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QHY2Pro timing issue

QHY2Pro timing issue
« on: January 29, 2008, 04:56:25 PM »
I've made a "time-exposure" test.

Camera shoots in moderately dark room, without any optics attached.

See picture,
1-st column is exposure time in milliseconds.
2-nd column = average picture value (L).
3-rd column = L - bias value (measured with cover closed).

Plot trend shows, that I have 330ms addition to every exposure value.
I.e. when I think I do 10ms shot, I get 340ms real exposure.

It's not a big problem for long exposures, but it makes impossible to shoot in bright conditions.
As a result, can't make "flats" in daylight.

PS.
I use QHY drivers and QHY2Pro SDK (to automate shooting and measuring).
But the same problem I see with MaximDL plugin, so I think the problem is in drivers or firmware.

Can it be fixed somehow?
« Last Edit: January 29, 2008, 04:58:04 PM by Ivan7(rus) »

Re: QHY2Pro timing issue
« Reply #1 on: January 29, 2008, 08:32:23 PM »
Nice work! I hope it can be fixed.

  Sander
All the best,

  Sander

Takahashi EM-400 - Edge HD 1100 - HyperStar 3 - WO M110 - FR-III/TRF 2008
QHY-8, DSI, QHY 5L-IIc, IMG0H mono, PC164 video
PixInsight, Nebulosity, DeepSkyStacker, PaintShopPro X2, PHD, FireCapture, Autostakkert

QiuHY

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Re: QHY2Pro timing issue
« Reply #2 on: January 30, 2008, 11:21:50 PM »
Hello,

            Do you test the astrowin ?  I think it should be the problem of my DLL.I will check it soon.

Best regards,
Qiu Hongyun

Re: QHY2Pro timing issue
« Reply #3 on: January 31, 2008, 05:01:12 PM »
Hello,

            Do you test the astrowin ?  I think it should be the problem of my DLL.I will check it soon.

Best regards,

Hi, Qui!

From 1-st look, astrowin can make very short exposures, but I see there another problem.

Exposures 1..29ms make very dark picture,
but exposure=30ms makes partly overexposed image. From my calculation, real exposure is 30ms+330ms, just like when I use SDK.

See 2 screenshots attached.
« Last Edit: January 31, 2008, 05:07:01 PM by Ivan7(rus) »