Black Bar Across Image (ML16200)


Tony Benjamin <tonybenjamin@...>
 

I've noticed that I am getting a "Black Bar" across some of my images (at regular intervals) and was wondering what might cause that? Here are its characteristics:

  • Occurs on the very 1st image each night;
  • Occurs on every 13th image thereafter; and
  • Occurs in both 2Mhz and 12Mhz download speeds.
I'm using the same driver I always have (Harmuts), which has never given me any problems. The only real change is that I recently got the camera back from FLI.

Any ideas?


Ben Koltenbah
 

Tony:

Does the location or size of this bar change each time?  What acquisition software are you using?

Is there a change of download mode occurring in your sequence before each of these frames such as for auto focus or some other periodic step?  I ask because one thing that could cause this is mode change and the buffer is not cleared before the next frame.  You end up with a mix of data from different modes.  You can see this happen with FLIGrab.  In fact, I suggest you take some frames with FLIGrab to see if the problem occurs there as well.  I can't recall now whether or not Hartmut's driver has some step to mitigate this.

If you haven't done so already, be sure to check with a different USB cable and if possible another computer just to eliminate these as sources of the problem.

Ben


Steve Reilly
 

Had that issue before and turned out to be the USB port or cable. Seems I narrowed it down to the port. Changed to an inside computer to test and no issues using same cable.

 

-Steve

 

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of Tony Benjamin
Sent: Sunday, March 15, 2020 11:16 AM
To: main@ap-gto.groups.io
Subject: [ap-gto] Black Bar Across Image (ML16200)

 

I've noticed that I am getting a "Black Bar" across some of my images (at regular intervals) and was wondering what might cause that? Here are its characteristics:

  • Occurs on the very 1st image each night;
  • Occurs on every 13th image thereafter; and
  • Occurs in both 2Mhz and 12Mhz download speeds.

I'm using the same driver I always have (Harmuts), which has never given me any problems. The only real change is that I recently got the camera back from FLI.

Any ideas?


Tony Benjamin <tonybenjamin@...>
 

Hi Ben,

No, the area remains exactly the same. I've used Voyager/SGP and also tried it in FLI Grab. The bar shows up in all of them. Heres a quick video - https://www.youtube.com/watch?v=StDDz82ud1I&feature=youtu.be

Good point on the mode change because I was doing 2 min exposures with a focus run every 30 min...which works out fairly close to this bar occuring around each focus run...which changes from 2MHz to 12MHz.

I did try a different cable as well as connecting direct to the computer, as opposed to going through a hub. Didn't help.

I looked at Harmuts driver properties and I don't have any pre-flush settings set...maybe I need to change those?



Dale Ghent
 

You can also try it in NINA’s native FLI driver. I have it so that if the driver has issues grabbing a row and the FLI SDK throws an error, that will be logged. If no error is thrown when the affected row is fetched then the issue is in the data and the FLI SDK is not aware of whatever the deeper problem is. 

On Mar 15, 2020, at 12:06, Tony Benjamin <tonybenjamin@...> wrote:

Hi Ben,

No, the area remains exactly the same. I've used Voyager/SGP and also tried it in FLI Grab. The bar shows up in all of them. Heres a quick video - https://www.youtube.com/watch?v=StDDz82ud1I&feature=youtu.be

Good point on the mode change because I was doing 2 min exposures with a focus run every 30 min...which works out fairly close to this bar occuring around each focus run...which changes from 2MHz to 12MHz.

I did try a different cable as well as connecting direct to the computer, as opposed to going through a hub. Didn't help.

I looked at Harmuts driver properties and I don't have any pre-flush settings set...maybe I need to change those?

<FLI_ML16200.JPG>


Willie Strickland
 

Is there any processing involved, ie. auto-dark?  If so, is the master from before or after the trip to FLI?

Willie


Ben Koltenbah
 

OK, Tony, thanks.

Another thing I recommend is trying it out with SGP's updated native FLI driver, however from what you've described you will probably see the same behavior.  I've been advising the SGP developers on updating their driver, and I've "qualified" it to my satisfaction, but I recommend others do their own checks as well since it's new.  If this is due to the buffer issue following a mode change, I do know that SGP is taking steps to do a read (flush) following mode changes.

As for RBI mitigation, I don't think that's going to help you here.  If you've ruled out cabling, USB, port, driver, software at this point, you may have an electronics issue and will need to contact FLI about it.

Ben


Bill Long
 

Does this happen only with a particular frame type (i.e. Light, Bias, Flat, Dark...)? 


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Tony Benjamin <tonybenjamin@...>
Sent: Sunday, March 15, 2020 9:06 AM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Black Bar Across Image (ML16200)
 
Hi Ben,

No, the area remains exactly the same. I've used Voyager/SGP and also tried it in FLI Grab. The bar shows up in all of them. Heres a quick video - https://www.youtube.com/watch?v=StDDz82ud1I&feature=youtu.be

Good point on the mode change because I was doing 2 min exposures with a focus run every 30 min...which works out fairly close to this bar occuring around each focus run...which changes from 2MHz to 12MHz.

I did try a different cable as well as connecting direct to the computer, as opposed to going through a hub. Didn't help.

I looked at Harmuts driver properties and I don't have any pre-flush settings set...maybe I need to change those?



Tony Benjamin <tonybenjamin@...>
 

So far, I have only seen it with Light Frames. I ran a fresh set of Bias/Darks and no sign of the black bar. 


Bill Long
 

Okay. That is odd. How is the camera being powered?


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Tony Benjamin <tonybenjamin@...>
Sent: Sunday, March 15, 2020 3:52 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Black Bar Across Image (ML16200)
 
So far, I have only seen it with Light Frames. I ran a fresh set of Bias/Darks and no sign of the black bar. 


Tony Benjamin <tonybenjamin@...>
 

The camera is being powered directly from the supplied power brick. I did check that voltage and it is a steady 13.4 DC Volts.


A J Trotta
 


------ Original Message ------

From: Bill Long
To: main@ap-gto.groups.io
Sent: March 15, 2020 at 6:06 PM
Subject: Re: [ap-gto] Black Bar Across Image (ML16200)
Okay. That is odd. How is the camera being powered?


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Tony Benjamin <tonybenjamin@...>
Sent: Sunday, March 15, 2020 3:52 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Black Bar Across Image (ML16200)
 
So far, I have only seen it with Light Frames. I ran a fresh set of Bias/Darks and no sign of the black bar. 


A J Trotta
 

I am late to this discussion so I apologize if this has already been suggested. I have an Sbig 8300 stf . I had the same problem with light frames . Sbig suggested I delete the driver and re install .  Problem solved and has not recurred.

Sent from XFINITY Connect Mobile App



------ Original Message ------

From: Bill Long
To: main@ap-gto.groups.io
Sent: March 15, 2020 at 6:06 PM
Subject: Re: [ap-gto] Black Bar Across Image (ML16200)

Okay. That is odd. How is the camera being powered?


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Tony Benjamin <tonybenjamin@...>
Sent: Sunday, March 15, 2020 3:52 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Black Bar Across Image (ML16200)
 
So far, I have only seen it with Light Frames. I ran a fresh set of Bias/Darks and no sign of the black bar. 


Tony Benjamin <tonybenjamin@...>
 

Hi AJ,

Thanks, I'll give that a go :)

Tony