I needed to drift align via (PHD->Indi) blind to the pole a week ago while on vacation with an astrotrac mount. I'm unable to use exposures less than about 7 seconds for the ASI120MM camera, less than that and I get the framing and exposure errors typically seen with this camera. I've updated the firmware to -compatible, high speed off, 8 bit. I'm on a Mac. While this will work for guiding it would be nice for drifting to be able to use a faster rate.

1). I assume my experience is normal with this POS camera?
2). Any recommendations on a better guide camera under indi; lodestar or sbig st-i ?

Thanks,
David

I have the ZWO ASI 120 MM USB3 and I don't have any issues with it. Do you have the USB2 version?

Yes, USB2 version

sorry, I can't help you there. The USB2 version is not recommended. I believe it is an issue with the controller board. I can tell you that my USB3 version works very well though.

Thanks, good to know.

Hi i had the same issue with my zwo asi120mc usb2. You need to reflash the firmware for it to run properly under linux. after doing this ive had no issues.

see: bbs.astronomy-imaging-camera.com/viewtopic.php?t=7354&p=15551

regards

Yep and as usual, only do this at your own risk. I cant give any guarantee that it will work for you.

Yes, I have done this too and have no issues with the ASI120mm - awesome camera. I do PA and guiding and drift and it works like a charm.

EDIT: I guide with PHD2 but I have tried internal guiding a couple of times and I can't recall any issues.

I'm under OSX on a Mac, I have re-flashed the firmware with the -compatible branch. I have a linux laptop with Indi, I'll see if its ok there maybe just an OSX issue.
Thanks
Daivd

I'd never considered the camera a POS, it's been a flawless performer for me as a guide cam since day 1, on Windows.

Last week I setup a Pi, oh what a nightmare - even the compatible firmware doesn't make it work right.

Turning off auto-bandwidth appears to make a significant improvement performance but not enough to justify continuing to use it when we get so few clear days in the UK - so its going to get replaced.

I think a QHY5-II mono has the same sensor/performance but without the bugs, would that be a fair assessment?

I don't know about the QHY5-II mono camera, but I have both the ASI120MC (USB2) and ASI120MC-S (USB3). Even after flashing the USB2 camera with the compatible firmware it didn't work for me on RPi3 or other Linux machines. The USB3 camera works like a charm though, also on OS X.

Thanks guys. I tried the camera under Ubuntu and although its much, much better, it still occasionally has the framing issue at a 1 second exposure. Seems fine at anything above that. Looks like it is unworkable under osx though. I'll look at getting the USB3 version.