Gain / Exposure Shift Slider Missing

[AngeloM]

I'm imaging the moon with Sharpcap 4.1.13621, 64bit and the ZWO ASI678MM and the slider that shifts Gain and Exposure settings is missing. It was there yesterday and I haven't upgraded my software. Was this feature removed or has it been hidden from the controls via a keyboard shortcut? Being able to raise Gain While Lowering Exposure and/or visa versa was really helpful.

Michael

[AngeloM]

Never Mind. It just reappeared. Please Delete this post.

[admin]

Hi,

I think I will keep this post, as the control doesn't always show, and it's good to explain why...

Possibly you accessed your camera via the ASCOM driver or the DirectShow (webcam) driver option by mistake - both of those would cause the Exposure/Gain shift not to show up.

Basically, the Exposure/Gain shift control only appears if SharpCap understands how the gain control affects the brightness of the image. This is known for *most* astro cameras, but for ASCOM and DirectShow cameras, the gain values are just numbers - there is no agreed definition of how those numbers correspond to changes in image brightness. Additionally, for many (but not all) QHY models, the gain values are uncalibrated so that the exposure/gain shift may not show by default.

If you use an ASCOM camera or a QHY camera and SharpCap has sensor analysis data for the camera then that provides a calibration allowing the exposure/gain shift to show. SharpCap has built in data for many cameras, if your camera doesn't have data then you should be able to perform a sensor analysis to measure the data needed, then the control should show up in the future (after camera close/reopen). Remember that you would need to run the analysis for each camera colour space (ie RAW8, RAW16) that you intend to use.

cheers,

Robin

[AngeloM]

Thank you Robin.
I've worked with computers for over 40 years now and have seen things appear and mysteriously disappear for no apparent reason. I appreciate you explaining what to check next time.

Michael