Sensor Analysis

Somewhere to ask questions about the best way to use SharpCap
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miketurner
Posts: 3
Joined: Sat Nov 14, 2020 3:46 pm

Sensor Analysis

#1

Post by miketurner »

When trying to run Sensor Analysis, the exposure keep moving to 234ms and then it tells me the exposure is too short and to make it between 0.26 and 2sec. I move it or I adjust the window bigger or smaller, but it goes right back to 0.234 again. I've tried everything I know how to do, but it won't cooperate. More than likely it's me not knowing what I should do. Can someone give me a hint?

Thanks,
Mike
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admin
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Re: Sensor Analysis

#2

Post by admin »

Hi Mike,

basically you have to try to reduce the light level – at this stage in the analysis, SharpCap is basically automatically adjusting the exposure to try to get the brightness level that it wants (about 65% of full brightness). It also wants to get an exposure time of more than 260 ms in order to give it enough scope to adjust the exposure later when measuring at different gain values. If you reduce the brightness of the light falling on the sensor enough then SharpCap will spot this and start to increase the exposure past the 260 ms point at which point you will be able to proceed with the analysis.

If you are running the analysis with the camera attached to the telescope then something as simple as putting a piece of A4 White Paper over the end of the telescope may well be enough to reduce the light level to allow the process to proceed.

Cheers, Robin
miketurner
Posts: 3
Joined: Sat Nov 14, 2020 3:46 pm

Re: Sensor Analysis

#3

Post by miketurner »

All worked well on the image camera, but the guide camera (ASI290mm Mini). I can't satisfy that camera for anything. Is there something special that needs to be done to it? One time "reduce lighting" then "increase lighting" The other camera was a breeze (ASI183MC).
Last edited by miketurner on Mon Jan 25, 2021 5:56 pm, edited 1 time in total.
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Re: Sensor Analysis

#4

Post by admin »

Hi Mike,

Glad to hear that that's sorted :-)

Cheers, Robin
Davidbr_48
Posts: 16
Joined: Mon Apr 19, 2021 11:17 pm

Re: Sensor Analysis

#5

Post by Davidbr_48 »

I am trying to run a sensor analysis, but am getting same results as Mike. I am using a ZWO 183 camera on a Celestron 8" edge. I've tried putting a white towel over the scope, and tried removing the camera from the scope and covering the sensor with a translucent eyepiece cover -- but same results.

I'm running the analysis in daylight, etc. How can I fix this?

thanks,

David Brooks / Seattle
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Re: Sensor Analysis

#6

Post by Davidbr_48 »

I neglected to mention - I'm working at F2 with a Starizona Hyperstar in daylight with tee shirt over scope. The sensor analysis keeps reverting to 234 ms and message to reduce brightness. No luck -- how to fix?

David / Seattle
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Re: Sensor Analysis

#7

Post by admin »

Hi David,

try covering part of the telescope aperture with a piece of card, or even pointing the telescope sideways rather than up (so it is not pointing at the bright sky). SharpCap is looking for a brightness level where the analysis can be run between exposure lengths of about 1ms and 1s as going either too short or too long can cause problems on some cameras.

cheers,

Robin
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