[BAA Comets] DSLR astrometry and photometry

[Roger Dymock]

I am putting together a procedure for using DSLR images for astrometry and
photometry. Two different approaches are being considered;

Procedure 1
Convert RAW images to FITS and extract green channel (Johnson V equiv) (Graham Relf's
GriP - http://www.grelf.net/grip_intro.html)
Calibrate images (AIP4WIN)
Measure images (Astrometrica)

Procedure 2
Convert images to FITS (AIP4WIN)
Calibrate images (AIP4WIN)
Measure images (Astrometrica)

The Citizen Sky/AAVSO method (http://www.citizensky.org/book/export/html/1235) uses
AIP4WIN for processing and measurement but, as a life long user of Astrometrica, I
prefer that software. In the long term I would prefer to use GriP rather than AIP4WIN
for calibration but I have yet to learn how to do that.

Of course before all of this I need to do some work on obtaining images and
calibration frames (best exposure times, ISO settings, etc) and verifying that the
results obtained are as near to Johnson V as makes no difference.

So if anyone out there has done some or all of this I would really welcome your
advice.

Regards

Roger Dymock
Email: roger.dymock at ntlworld.com
Tel: 023 92647986
Skype: rogerdymock67 or
Skype: rjvdymock
MPC Observatory Code: 940
Project Alcock http://www.britastro.org/projectalcock/