Zwo Asi224mc help

Can someone help me out with this camera in SGpro it’s a zwo asi224mc camera… when I image I get little squares all over my images? Gain 135 offset 20 and all so what should my ADU be for this camera in SGRo thanks again

Isn’t this the raw image prior to the debayering? These squares are in black and white and by debayering it, you will get a colour image.

Thank you for that! I’m still learning… how would I debayer it? And once I do that the squares will go away? Thanks again

As far as I understand it, it is done by the software used to stack and develop the photos. I have found that the debayer pattern for ZWO cameras is GRBG. There are many software options. If you go to the ZWO ASI website they will guide you to the most appropriate software to use. There are many who state that one brand is better than others but the most important thing to do is to get stuck in and climb up the learning curve.

Thank you for the info I will look that up now :slight_smile:

As for the ADU, I still struggle with that. When looking at the histogram of the flats, I choose an exposure that gives a peak between 30 -40 % although a few months ago I was trying to get the peak at 25%. I am not sure that I can tell the difference in the final image. As far as I understand it, the distribution of light in the flat should be linear. So if you have a 16 bit image the maximum value is 65k so I now aim for the ADU to be 24k. Hope that makes sense!

Thanks for that! I think I had mine at ADU 27500 for my flats I’m using a light panel flat box very diffuse to stop the black lines on the images

Also I’m wondering if I have to debrayer my flats, bias, and dark frames🤔

No, you do not debayer the calibration frames. Depending on the software you are using, debayering of the light frames may be done automatically, at the right stage in the process. Here are the processing steps in correct order:

  1. Create master bias
  2. Create master dark
  3. Create master flat
  4. Calibrate light frames
  5. Debayer calibrated light frames
  6. Register calibrated and debayered light frames
  7. Integrate registered light frames

FYI I have an ASI224MC that I purchased to use as a guide camera, and I have made a few DSO images with it. It’s really an amazing little camera. Due to very low dark current I have not found it necessary to use dark frames. And due to the small sensor, I have not found flat frames necessary either. So I skip steps 2 and 3 in the above procedure. Significant amp glow is the main complaint, but all things considered I am glad I bought it. It’s also an excellent camera for planetary “lucky imaging”.


Thank you very much Don for the info! How does it work as a guider compare to a orion Star shoot?

I haven’t used the SSAG - but I believe the ASI224MC would compare favorably.

The SSG is monochrome, so theoretically has better sensitivity. But in practice I have never found the ASI224MC to be deficient in sensitivity. I have only used it a few times as a guide camera, but everywhere I have pointed it I have found numerous potential guide stars.

And the ASI224MC has smaller pixels than the SSAG - 3.75 microns vs. 5.2 microns. The smaller pixels are an advantage for guiding and for planetary imaging.

I use a 60mm f/4 mini guide scope with it, after upgrading from an old Meade DSI-C camera on an 80mm f/11 guide scope. The difference is like night and day. I should have upgraded long ago.