FWHM in live stack vs focus tool

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chongo228
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FWHM in live stack vs focus tool

#1

Post by chongo228 »

Does the live stack FWHM tab measure the stars the same way as the FWHM multi-star tool?

Currently I autofocus every 45 minutes or so and I'm wondering if I can rely on the FWHM tab to tell me if I can wait longer. If my score in the focus tool is a 2.6 would the FWHM tab also show the same image as a 2.6? Are they using the same scale and programming to measure the stars?
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admin
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Re: FWHM in live stack vs focus tool

#2

Post by admin »

Hi,

for the multi-star FWHM focusing, SharpCap deliberately excludes stars that are saturated or close to saturation as those may give somewhat incorrect FWHM values. For live stacking, all star FWHM values are used (after all, potentially there may only be saturated stars detected when live stacking).

This will mean that you see different numbers, but the values you see during live stacking should still change in the right way (ie get larger) if the focus drifts out.

cheers,

Robin
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