QHYCCD

QHY 42 First evaluation

QHY 42 First evaluation
« on: November 02, 2018, 12:26:49 PM »
I got a QHY42 camera in april 2018, expecting interesting results in my field of interest : exoplanets transit computation.
I tried first to test the camera itself and measures its essential parameters, as literature is very weak for this camera.
This is the part 1, enclosed
Second part, is testing the camera "first lights", also enclosed.
I think many of you could be interested by this experience return !!
In summary, I do not regret having bought this camera with two remarks :
- software acquisition could be improved with several recurring bugs (not fatal, but annoying !)
- to get the best of the camera, it is necessary to change the approach concerning long pose acquisition : typically, changing 60 seconds poses by 30 times 2 seconds poses for instance.
Do not hesitate to contact me for further details !
Bruno
Officina Stellare RILA 400 F3.5 + ASA DM85 mount

Wandering Sand

Re: QHY 42 First evaluation
« Reply #1 on: November 12, 2018, 12:32:39 AM »
Dear Sir/Madam:

Thank you for your detailed test. We will study the question that you have propose.

Firstly, about the thermal noise, we will study the reason.
The thermal noise (3e) is large in the test data. According to the document the thermal noise should be 0.1e when the temperature is -15 ℃. So, we guess that the Thermal Electronic Cooler is out of touch with the cmos chip.

Secondly, about the full well charge, we will update a new FPGA version. It will support HDR output (Double channel 12bit output). By this way, dynamic range insufficiency can be solved.

Thirdly,about some improvement, we have drawn up a plan.
Single frame shooting delay problem: The reason is that the current single frame shooting is obtained from continuous video, this method will lead to the delay. In the new version we will add truly single frame shooting.
RBI problem: We will fix it. And did you use the latest version? Because the earliest did not set the Glow Inhibition Function open.

Best Regards!
zy

xs_man

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Re: QHY 42 First evaluation
« Reply #2 on: November 15, 2018, 12:58:55 PM »
Many thanks Bruno for this analysis of new QHY 42   :)

For short exposure deepsky imaging and VA observation, this camera
is a must have !

But the price is too high. I really hope that in the future Gpixel could find a
solution to decrease  greatly the price of their sensor. Only a dream ??

Please Bruno, could you show us 1, 2 and 5 seconds raw images  on a classical
target as M27 or M57 or M1 or M82 or M45 or  others ?
Is it possible to have raw images ?

Alb?ric

Re: QHY 42 First evaluation
« Reply #3 on: November 17, 2018, 09:30:08 AM »
@ZY : thank you for your answer : I am glad if my post can improve this superb camera
Thermal  noise : I think from your answer there is nothing to do on my camera
Same for full well charge : changing the FGPA is far out my competence !!!
For the software improvements, thank you very much : I will test along you implement them
True single frame shooting is a must
For RBI problem, I think I used the latest version but I well check

@xs_man : Yes the price of the QHY42 is quite high (9090 USD for a class 2 BSI cooled) but not so much compared to other camera (FLI 11002 or 16002) and the result is really impressive
I try to send you 1,2, 5 secs raw images of some well known targets as soon as the weather is clear (terrible for months in France right now !!)
Officina Stellare RILA 400 F3.5 + ASA DM85 mount

Re: QHY 42 First evaluation
« Reply #4 on: November 18, 2018, 08:39:48 AM »
@ZI For drivers, I use : QHY5IIISeriesDriver 80425 2018/04/26
and for ASCOM : QHYCCDASCOM-Captire-StarSenseSCI V0.1.51.18 2018/08/10
It seems the latest versions
I dont see any glow inhibition function (attached is the set up with ASCOM)

Officina Stellare RILA 400 F3.5 + ASA DM85 mount

xs_man

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Re: QHY 42 First evaluation
« Reply #5 on: November 19, 2018, 12:58:14 PM »
Quote
@xs_man : Yes the price of the QHY42 is quite high (9090 USD for a class 2 BSI cooled) but not so much compared to other camera (FLI 11002 or 16002) and the result is really impressive
I try to send you 1,2, 5 secs raw images of some well known targets 

Many thanks Bruno !
For me RAW images says more than any stacked image.
I hope that I will be possible to compare to the next QHY 2020.

Quote
as the weather is clear (terrible for months in France right now !!)

