QHYCCD

Looking for bias, dark, flat of qhy9

Looking for bias, dark, flat of qhy9
« on: June 04, 2009, 04:00:16 AM »
Hello,
I am seriously looking on the qhy9.
But before buying it, i would like to check the way it works. For this, i am looking for 2 bias, 2 darks and 2 flatfield pictures to analyze them.
Can anybody help me ?
Thank you.

Re: Looking for bias, dark, flat of qhy9
« Reply #1 on: June 07, 2009, 05:03:54 AM »
I might be able to help out.  Are cropped fits OK?

BTW..if your looking at "characterising" the camera's performance I can help with that as I have already done some work there.

Terry

Re: Looking for bias, dark, flat of qhy9
« Reply #2 on: June 08, 2009, 08:20:06 AM »
Hello,

Yes i want to try to characterise the camera performance. For this i need full fits image and the temperature.
I want to try to check the read noise, the dark current and the linearity.

But if you have already done this work, looking at your results woulb be great for me.

Re: Looking for bias, dark, flat of qhy9
« Reply #3 on: June 08, 2009, 10:51:31 PM »
I need to get some more flat data to confirm my value for system Gain (which is markedly different for the 0.4 e-/ADU given elsewhere on this forum):

At -10 C and normal download speed:
Gain (For Gain=0 setting) = 0.61 e-/ADU
Read Noise (For Gain=0 setting) = 12 e- RMS
Dark Noise = tba

Dark noise appears very low and will get some data shortly.

Most importantly sensitivity does not dissappoint.  Much higher than the Canon DSLR I used the QHY9 to replace.

Terry

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Re: Looking for bias, dark, flat of qhy9
« Reply #4 on: June 08, 2009, 11:38:47 PM »
Hello,

        The system gain is not the same for each camera. We just test another camera here is some reuslt:


System =0.49
Dark image STD=20.3

Readout noise=10e.

         I think there is a spread of the system gain and sensor readout noise. So the final readout noise is also
a spread.

        In gain=0, if the system gain =0.61, the full well will not match the ADC full range. So you need to increase
the gain and make it match . Because in high gain the readout noise will reduce .   


Best regards,
         
Qiu Hongyun

Re: Looking for bias, dark, flat of qhy9
« Reply #5 on: June 14, 2009, 04:25:48 PM »
Here are my values for the QHY9

CameraQHY9
OwnerTerry Lovejoy
SensorKodak KAF-8300
Resolution[/td[td]3336 x 2496 (output from ASCOM)
3362 x 2538 (actual active pixels)*
Pixel Size5.4 micron
Sensor Imaging Area18.0 x 13.5 mm (ASCOM)
18.2 x 13.7 mm (active)
Test SoftwareAscom Driver 1.0.0.10/CCDCap 2.50B unless otherwise noted
Gain at 0% Setting0.62 e-/ADU
Gain at 100% Setting0.13 e-/ADU
Read Noise8.5 e- RMS (overscan - measured in EZCAP1.3)
11 e- RMS (Active Sensor, maximum gain)
12 e- RMS (Active Sensor, minimum gain)
Readout Banding1.3e- Peak to Peak (2% readout noise)**
Dark Current0.09 e-/pixel/sec @ 5C
0.01 e-/pixel/second @ -10C
22 hotpixels @ 5C
8 hotpixels @ -10C
2 hotpixels @ -25C
LinearityExcellent (refer graph)
[/b][/font]* From examining actual images in EZCap
** Some minor horizontal banding was noticed in highly stretched dark frames
*** Based on pixels that have attained a value of 25,500 e- (point at which signal becomes non-linear)

Re: Looking for bias, dark, flat of qhy9
« Reply #6 on: June 14, 2009, 04:31:03 PM »
Here is the transfer graph refered to in the above table.

Terry

Re: Looking for bias, dark, flat of qhy9
« Reply #7 on: June 14, 2009, 04:33:19 PM »
This is a crop of single bias frame, stretched and enlarge 200%:


Re: Looking for bias, dark, flat of qhy9
« Reply #8 on: June 20, 2009, 07:46:58 AM »
Hello,

Thanks for your work.
This camera looks good !