Hi / I recorded an occultation last night (SC 4.1.11786 as ADV bin2x2). The exposure was set to 50ms, i then changed that to 65ms. The Camera log file says 65ms. All well so far, but the adv is recorded with an interval of 0.188s !
At 00:31:00.169227 - The log file also says 639 frames captured at 5.3 fps. I have to say the screen update suggested 5 fps, but what can account for this anomaly ?
Also i have a problem with the filter wheel causing a fault when the profile is changed. I think the position is not saved or read correctly. Ive ignored this so far, as its not effected anything.
The log file and camera settings is attached.
Many thanks Robin !
Tim
(Abingdon)
QHY174mGPS wrong exposure interval.
QHY174mGPS wrong exposure interval.
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- 00_28_59Z_Clear.CameraSettings.txt
- Camera settings for occultation video
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admin
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Re: QHY174mGPS wrong exposure interval.
Hi Tim,
the camera settigns all look fine, but I did notice in the log that the QHY camera disconnected from USB at 21:32:49 and then reconnected a few seconds later. SharpCap can now handle this sort of event automatically - it will detect the disconnection and the reconnection and resume using the camera without any problems in about 90% of cases. Reconnection certainly worked this time - there is a log entry at 21:32:57 indicating that the reconnection was successful. I wouldn't expect the reconnection to affect the frame rate, but it might be possible.
I have another possible cause that I've worked out though. If I connect my 174GPS over a USB2 cable and use the same settings as you, I get a frame rate of about 5.4 frames per second. So, my guess is that you had accidentally connected the camera to a USB2 port (or, less likely, using a USB2 cable). It might be possible for a USB3 port to drop back to USB2 speed if the cable is damaged perhaps - I'm not sure about that.
For the filter wheel error, it looks like the saved profile has a bad value in it for the filter wheel position, so it is not being restored when the profile is loaded each time. If you re-save the profile it should fix the issue (if it doesn't let me know!)
Hope this helps,
Robin
the camera settigns all look fine, but I did notice in the log that the QHY camera disconnected from USB at 21:32:49 and then reconnected a few seconds later. SharpCap can now handle this sort of event automatically - it will detect the disconnection and the reconnection and resume using the camera without any problems in about 90% of cases. Reconnection certainly worked this time - there is a log entry at 21:32:57 indicating that the reconnection was successful. I wouldn't expect the reconnection to affect the frame rate, but it might be possible.
I have another possible cause that I've worked out though. If I connect my 174GPS over a USB2 cable and use the same settings as you, I get a frame rate of about 5.4 frames per second. So, my guess is that you had accidentally connected the camera to a USB2 port (or, less likely, using a USB2 cable). It might be possible for a USB3 port to drop back to USB2 speed if the cable is damaged perhaps - I'm not sure about that.
For the filter wheel error, it looks like the saved profile has a bad value in it for the filter wheel position, so it is not being restored when the profile is loaded each time. If you re-save the profile it should fix the issue (if it doesn't let me know!)
Hope this helps,
Robin
Re: QHY174mGPS wrong exposure interval.
Thanks very much Robin for the analysis. A poor USB connection is quite likely !
The connection is USB3 to a USB3 port on the laptop. The cable run doesnt normally create a problem, but i have the original 1.5m cable connected to an "active" (non-powered) 3m USB3 extension. However this is quite close to the maximum run. So yes, maybe the port was confused and re-set itself to USB2 !
USB disconnections have occurred before, but I usual take the plug out and re-connect it. I will keep a closer eye on this in future.
About the filer wheel - i will re-save all the profiles.
Tim
The connection is USB3 to a USB3 port on the laptop. The cable run doesnt normally create a problem, but i have the original 1.5m cable connected to an "active" (non-powered) 3m USB3 extension. However this is quite close to the maximum run. So yes, maybe the port was confused and re-set itself to USB2 !
USB disconnections have occurred before, but I usual take the plug out and re-connect it. I will keep a closer eye on this in future.
About the filer wheel - i will re-save all the profiles.
Tim
Re: QHY174mGPS wrong exposure interval.
Hi Robin,
A possible consequence, is that the exposure was 65ms, but with a delay between frames of 123ms. Is this possible?
Not that it effects the final occultation timing, only the SNR.
Tim
A possible consequence, is that the exposure was 65ms, but with a delay between frames of 123ms. Is this possible?
Not that it effects the final occultation timing, only the SNR.
Tim
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Re: QHY174mGPS wrong exposure interval.
Hi Tim,
in the case that transferring the frame over USB takes longer than capturing the frame, the camera has to wait idle between finishing one frame and starting the next to allow the data transfer to happen. This will, as you say, lead to a gap between the exposures given by
(1.0 / frame rate) - exposure time
cheers,
Robin
in the case that transferring the frame over USB takes longer than capturing the frame, the camera has to wait idle between finishing one frame and starting the next to allow the data transfer to happen. This will, as you say, lead to a gap between the exposures given by
(1.0 / frame rate) - exposure time
cheers,
Robin
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Jean-Francois
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Re: QHY174mGPS wrong exposure interval.
Hello Tim,
Or the USB Traffic value set too high ?
The ZWO Turbo has the opposite "value".
QHY = USB Traffic = 0 = very fast
ZWO = Turbo = very large = very fast
But you have USB Traffic = 0 in your CameraSettings.txt file
Sometimes I remark the following.
The exposure value is not taken if no "Return" is press or when the keyboard "|" is still in the exposure input field.
Regards,
Jean-Francois
Or the USB Traffic value set too high ?
The ZWO Turbo has the opposite "value".
QHY = USB Traffic = 0 = very fast
ZWO = Turbo = very large = very fast
But you have USB Traffic = 0 in your CameraSettings.txt file
Sometimes I remark the following.
The exposure value is not taken if no "Return" is press or when the keyboard "|" is still in the exposure input field.
Regards,
Jean-Francois
Re: QHY174mGPS wrong exposure interval.
Hi Jean-Francois,
You wrote: The exposure value is not taken if no "Return" is press or when the keyboard "|" is still in the exposure input field.
Yes, i have also encountered this. In one case it was set to 100ms, but i changed it to 80ms (or so I thought) but the exposure was 100ms. The camera settings confirmed that. So i am also careful to press return, or maybe to use the up-down nudge buttons.
Thanks for confirming this observation.
Regards, Tim
You wrote: The exposure value is not taken if no "Return" is press or when the keyboard "|" is still in the exposure input field.
Yes, i have also encountered this. In one case it was set to 100ms, but i changed it to 80ms (or so I thought) but the exposure was 100ms. The camera settings confirmed that. So i am also careful to press return, or maybe to use the up-down nudge buttons.
Thanks for confirming this observation.
Regards, Tim
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Re: QHY174mGPS wrong exposure interval.
Robin, to answer your question, yes. I have used USB TreeView and on at least one occasion have observed a bad USB3 cable show up as USB 2 connection. I highly recommend USB TreeView (freeware) to diagnose any and all USB connectivity issues. Yes I realize I failed to follow my own advice at first with my most recent USB problems, but when I did I was able to look deeper and discover my USB Drivers were newer but the wrong drive for my hardware. TreeView would have gotten me there much sooner... 