ZWO ASI 224 MC with RC 8” focus

[Orion Carl]

Hi all, 

ive just bought a ZWO asi 224 mc for planetary imaging with my Orion RC 8” but I can’t get anywhere near focus.

i’ve had it as close as possible and very far away from the scope and I can’t seem to get as much as a donut on my screen. Been using the ASI 1600 with no problem and know roughly where it comes into focus.

i’ts a very small sensor on the 224 and I wondered if anyone had any experience with that camera on an RC?

Being a small chip would the starting point for focus be close or far out? Just trying to get myself a good starting point and go from there.

thanks in advance,

Carl

[sloz1664]

Hi Carl,

The distance from the front of the ASI 1600 to the CMOS sensor is 6.5mm and the ASI 224 distance is 12.5mm. You know the focus position of your scope with the ASI 1600. So all you need to do is focus the ASI 1600, swap the cameras and move the focuser in by 6mm. You should be somewhere near focus and be able to detect stars.

Steve

[Whistlin Bob]

Because of the small sensor I sometimes have this problem with the ASI224- it's because unless your object is perfectly centred you won't pick it up. One way to get round it is to turn the gain up to 600 and if it's de-focused you'll usually see a ghost of the image in the right direction.