I had my first ever go at estimating the magnitude of a couple of bright variable stars this last weekend
I used my modded Canon 300D with a Baader UV/IR filter and took 5 each 30 second images of my targets through my ED80
I also took 5 darks and flats, and pre processed the RAW images and stacked them as I normally would in Deep Sky Stacker.
I then took the image to IRIS and split the channels
Working off the green channel only, I used IRIS to estimate the intensity-ADUs-for the target and 4 to 6 comparison stars (after subtracting background sky intensity)
I used a AAVSO visual chart as I was only testing the approach not trying to collect reportable data just yet.
I then plotted the intensity vs the magnitude for the comparison stars (since this was a visual chart the magnitudes of the comparison stars were only to one decimal place).
the readings appeared reasonably linear, so I fit a best fit line and derived an equation for the line (the R squared was 0.97 and 0.98 respectively)
I then used the measured intensity in ADUs , plugged into the equation derived above to estimate the magnitude of my target star-to one decimal place.
so-is there some fundamental flaw in this approach or is it methodologically sound?
I do not have a mono camera and do not have a V filter. And I did not use a transformational co-efficient-not in the least because I have no idea how to go about calculating one
thanks in advance for any comments or advice. As I said above this is my first attempt at variable star photometry
Narayan