Horezontal lines across the image

[neilgwilt]

Hi
Hope someone can advise please. I'm using windows 11 and an celestron Evo 6" telescope. The camera is an Altair Hypercam 183C ( brought about 2007). Recently I have seen that the final image has a number of Black lines runing parallel across the image from left to right. The Camera is using USB2, can use usb3 but Sharpcap reverts to 2 when I change anything. Exposures of about 6-10 seconds and mid 800 gain. Target Orion Nebula. This was not an issue on windows 10. Dark flats applied, and recording as Fits images
Can anyone advise a likely cause please
Many thanks
Neil`4

[admin]

Hi Neil,

sort of faint grey lines - some brighter, some darker, more visible if you stretch the image?

Capture.JPG (136.58 KiB) Viewed 8220 times

That's normal(ish) for CMOS cameras - my suspicion is that they come from fluctuations in the power supply voltage (USB) when the image is being read from the sensor, but I have never managed to prove it properly. If it is the power supply then different PCs may have better/worse USB voltage regulation and therefore may give different results. You can also try different gains or different USB speed settings to see if those help. Finally, SharpCap has a digitial processing tool called 'banding suppression' that helps get rid of these lines if you can't get rid of them any other way - see https://docs.sharpcap.co.uk/4.0/#!2!Pre-processing

cheers,

Robin