Author Topic: Calibration Frames  (Read 3376 times)

Offline John_Gill

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Calibration Frames
« on: 2018 July 03 23:40:11 »
Hi,

When taking calibration frames (flats, darks and bias) should the dew shield on the scope be removed or left in place.

Look up
John
APM 107/700 apo on CGX mount
ZWO Optics - Autoguiding
ZWO1600mm and filters
... when there are no clouds ...

Offline msmythers

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Re: Calibration Frames
« Reply #1 on: 2018 July 04 00:09:14 »
John

Flats are all about optics errors. Since the dew shield is in the optics path it should be included for flats. While unlikely it's possible to have a reflection or some other odd anomaly due to a dew shield.

Bias and darks have nothing to do with optics and everything to do with camera characteristics. The dew shield will not have an effect on or off.


Mike

Offline John_Gill

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Re: Calibration Frames
« Reply #2 on: 2018 July 04 00:22:46 »
Thanks Mike, I have been doing it right but just needed to check.
APM 107/700 apo on CGX mount
ZWO Optics - Autoguiding
ZWO1600mm and filters
... when there are no clouds ...