QHY268C live view very low frame rate?

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antialiasing
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Joined: Thu Sep 16, 2021 6:54 pm

QHY268C live view very low frame rate?

#1

Post by antialiasing »

Hi,
With the QHY268C I get ~0.5 fps in both SharpCap 3.2 and 4.0 (the latter installed with QHY's latest driver package). I attach a picture of sharpcap running with the camera. Changing parameters (USB traffic, DDR buffer, force still, etc) does not affect the low FPS. Have others observed the same behavior? I'm eager to try any ideas & fix this issue. Thank you,

Harry
Screenshot 2021-09-16 115246.jpg
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admin
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Re: QHY268C live view very low frame rate?

#2

Post by admin »

Hi,

a few things to try...

1) check you are connected via USB3 all the way from a USB3 port on your PC via a USB3 cable to the camera. This sort of frame rate would be expected if you were running on USB2.

2) Try changing the read mode option - I don't have this camera myself, but it may be that the photographic DSO mode reduces the camera frame rate in order to try to achieve improvements elsewhere (for instance reduced read noise)

3) Try turning up the USB traffic control a bit - although a setting of zero usually gives the fastest frame rate, sometimes it can try to push things a bit too far and you might find that a slightly higher value will give a better frame rate.

hope this helps,

Robin
antialiasing
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Joined: Thu Sep 16, 2021 6:54 pm

Re: QHY268C live view very low frame rate?

#3

Post by antialiasing »

Thanks for the reply. It ended up being a hardware problem: the USB 3.0 port (the single one on the CF-31) has the low FPS issue, but the CardBus USB3.0 card does not this this problem & shows about 7 fps. Also, plugging the camera into the USB port on the saddle of the mount (and then the mount is connect to the computer via one USB 3.0 cable--into the same USB 3.0 port on the CF-31 that shows low FPS when the camera is plugged in directly) does not have this problem. Pretty Weird!
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Re: QHY268C live view very low frame rate?

#4

Post by admin »

Hi,

ok, I've seen that once or twice before - a particular camera and a particular USB port just don't get on. Sometimes the camera fails to work, sometimes works badly. Adding a hub in between (I presume that's what wiring via the mount does) can fix the problem. I've noticed this most often with USB3 addin cards with Via or Renesas chipsets...

Anyway, glad you have a workaround.

cheers,

Robin
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