SQM Measurement without a fancy meter

[The Thing]

Hi All,

Just been playing with software and found ASTAP can measure your SQM value from an image. I fed it a single raw sub (important: not stretched or debayered in ASTAP), raw dark and raw flat (all FITS images in my case), solved the image then used the new(ish) [Tools], [SQM report based on an image] function. Mine worked out as 21.85    but then the French have turned of the streetlights and I'm pretty much in the countryside.

Hope that's useful, it means if you have been anywhere e.g. Cairds Farm and you have some subs you can see what the sky was like that night. Now to dig out some old Deep Sky Camp data!

Duncan

[Carole]

I have an App on my phone which will measure SQM.  As I recall it was a free download.

You certainly have lovely dark skies.

Carole   

[The Thing]

An app on your phone? How is it calibrated? All the ones I've ever seen require an external sensor as phone light sensors and cameras aren't up to it. Of course the latest ones might be.

[JohnH]

No idea how accurate it is but I have an app on my iPhone called "Dark Sky Meter" it gave a reading of 19.12 here near Bromley South Station.

[The Thing]

No idea how accurate it is but I have an app on my iPhone called "Dark Sky Meter" it gave a reading of 19.12 here near Bromley South Station.

Was that under the High Street road bridge?

[Carole]

That's the one l have, Dark Sky Meter.