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EQMod - now includes Air Mass

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Chris, once again, has done a great job of improving and enhancing the EQmod software ( for SW Eq. mounts) by adding the calculation of Air mass to the display screen.

Go to the EQMod group and download the latest version V1.27o from the files area.



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It is widely used in photometry and spectroscopy as a key measure of the amount of atmosphere between us (on earth) and the "target object"

Simplistically, the higher the air mass the higher the light loss, which has then to be compensated in your measurements.

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It sounds a very good addition, but i will stick to 800 ISO, 30 seconds unguided, 180 seconds guided and take a chance on the light loss...thats of course if its a AP addition and not purely Spectroscope usage....:)

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The effects of Air mass can be seen in all images....

To image and object say 10 degree above the horizon you are effectively looking through x5.58 the amount of atmosphere you'd have if you imaged above you at the Zenith.

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  • 4 months later...

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