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DSLR photometry using VPHOT possible ?

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Shishir Deshmukh
DSLR photometry using VPHOT possible ?

Hi All,

I'm a novice to VPhot.  Just wanted to know if:

1) DSLR photometry is possible using VPhot if I process images using IRIS ?

2) Are images to be plate solved before I upload them for photometry ?

Thanks in advance.

David Benn
David Benn's picture
DSLR photometry using VPHOT possible ?

Re: 1), I use IRIS to create calibrated, stellar-registered images with color channels separated, saved as FITS files.

Until recently I was only doing photometry via IRIS too, i.e. extracting instrumental magnitudes then using the ensemble approach with spreadsheet created by Mark Blackford and others (originally Citizen Sky).

Re: 2), more recently I've been going on to use AstroImageJ to plate solve the images before upload to VPHOT.

I also wrote a script (on github; happy to share) to update the FITS header before upload. It also adjusts midpoint time etc, useful even for IRIS-only photometry.

I have not transitioned away from the ensemble/spreadsheet approach yet because for one thing I don't yet have a good quality set of transformation coefficents for my wide-field equipment (Canon 1100D). For another, it works quite well. I'm mostly trying to explore the possibility of reducing the amount of time it takes to get through the processing and improve efficiency.

So, my VPHOT DSLR photometry is still in the experimental stage.

David 

ka5sma
ka5sma's picture
Script for DSLR

Succeeded last night upload a DSLR image to VPHOT...using Pin Point to Plate solve and editing the fits header. Been attempting this for months...

Mike

David Benn
David Benn's picture
Script for DSLR

Hi Mike

Great!

Good to know you edited the FITS header okay. I mentioned a script above but never posted the link; did so in another forum topic recently. Here it is, for your interest:

https://github.com/dbenn/photometry_tools/blob/master/modify-fits-header.py

David

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