Sensor Analysis on CCD

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barnold84
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Joined: Thu Apr 08, 2021 6:44 am

Sensor Analysis on CCD

#1

Post by barnold84 »

Hi,

I'm wondering if there's a point in doing a sensor analysis on a CCD camera?
These cameras (an Atik 428EXm specifically) usually don't have gain and/or offset settings (at least so it appears to me). Therefore, I would assume I could simply use the values given by the manufacturer for exposure calculations?

Björn
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admin
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Re: Sensor Analysis on CCD

#2

Post by admin »

Hi Bjorn,

absolutely, although for a CCD the values that you get from the manufacturer tend to be a bit of a range, so you might want to pin down where your specific camera comes in that range.

Of course there are people who just can't resist measuring things for themselves just to check that it matches up with the manufaturer data :)

cheers,

Robin
barnold84
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Re: Sensor Analysis on CCD

#3

Post by barnold84 »

Hi Robin,

Thank you for your reply!

Since there is no gain adjustment, I assume that the sensor analysis will report only a single line with the measured values of read noise, FWD?

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Re: Sensor Analysis on CCD

#4

Post by admin »

Hi Bjorn, yes, that's correct - you will just get one value.

cheers,

Robin
Ana
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Re: Sensor Analysis on CCD

#5

Post by Ana »

Hi Robin,
Sensor analysis for ATIK 460 EX indeed shows one line. But, camera control still has options for gain increase. Is it real gain increase? What does it give? Will we’ll depth drop with gain increase? If yes, how to calculate it?
Thanks a lot!
Ana
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Re: Sensor Analysis on CCD

#6

Post by admin »

Hi Ana,

the 460EX is a CCD camera, so it does not have a true gain adjustment, so one row in the analysis results is what you would expect.

SharpCap adds a digital gain control for Atik cameras with no gain adjustment to allow you to brighten the image without needing long exposures - this works by simply increasing all pixel values by a multiplier controlled by the digital gain control. Digital gain does not affect the sensor readout (e/ADU, read noise), so it doesn't get any extra lines in the analysis results.

cheers,

Robin
Ana
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Re: Sensor Analysis on CCD

#7

Post by Ana »

Hi Robin,
Thanks a lot for clarification.
All the best!

Ana
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