wide field colour stellar photometry

[nytecam]

The pic belows shows an experiment two summers back that may be of interest. It's a single 10s exp unfiltered shot of the Double Cluster In Perseus via My 30cm SCT and SX one-shot-colour Lodestar-C cam.

I used the camera's s/ware to do a red/blue offset* into a colour separation and circled in blue some stars with blue excess and in red with red excess from which differencial photometry may be possible to get a colour index on the stars eg a crude form of spectroscopy:hello2: I've reversed the luminance so sky is a white background!

Any thoughts?

ps: the RGB pixel offset* in the SX s/ware designed primarily for correcting large scale planetary images distorted by atmospheric refraction.

[FraserClarke]

Nice image to show the effect, but I think to get actual measurements you'd be better just measuring the three colours, rather than spreading them out like this. In the core you can already see some objects starting to overlap each other where they are spread out.

I would have thought the main problem would be working out the filter profiles, and hence transforming the colours you measure with this camera to a standard system. Should be possible with enough calibration stars (stars with known colour) though.