I am somewhat a newbie when it comes to deep space imaging. I have a zwo asi294 color cooled camera and would like to get the most functionality out of it. I completed the sensor analysis for it and will be using the ‘smart histogram’ tool the next time out. I noticed under the camera settings there is a ‘Brightness’ and a ‘Gain/Exposure Shift’ settings. My Bortle Sky for my area is a 6.
Can someone give me a quick explanation between the 2 settings? Also, how would you calculate the ‘Gain/Offset’ setting.
Thanks in advance.
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Re: Deep Sky Imaging -
Hi,
brightness is the name the ZWO cameras use for 'Offset' (which is called 'Black Level') on some other brands of camera. All of them have the same effect - as you adjust them it changes a constant value that is the 'floor' level for pixel brightness values. Adjustment of this setting is required to ensure that the histogram for dark frames is clear of the left hand side of the histogram graph to avoid possible issues with 'black level clipping'. The smart histogram function will auto-set this for you, as it understands that brightness/black level/offset are all one and the same thing really.
Exposure/Gain shift is a convenience control that allows you to adjust the exposure up and the gain down (or vice versa) while keeping the same overall image brightness, but using a single control. It's handy to (for instance) reduce exposure and increase gain to compensate while focusing or framing the image, then go back to longer exposures/lower gain for actual captures.
cheers,
Robin
brightness is the name the ZWO cameras use for 'Offset' (which is called 'Black Level') on some other brands of camera. All of them have the same effect - as you adjust them it changes a constant value that is the 'floor' level for pixel brightness values. Adjustment of this setting is required to ensure that the histogram for dark frames is clear of the left hand side of the histogram graph to avoid possible issues with 'black level clipping'. The smart histogram function will auto-set this for you, as it understands that brightness/black level/offset are all one and the same thing really.
Exposure/Gain shift is a convenience control that allows you to adjust the exposure up and the gain down (or vice versa) while keeping the same overall image brightness, but using a single control. It's handy to (for instance) reduce exposure and increase gain to compensate while focusing or framing the image, then go back to longer exposures/lower gain for actual captures.
cheers,
Robin