Vertical banding with the zwo 120mm...a simple solution

thidor05

since the AS120 version was introduced, a number of users reported vertical banding in processed imaged, especially when using high gains.

the problem was typically addressed by applying darks to the images. This solution however does not always work since the banding pattern changes each time the camera is reset, or a change in the gain settings is applied.

Another, more efficient solution it to wobble the planet within the FOV during image acquisition.

This can be done using the mounts hand paddle for instance.

No darks required. It takes car of all the vertical lines after the stacking is done. Voila!

Doris Thibeault

riklaunim

In planetary imaging it's not a problem as there are thousands of frames usually and the image isn't stretched in processing. Fixed pattern noise (vertical banding) is a problem in DS astrophotography where there is much less frames frames and the image is stretched a lot. Dark frames does remove FPN (and amp glow) in such cases. This noise is fixed unless the camera or sensor try to limit FPN by digital means (miniCAM5 does that and it dark frames aren't reusable). What's not removable by dark frames is random horizontal noise - that can be removed by processing. Autostakkert2 has an option to remove them as well as help with vertical FPN if dark frame/bias have problems.

But still doing like CH4 or UV imaging with ASI120MM will be somewhat affected by FPN as on high gain and needed longer exposures the noise is quite apparent.