(http://www.stuffintheair.com/images/Katrina.JPG)
Surely there are easier ways to get rid of these items, maybe ebay :lol:
si