QHY268C - Always buffers 3 frames

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admin
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Re: QHY268C - Always buffers 3 frames

#41

Post by admin »

Hi,

you could try using PHD2's testing mode - choose the 'Simulator' camera and 'On camera' guiding - you can then get PHD2 to pretend to guide (and dither) quite happily and have SharpCap talk to it for testing.

cheers,

Robin
AmargosaSky
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Re: QHY268C - Always buffers 3 frames

#42

Post by AmargosaSky »

Hello - I was wondering if anyone had any updates to this issue. For me, in SharpCap lastest versions of both 3.2 and 4.0beta), QHY268C still either buffers 3 frames, or sometimes unending buffer (requiring restart).

The best solution I heard from another user in this thread was in SC 3.2 to select a random exposure time, then set buffer to "on" then select actual exposure time, then set buffer to "off". This would result in no extra buffer frame after taking those steps. However, after the most recent QHY driver version, this no longer works and has returned to buffering 3 frames before displaying the first of those 3 frame (and always lagging 3 frames behind).

I tried to post in QHY forums, but the captcha says invalid site and doesn't let me post...

Thanks.
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Re: QHY268C - Always buffers 3 frames

#43

Post by admin »

Hi,

I thought the QHY forums had been removed, but it turns out they are currently here : https://bbs.qhyccd.com.cn/ They also have a support email (see https://www.qhyccd.com/contact-us/) and I think a ticketing system (but I can't find the link for that right now).

I'm afraid I have run out of ideas for this particular issue - if I had a camera to test with I might be able to find something out by trial-and-error, but even that isn't guaranteed. Without a camera to test with all I can do is follow the SDK documentaion :( I will note that I have had cameras with the same IMX571 sensor working from other manufacturers with no issues.

cheers,

Robin
mjindra09
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Re: QHY268C - Always buffers 3 frames

#44

Post by mjindra09 »

Hi
I have the same problem with the QHY 163M camera. Unlike QHY268C, in my case I lose "only" the first frame. I found that the ASCOM driver does not have this error. But in other hand, ASCOM driver cannot handle short exposures and is generally slower and less friendly.
Regards
Mirek
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Re: QHY268C - Always buffers 3 frames

#45

Post by admin »

Hi,

did you test the camera in still mode - either by unselecting the 'Live View' option on the left of the toolbar, or by setting the 'Force Still Mode' control to on - this is unsuitable for high frame rates, but should hopefully avoid the loss of frames when using longer exposures.

cheers,

Robin
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vichman
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Re: QHY268C - Always buffers 3 frames

#46

Post by vichman »

Hi Robin,

I also experience this problem quite regularly. This is quite painful, as whenever I change parameters of the camera then this behavior starts over again.
Each time I have to wait for several frames until I see an image. This is particularly annoying for longer exposures (e.g. having to wait for 60s just to see if setting the exposure time to 20s is OK)...
Switching to "still mode" seems to solve this issue, but there we have the problem with the different image size (different pixel width and height), which makes it impossible to combine frames taken in live mode with those taken in still mode...

Very weird.

CS
Stefan
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Re: QHY268C - Always buffers 3 frames

#47

Post by admin »

Hi Stefan,

I would strongly recommend going 'still mode all the time' - that is

* Set the 'Force Still Mode' setting to on , and save it in a default capture profile

If you do that then the camera will always run in still mode, regardless of whether the 'live view' option is selected in SharpCap. When in 'live mode', SharpCap simply repeatedly takes still frames. You will probably lose a bit of frame rate, but all the frames will be the same size.

The live mode/still mode size change is a pain, and I am stuck since I do not have the information needed from the SDK or from QHY to fix the problem.

* If I make still mode images the same size as live mode then you get a border of junk data around the edge - that messes up stacking in some programs
* If I make live mode images the same size as still mode ones then the pixels do not align unless I also know the offset needed in live mode to get alignment. If the pixels do not align then dark subtraction and flat correction will fail if for instance the dark was captured in still mode and the light frame in live mode. There is no way to work out the offset from the SDK :(

sorry for any inconvenience,

Robin
didiflei
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Re: QHY268C - Always buffers 3 frames

#48

Post by didiflei »

hello folks,

try the following:

connect the camera and then reload the profile.
This is only one click. It works perfectly for me.

didi
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TigerClaw35
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Re: QHY268C - Always buffers 3 frames

#49

Post by TigerClaw35 »

This workaround loading the profile only works with SharpCap 4.0 and not with SharpCap3.2. At the other side LiveStacking ist not working with SharpCap 4.0. In the newest version you can set LiveView off. But the frame problem still happens with 1-2 frames.

" The live mode/still mode size change is a pain, and I am stuck since I do not have the information needed from the SDK or from QHY to fix the problem."
I am also waiting for a fix since last year. I am completly disappointed. Unbelievable that some of us have to use the camera with workarounds. :(

Best regards
AmargosaSky
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Re: QHY268C - Always buffers 3 frames

#50

Post by AmargosaSky »

Update: The latest SC update improved the QHY buffering for me, when I pick the force still mode like Robin has suggested. (Doing so used to crash for me, now it's stable!). Works with QHY294M, still have to test with QHY268C...

JC
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