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Forunke

Guiding cam randomly flips / mixes image

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Posted (edited)

Ok, so this is a really annoying bug / problem that I have with my setup:

From time to time, in non regular intervals the image my guiding cam (ZWO ASI120) send seems to get flipped / mirrored or looks like it's from a completely different patch of sky.

When I'm paying attention to the guide images I can clearly see that the image seems to be flipped in some way.

It only happens for 1 frame PHD send a warning ( No star found / Star lost Mass changed) and after that everything is fine again. My gear is all connected to a single USB3 Hub which then runs via powered USB3 cable to my Pc.

I'm not binning and have the noise reduction off (though PHD might got hickups while processing) but it still happens. Sometimes there are minutes between two events sometimes it happens 5 times in a row.

It also seems like it's only happening during guiding, I haven't seen it happen during calibration yet...

 

I'm completely clueless what's happening or how to get rid of it, any help / idea is greatly appreciated.

Edited by Forunke

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I had the same flipping problem, after trying everything I could think of I stopped using it. Nothing I tried worked. 

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1 minute ago, Anthonyexmouth said:

I had the same flipping problem, after trying everything I could think of I stopped using it. Nothing I tried worked. 

So how did you go about guiding then? Another cam? Different software?

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My ZWO ASI 120MM occasionally has "Split Frames" when I use it in SharpCap to take 30 second exposure sequences (frame is split vertically with left and right halves swapped)

Typically starts okay, then after a while I get a series of Split frames, then it corrects.

Never had it in PHD2, I'm not using the ASCOM driver.

Michael

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44 minutes ago, Forunke said:

So how did you go about guiding then? Another cam? Different software?

New camera, well my asi290mc camera I usually use for planetary imaging. Spoken to a couple of others here who had the same problem. No solution found as far as I know. 

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Just now, Anthonyexmouth said:

New camera, well my asi290mc camera I usually use for planetary imaging. Spoken to a couple of others here who had the same problem. No solution found as far as I know. 

Well I was thinking about getting a new guidescope... maybe I should just go for a bundle then and use the ASI120 for planetary

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Out of interest, is this the USB3 model (of the ASI120), or the old USB2 one?

James

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7 hours ago, michael8554 said:

My ZWO ASI 120MM occasionally has "Split Frames" 

Yes, I’ve had that too, although in my case it does sometimes happen in PHD2.  This is for an old USB2 ASI120. 

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9 hours ago, JamesF said:

Out of interest, is this the USB3 model (of the ASI120), or the old USB2 one?

James

The old usb2 one for me. Was having guiding issues from lost stars for ages and only by chance was looking at the screen when I saw it flip then flip back. During that time it lost the star. 

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There is a firmware "upgrade" for the USB2 models.  I found that made the camera a bit more stable at the expense of dropping the maximum frame rate slightly.  Might be worth a try?

(Actually the alternative firmware is, if I recall correctly, to return the camera to work in compliance with the USB2 specification because the default firmware bent the rules a bit , I assume to try to increase the frame rate as far as possible.)

James

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20 minutes ago, JamesF said:

There is a firmware "upgrade" for the USB2 models.  I found that made the camera a bit more stable at the expense of dropping the maximum frame rate slightly.  Might be worth a try?

(Actually the alternative firmware is, if I recall correctly, to return the camera to work in compliance with the USB2 specification because the default firmware bent the rules a bit , I assume to try to increase the frame rate as far as possible.)

James

I'll double check mine but pretty sure I'm on the latest firmware. Sure that was one of the things I went through. Only ever use it with phd2 and brief spells with sharp cap for polar aligning. Never in sharp cap long enough to notice any issues there. 

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Are you running this through a usb/usb3 hub. I found mine did this but was definitely better when running it off its own dedicated usb lead to usb2 port.

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Coming back to post some results from playing around with some settings.

I managed to stop the image flipping by using Subframes (PHD2, settings, camera, use subframes), which makes me think there's a bottleneck somewhere down my USB3 line.

Will have to try the suggested firmware update to see if it helps but ultimately I'll probably switch to ethernet for data transfer.

 

Thanks for all suggestions!

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6 hours ago, Forunke said:

Coming back to post some results from playing around with some settings.

I managed to stop the image flipping by using Subframes (PHD2, settings, camera, use subframes), which makes me think there's a bottleneck somewhere down my USB3 line.

Will have to try the suggested firmware update to see if it helps but ultimately I'll probably switch to ethernet for data transfer.

 

Thanks for all suggestions!

converting to use cat5/6 ethernet wont help, any usb-cat5/6 converters will be slower than usb3. 

I did try a dedicated usb cable but still had the same issue. 

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