QHY Camera v 3 x older ASCOM options

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Stephen Petersen

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May 11, 2022, 10:49:26 PM5/11/22
to Open PHD Guiding
Greetings,

I have a QHY 5III-174M guide camera and I selected the QHY Camera as it is now an option. Upon start-up,  PHD2 behaves very erratically with the screen going overly bright and contrasty (is that a word?) and few stars being available when it starts looping exposures. More often than not, I have to keep restarting PHD2 to get a decent looking screen with enough stars to do an autoselect. I also now have to make sure I am in an area with lots of stars when doing a calibration or there will not be enough stars for PHD2 to select something. If I look at the area with SharpCap (I didn't pay attention to the gain setting but it was much higher than 40), there are lots of good stars but PHD2 just doesn't seem to be able to see them. Also, when doing calibration, the SNR is around 30 but when it is guiding, it is often over 300. Is this something to do with using the QHY camera option versus what I used to use which was QHYCCD-Cameras-Guider. Changing the gain setting doesn't seem to do anything especially with that contrasty look. More often than not, the ASCOM options are not available to be selected as it cannot see the camera.

So my questions are:

1. Does startup and calibration do something that is not done during normal guiding that affects the SNR and screen? 

2. Is the QHY Camera using some sort of QHY SDK instead of ASCOM?

3. What exactly is Camera gain in the Advanced Settings? PHD2 defaults to a setting of 40 with QHY Camera setting for the 174. If I hover over the setting, it says it defaults to 95% but what is 40 95% of? The doco says the PHD2 parameter is treated as a percentage of the range between the minimum and maximum gain values supported by the camera. Unity gain for that camera is around 170. ASCOM suggests a gain of 144 if I am using the QHYCCD-Cameras-Guider option. 

Any guidance would be most helpful. This happens all the time and makes start-up very frustrating especially when guiding is done through an OAG on a long focal length scope.

Regards

Stephen



Bruce Waddington

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May 12, 2022, 3:53:37 PM5/12/22
to Open PHD Guiding
Hi Stephen.  I don't think I'm following much of what you're saying.  I think you need to upload your PHD2 log files so we can tell what's going on with the camera:


The erratic behavior you're describing is probably because of the USB connection to the camera or problems with the driver.  I can't tell what driver you're trying to use but the logs will show us that.  In general, ASCOM drivers use the native drivers behind the scenes but the reverse isn't true.  PHD2's interaction with the camera is constant, it doesn't make any distinction between looping, calibrating, or guiding.  It seems to me like you've already answered the question on what the gain setting means - it's just a scalar value that tells the driver what value to choose within the supported range of minimum to maximum.  I doubt that your problems have much if anything to do with the gain setting, they're more likely to be associated with the hardware connection or the driver behavior.

Regards,
Bruce

mds....@gmail.com

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May 13, 2022, 5:06:06 PM5/13/22
to open-phd...@googlegroups.com

Hi Bruce,

 

Thanks for the response. I cannot access the logs right now, but I will pass them on as soon as I can.

 

I believe my camera is using the qhyccd.dll (question two in my original posting) which I assume is what is used with the QHY Camera option in the QHY cameras available as a guide camera. I have some issues with that camera in older versions of the qhyccd.dll as it is very finicky with USB connections (I have changed USB cables many times with no discernible difference). The latest (beta version?) of the drivers seems to fix all the problems I have with that camera.

 

So, it is possible for me to replace the qhyccd.dll driver in the PHD2 directory with the latest version? SharpCap uses the latest driver as I can install it in SharpCap with the QHY driver installation process.

 

The 174M an outstanding camera but it’s so damn frustrating to use. I have to make sure my main imaging camera is not on when I connect to the 174M as it won’t appear in the list of cameras. Once I can see it, I can turn on my imaging camera. I connect to all my cameras from a NUC sitting at the base of my EQ8-R which uses the on-board cable management system. I have directly connected the camera to the NUC but it makes no difference with how it behaves (using different USB cables as a test), thus ruling out any USB issues with the system.

 

As far as gain goes, what is that 40 number that it defaults to? Is it 40% of the available range of gain or is it 40 as a gain setting for the camera? 40% of the available range probably relates to what the ASCOM offering thinks is appropriate which in reality would be a gain of around 144.

 

FWIW, I had exactly the same issue with a ZWO ASO 290 MM Mini with the initial start-up being almost devoid of stars and the screen being very overly contrasty. It always lost stars and reported star mass issues but in SharpCap, it worked like a charm.

 

Regards

 

Stephen

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