[BAA Comets] DSLR astrometry and photometry

[Roger Dymock]

Dear all,

As you may know the CCD astrometry and photometry process does not produce accurate total magnitudes
for large, bright comets. DSLR imaging may provide the answer and a draft procedure for analysing
DSLR images can now be found at
http://www.britastro.org/projectalcock/DSLR%20astrometry%20and%20photometry.htm 

I experimented with Astrometrica and AIP4WIN for some months but to no avail (they do not allow for
the large apertures required). I noticed that one of the observers inputting to COBS was using a
DSLR camera and he put me on to Iris which appears to do the trick.

Iris could be improved I feel if it allowed access to online catalogues and allowed one to set max
and min magnitudes to rule out any saturated stars. I have contacted Christian Buil but have not yet
had an answer.

Would appreciate other observers giving this a try or sending me calibrated DSLR images for me to
work through. Of course I would also like your comments on this procedure.

Happy New Year

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/