Gain for Uranus-c IMX585
Gain for Uranus-c IMX585
Hello everyone i have the P1 Uranus c and a celestron 127 SLT with a .5x reducer. I was simply wondering what would be the gain to be around with this camera for any dso? I understand im limited to under 30s exposures but i wonder what would be the best gain for 20-25s subs ?
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Re: Gain for Uranus-c IMX585
Hi,
not got experience of this camera personnaly, but fortunately PlayerOne have published the sensor data graphs on their web page (see https://player-one-astronomy.com/produc ... ra-imx585/).
If you look at the readout noise graph (about 3/4 of the way down the page - second graph down out of four), you can see that there is a big drop in readout noise going from gain 150 to gain 180 - this means that the camera switches from LCG to HCG mode somewhere in that range. For your setup I would suggest starting with gain 180 to take advantage of the low readout noise. Go to higher gain if you want, but probably not too much higher (300 max).
For more detailed suggestions, you can run SharpCap's sensor analysis and then the Smart Histogram functions to get a suggestion tailored for your camera and observing conditions
https://docs.sharpcap.co.uk/4.0/#!2!Sensor%20Analysis
https://docs.sharpcap.co.uk/4.0/#The%20 ... n%20Window
cheers,
Robin
not got experience of this camera personnaly, but fortunately PlayerOne have published the sensor data graphs on their web page (see https://player-one-astronomy.com/produc ... ra-imx585/).
If you look at the readout noise graph (about 3/4 of the way down the page - second graph down out of four), you can see that there is a big drop in readout noise going from gain 150 to gain 180 - this means that the camera switches from LCG to HCG mode somewhere in that range. For your setup I would suggest starting with gain 180 to take advantage of the low readout noise. Go to higher gain if you want, but probably not too much higher (300 max).
For more detailed suggestions, you can run SharpCap's sensor analysis and then the Smart Histogram functions to get a suggestion tailored for your camera and observing conditions
https://docs.sharpcap.co.uk/4.0/#!2!Sensor%20Analysis
https://docs.sharpcap.co.uk/4.0/#The%20 ... n%20Window
cheers,
Robin
Re: Gain for Uranus-c IMX585
I have the Uranus-C camera and had a discussion with Player One after first purchasing it. They confirmed that HCG is turned on at gain 180. Player One also said that ZWO switches on HCG at gain=150 and that Sony recommends that HCG be switched on at gain=250. This was back in June 2022 so I don't know if things have changed.
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Re: Gain for Uranus-c IMX585
Ah, interesting info 
So, if they are switching on HCG before the manufacturer recommended point, I would suggest the following additional test.
Set the camera to the gain you want to use (eg 180). Set a decently long exposure (ie 10s). Illuminate the sensor with bright light (either in a telescope or directly). With these settings, in RAW16 mode, check that the histogram is fully saturated (ie big peak at the far right at 100%, nothing else). If the histogram does not fully saturate even with further exposure increases and brighter illumination then increase the gain a bit and try again. Do *not* image at settings where the histogram does not fully saturate when overexposed.
cheers,
Robin
So, if they are switching on HCG before the manufacturer recommended point, I would suggest the following additional test.
Set the camera to the gain you want to use (eg 180). Set a decently long exposure (ie 10s). Illuminate the sensor with bright light (either in a telescope or directly). With these settings, in RAW16 mode, check that the histogram is fully saturated (ie big peak at the far right at 100%, nothing else). If the histogram does not fully saturate even with further exposure increases and brighter illumination then increase the gain a bit and try again. Do *not* image at settings where the histogram does not fully saturate when overexposed.
cheers,
Robin