10 Darks or more

Discussion of using SharpCap for Deep Sky Imaging
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Carlesa25
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Joined: Mon Sep 10, 2018 1:25 pm

10 Darks or more

#1

Post by Carlesa25 »

Hello: It is advisable to make a Dark Master with more than 10 shots ... 20 for example, there is some real improvement.
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admin
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Re: 10 Darks or more

#2

Post by admin »

Hi,

the noise in the master dark goes down as the square root of the number of frames, so

10 frames reduces the noise by about a factor of 3
20 frames by a factor of about 4.5
50 frames by a factor of 7
100 frames by a factor of 10

so, the more the better, but it doesn't take long for the diminishing returns to kick in meaning that 20-30 is probably about as many as you want.

cheers,

Robin
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turfpit
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Re: 10 Darks or more

#3

Post by turfpit »

I use 50 darks these days but you will find a wide variety of opinions on this.

50 is a good trade-off for time versus quality based on Robin's figures.

The key to quality is temperature matching lights and darks.
See Brian's post viewtopic.php?f=16&t=1090

A couple of my images with 50 darks applied: 50 minutes of dark collection for these images.

Dave
Carlesa25
Posts: 16
Joined: Mon Sep 10, 2018 1:25 pm

Re: 10 Darks or more

#4

Post by Carlesa25 »

Hello: Thanks for the explanations, understood. Greetings.
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