ASI178MC-Cool Artifact

mirx9

Hi everyone,

I just received an ASI178MC-Cool and I am getting some artifacts, where the left half of the image is brighter with certain settings. Below is an example of what I'm seeing.

BandingCapture.JPG

After some testing, I'm noticing that it appears with the following settings:

• 16 Bit unchecked, USB Traffic >51

• ROI defined and switch between 16 bit checked and unchecked

• Binned vs not-binned follows the same "rules" as above, but binning makes the artifact more obvious which is why the attached image is binned.

If I go to 16 bit mode in FireCapture, I don't see the issue, unless I have an ROI defined and then switch between 16 bit and 8 bit mode. In 8 bit mode, if USB Traffic is 51 or less, no artifact, but at 52 and above, it appears.

The artifact is always centered in the image, and even if I define an off-center ROI, once I switch between 16 bit and 8 bit modes, the artifact appears again in the middle of the ROI part of the image. Very strange, any ideas what is going on?

Laptop is late-model i7, 16GB RAM, SSD, Windows 8.1, USB3.0 I mainly use FireCapture v2.5.02 Beta, but I also installed SharpCap just to confirm that the artifact appeared there also, and it did. I also have an ASI120MM which does not show this issue. Is this reproducible with other ASI178 cameras?

Oh, one other test I just tried: when plugged into a USB2.0 port, I don't get the artifact under any settings, but the frame rate is ~6 fps for 8 bit full frame.

Thanks,

Matthew

rkayakr

I have seen the same issue in my ASI178MC (not cooled). It is a PITA to eliminate in post processing. Here is an example of 100 6s images captured in Firecapture stacked. ROI was 1240x1024, gain 350. This was on an unguided C8 (2000 mm FL) so you can see some drift. Attached is the stacked image simply stretched and a final copy after processing.

mirx9

Sorry to hear you're struggling with this too, but you managed to get a nice image nonetheless.

Could you try the things I mentioned above to see if you have a similar "trigger" for this behavior?

Specifically:

1) If USB Traffic is 51 or less in 8 bit mode, do you still see the artifact when in full sensor mode (no ROI)

3) Do you see the artifact in 16 bit mode when in full sensor mode?

2) Set an ROI but don't change from 16 bit to 8 bit or vice-versa. If you already see the artifact, try going back to full sensor until you don't see the artifact, then go back to ROI without switching bit depth.

I'm curious to see if the same factors apply to your camera.

Thanks,

Matthew

rkayakr

Matt

I'd like to, but it's 10F and cloudy here for the next decade. Present long range forecast through end of January say no chance.

Will try when weather permits.

Bob

Sam@ZWO

We found this bug and will fix in our next release version

please change the USBTraffic below 50 to fix this problem temporarily

this problem only exist when you use 8bit output and didnot select high speed output

this is because the USB traffic value we set too high

Sam@ZWO

we already released a new SDK fixed this problem

SharpCap already updated

https://drive.google.com/uc?export=download&id=0B7cWKVXZzvOEdkMxVGdsV2MtOGM

FC will update soon

mirx9

Sam,

Thanks for tracking down and resolving this problem. Looking forward to the next release of FC.

I'm still waiting for first light with the ASI178 due to weather. :(