Oui, je vois de quoi vous voulez parler !  ;)

Alb?ric

Wandering Sand

Re: QHY 42 First evaluation
« Reply #6 on: November 19, 2018, 08:24:08 PM »
Hi,

You should use the SHARPCAP software.

Best Wishes!
zy

@ZI For drivers, I use : QHY5IIISeriesDriver 80425 2018/04/26
and for ASCOM : QHYCCDASCOM-Captire-StarSenseSCI V0.1.51.18 2018/08/10
It seems the latest versions
I dont see any glow inhibition function (attached is the set up with ASCOM)

Wandering Sand

Re: QHY 42 First evaluation
« Reply #7 on: November 20, 2018, 08:57:42 PM »
Hi,

Sorry for the last reply. The latest ASCOM version glow inhibition function is default open.

Best Wishes!
zy

Hi,

You should use the SHARPCAP software.

Best Wishes!
zy

@ZI For drivers, I use : QHY5IIISeriesDriver 80425 2018/04/26
and for ASCOM : QHYCCDASCOM-Captire-StarSenseSCI V0.1.51.18 2018/08/10
It seems the latest versions
I dont see any glow inhibition function (attached is the set up with ASCOM)

Wandering Sand

Re: QHY 42 First evaluation
« Reply #8 on: November 20, 2018, 09:05:13 PM »
Hi,

For the thermal noise, can you take some photos in some certain gain value and exposure time? And tell us your parameter. We will take some by using your parameter. Then we will compare yours and ours to judge the reason.

Best Wishes!
zy

Re: QHY 42 First evaluation
« Reply #9 on: November 21, 2018, 12:24:59 PM »
dear ZY,

I have redone thermal noise measures and I get :
at -10?C G=7 Offset=100 dark Noise = 3.4 e-/sec
at -10?C G=4 Offset=100 Dark Noise = 3.8 e-/sec

I will send you some photos (files are two large to be upload on the forum)

My main concern is not so much  the thermal noise, but with the acquisition software. As it is based upon a continuous image transfer, this has some (bad) consequences :
- it is not possible to get images exposure under 0.5 - 0.3 second. Under this number, the system freezes
- it is then impossible to get more than 4 or five bias frames
- the image taken at a given time is not the image which is shown and eventually store in a file. Then, the fits header data of the image are incorrect. The time for instance is wrong, as the filter name if the filter wheel changes at each image !

Besides, there are some annoying bugs :
- the setup camera setting procedure needs to be done each time when launching Maxim DL, and need to be redone in the camera control panel to be effective
- the setting procedure in the camera control panel can be done only once
- trying to disconnect the camera generates an error
- same if quitting the program (this is true for nay software : EZCAP-QT, SharpCap)

I understand that it may be not your priority but it would be nice to develop a good single shot software (Ascom based) ( and get rid of the annoying bugs) so that the QHY 42 owners could get the maximum value of this superb camera

thank you very much in advance
regards


Officina Stellare RILA 400 F3.5 + ASA DM85 mount

Officina Stellare RILA 400 F3.5 + ASA DM85 mount

Re: QHY 42 First evaluation
« Reply #11 on: November 21, 2018, 02:56:46 PM »
Officina Stellare RILA 400 F3.5 + ASA DM85 mount

xs_man

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Re: QHY 42 First evaluation
« Reply #12 on: November 22, 2018, 12:36:25 PM »
Many thanks Bruno !  ;)

The problem about read noise is annoying.
I really hope that it will be solved quickly because there is a gap between 1.7 e- and
3.4/3.8 e- ! A part of background may be lost.

To my opinion, what would be really interesting to compare this camera with a QHY 290 M.
The best Sony sensor for short exposure deep sky imaging.
Of course, main difficulty would be to compare equaly the 2 sensors. 

Many thanks.

Alberic

Re: QHY 42 First evaluation
« Reply #13 on: November 22, 2018, 01:08:30 PM »
It is not the read noise, but the thermal noise
For 2 seconds shots, it is completely neglectible
Officina Stellare RILA 400 F3.5 + ASA DM85 mount

Wandering Sand

Re: QHY 42 First evaluation
« Reply #14 on: November 22, 2018, 09:04:57 PM »
Dear Sir,

Thank you for your reply. We will handle this problem as soon as possible.

For your recommend , I will transfer to Mr.Qiu.

Thank you for your support!

Best Regards!
zy