Black Band

[Heyes56]

New to forum help needed. I have had this problem a couple of times now over the last few weeks. I hope someone can help.

I am seeing a black band at the bottom of some of my imaged. They are all 10min light frames. At first I thought it was my filter wheel out of position but it seems to be on every other image. I used the same setup the night before with no issues.

I'm using a Explorer scienific Apochromatic 102.    ZWO Optical ASI 120mm-S (CMOS). ZWO Electronic Filter Wheel 1.25inch with R,G,B filters and ASIAIR 

Any ideas would be helpfull.

[JonCarleton]

A pure guess, but since it is clobbering the bottom bit of your image, it smacks of not enough time to write the whole image (most software writes images from top to bottom).  Or asking the camera to do something else before it finishes writing.

For a DSLR, this might be due to a very slow or defective SD card combined with large images and/or short time between images.  For USB cameras, perhaps a USB3 camera into a USB2 port or something busy going on with the host computer.  If you are using a Raspberry Pi, it could be the microSD chip used for the drive is too slow.

If you reduce the image size significantly and the problem goes away, then one of the above is probably in play.  Otherwise, look for something mechanical.