QHY8 readout banding

[multiweb]

This is a bias frame at 0.001s taken with Maxim 5.16 - QHY8 - QHY8 ASCOM Driver StarSenseSci V2.0. Direct USB connection to the laptop running Win7 Home Premium 64bit - 8GB RAM. Normal Read - no binning. What's causing these lines? :shrug:

[mill]

These look like interference lines or clock signal lines.
Did you switch usb clamping on?
Try usb clamping on and off and also no usb during readout.

[originaltrilogy]

Also, have no network application running at same time. Browsers particular cause this.

[multiweb]

I doubt it is a USB line problem or network issue. The PC has plenty of RAM and grunt. No problem with the QHY9 in similar conditions.

Martin, I don't believe the StarSense setup gives me any options for clamping/USB readout like the QHY9 drivers do.

[Poita]

I had that banding on a quad-core i7 machine with 16GB of RAM... it turned out to be firefox running in the background. Have no idea why, but if I closed the other programs, the banding disappeared.

[multiweb]

Interesting. QiuHY just reported the same thing. Will try disabling all background processes and network see what happens. Thanks. :thumbsup:

[multiweb]

Well it doesn't seem to sort out the issue. I killed all background processes with EndItAll and disabled all networking. The QHY8 is the only thing running in Maxim. Still banding on both speeds.

[Marke]

Marc
I see same thing in QHY10 but not quite as obvious as this and there
was something in the user manual about it being ok and that
adding dark + bias removes it ?
I am using starsence as well and it aint lack of pc grunt thats for sure.
Mark

[Bassnut]

Is the QHY mounted to a scope or loose next to the laptop?.

[multiweb]

Well I guess it would reject with many subs and stacking but still.


On the table pointing down. It's not close to the laptop or anything else.

[peter_4059]

Marc,

I've never encountered this but have you tried a different/shorter/better shielding USB lead?

[multiweb]

The lead is direct to laptop, shielded with a ferrite block on top, 1.5m, dedicated USB port, no hub. Doesn't get any better than that. :shrug:

[peter_4059]

Sounds ideal but did you try a different lead?

[leinad]

Got another computer? try that , eliminate the laptop being the issue altogether.

[mill]

Even better hammer and chisel as last resort :)
Problems like this are just so hard to resolve or they just dissapear by them self.
Kick it?

[multiweb]

Yup. Done that. Same thing


Well I had to buy a new laptop because the QHY9 drivers wouldn't work with my older TOSHIBA WInXP pro 32bit. Now the old QHY8 is not working with the new 64bit drivers. Never can get it right with QHY driver I guess.. :rolleyes: The QHY9 ASCOM Drivers are the AstroSoftBe drivers and they work fine. The QHY8 ASCOM drivers are the home brew StarSensSci drivers and they obviously don't work that well.

[leinad]

Problem solved then :D Roll back the drivers or poke them to fix it :)

[mill]

How weird i had a old Toshiba with XP pro 32 bit and the QHY9 worked perfectly on that laptop.
Every time i upgraded a driver and it didn't work i just took one step back and waited for the next batch of drivers.

[peter_4059]

Can you use the QHY native Win 64/32 drivers instead of Ascom? These work fine for me.

[multiweb]

Well I'm all ears Peter. What do you have in mind? Using Nebulosity or EZcap? MAXIM DL will use ASCOM. I am not aware of any native drivers for the QHY8.

[Moon]

I have the same problem with a QHY9 / Maxim DL / ASCOM 64 bit drivers.
The only thing that sort of worked for me was to disable clamping.
James (biting my tongue)

[marki]

Yes you do not need clamping with the 64 bit drivers. I have only had one problem with banding using a QHY9 but that was user error. I had the Svideo cable plugged in the wrong way. The emc ring needs to be on the DC102 side not the camera side. Live and learn :)

Mark

[peter_4059]

Try ezcap or Nebulosity with the native win drivers and see if the banding goes away. This would then point to a problem with the driver (or Maxim).

http://qhyccd.com/download.html

[multiweb]

Well it works with the native driver in EZCAP 64bit. Driver is QHY8 64/32bit winUSB Driver (http://www.qhyccd.com/files/QHY8Drv64.zip). So this rules out any cabling issues and points towards a driver issue. Still to try with Nebulosity.

[multiweb]

No issue either with the native drivers in the latest Nebulosity 2. So far this tend to point to a driver issue (i.e QHY8 ASCOM StarSense Sci).

[peter_4059]

You could also try ascom driver in Nebulosity - if you get banding it is the driver. If you don't it is a Maxim issue.

[multiweb]

Hi Peter, did that already. :) That's why I said it's probably the QHY8 ASCOM StarSense Sci drivers. MAXIM DL is fine and can be ruled out because the banding will also occur using Nebulosity 2 and the QHY8 as an ASCOM camera but not with the native drivers.

(See attached)

[midnight]

This is indeed a very interesting thread Marc.

Looks as if you've narrowed it to the driver. I would not have thought of the driver being a potential source of problems so well done on finding this potential source of the problem.

I would never suspect the USB nor cable as there is error correction on the communication protocol. It's not like superimposing noise on an analogue line or whatever as it is entirely digital. Only speed would suffer due to interference I would think.

Darrin...

[multiweb]

That's what I've figured too. I've started a thread here (http://qhyccd.com/ccdbbs/index.php?PHPSESSID=d84796fc75dc589 3b381b71c9cfbeb69&topic=3194.0)on QHYCCD so hopefully some others will chime in and we can move toward a solution. The rig is kept to a minimum so we don't confuse the issue: QHY8 -> USB 2.0-> Laptop running Win7 64bit 8GB RAM. Network disabled. No other cameras plugged in or any other USB device plugged in. Camera capture software is the only thing running - all background processes are killed.