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When is DSLR data really transformed?

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mikemolecule's picture
When is DSLR data really transformed?

Greetings, I am new to DSLR photometry. I have read the AAVSO's Manual on DSLR Observing. It is quite good, but I am confused on one point. It describes using the following equation as the way to transform your measurements to standard V-band:   Vtgt = Vcomp + [Gtgt-Gcomp] + T[CItgt-CIcomp] (page 63). This makes perfect sense to me. However, later (page 69) when describing how to submit your data to the AAVSO, it says that if you used the above equation, then your data has not been transformed, and you should check "TG" as your filter.  Is this a mistake?  Can I use the above equation for transforming my data? If not, then please let me know what additional steps I need to do to transform my DSLR data. (from what I have read transformed data seems to be the most useful) Thanks.



HBB's picture
Transformation of DSLR

I remember when we took the DSLR photometry course, some typos in this section were noted.

If you are using the equation that you noted (equation 4) or equation 7, then you would report filter as Johnson V and report your observations as transformed.  If you use equation 3, then the filter would be TG and you would not check the transformation box.

If you are using a wide field of view, then you can use the beginning or intermediate spreadsheets for transforming.

Barbara (HBB)

mikemolecule's picture

Thank you very much! Your input is greatly appreciated. 

Mark Blackford
Mark Blackford's picture
DSLR manual V1.3

Hi Mike,

as Barbara mentioned, a number of typos were found in version 1.3 of the manual during the first two times the CHOICE DSLR course was run.

I'm nearly finished a fairly major update of the manual which I plan to use in the next CHOICE DSLR course in November/December. After the course I'll fix any error/typos the students find then AAVSO will release it for general distribution. Cheers,


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