Hi.
Could someone explain how the 'Gain Value' in sensor analysis corelates to the 'Gain' slider please.
In sensor analysis the Gain Value column goes from 0 to 100, or 0 to 200 depending on the mode, but the Gain slider goes from 0 to 339 in all modes, so it's a bit confusing.
Thanks
Mike
QHY268C Gain values
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Re: QHY268C Gain values
Hi,
the 'gain value' is the value of the gain slider. However... SharpCap may not analyze the full range of the gain slider.
Some cameras have a very wide gain range - I have one on my desk at the moment that has a range in excess of 3000:1. SharpCap typically does not take the analysis beyond 300 times as bright as minimum gain for two reasons
1: Beyond 300x gain, cameras tend to be so noisy as to be unusable for any deep sky work. Beyond 1000x gain they are typically too noisy for pretty much anything.
2: Analyzing a very wide gain range requires an equally wide range of exposure times, which would either require rather long exposures (>1s) leading to slow analysis or very short exposures (<1ms) which have their own issues with fine adjustment not being available on some cameras.
Essentially, near the beginning, the analysis works out how large a gain value it can go up to and still keep the analysis within reasonable bounds of exposure length. Depending on the model/mode, this might be 100, 150, 200 gain.
cheers,
Robin
the 'gain value' is the value of the gain slider. However... SharpCap may not analyze the full range of the gain slider.
Some cameras have a very wide gain range - I have one on my desk at the moment that has a range in excess of 3000:1. SharpCap typically does not take the analysis beyond 300 times as bright as minimum gain for two reasons
1: Beyond 300x gain, cameras tend to be so noisy as to be unusable for any deep sky work. Beyond 1000x gain they are typically too noisy for pretty much anything.
2: Analyzing a very wide gain range requires an equally wide range of exposure times, which would either require rather long exposures (>1s) leading to slow analysis or very short exposures (<1ms) which have their own issues with fine adjustment not being available on some cameras.
Essentially, near the beginning, the analysis works out how large a gain value it can go up to and still keep the analysis within reasonable bounds of exposure length. Depending on the model/mode, this might be 100, 150, 200 gain.
cheers,
Robin
Re: QHY268C Gain values
Thanks Robin, understood.
Mike
Mike