Author Topic: Random band noise QHY-9  (Read 9677 times)

janori

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Random band noise QHY-9
« on: May 18, 2009, 02:03:19 PM »
Hello,

"First light" of my new QHY-9
12x300"   Gain=5   Offset=114   bin1x1  -20ºC  High Speed not active
Capture EZCAP



A horizontal bright noise band appears at the bottom of the image

If I make a dark-frame, a band noise is visible, but only sometimes and with a random position
I show two consecutive darks frames (histogram stretched and image resample):



There are solution or is necessary replace the camera?

Regards

Thanks



hercule1939

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Re: Random band noise QHY-9
« Reply #1 on: May 18, 2009, 10:33:23 PM »
Great first light!
Random "noise", you are seeing, is cosmic rays.
You'll deal with them by using sigma clipping or similar method while stacking.

J-P

janori

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Re: Random band noise QHY-9
« Reply #2 on: May 18, 2009, 11:04:45 PM »
Thanks hercule

But this noise band is not a cosmic ray. Is a perfect horizontal band who appears in 99% of images, and the position is random
I show again three crops of dark-frames:



Regards

Gama

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Re: Random band noise QHY-9
« Reply #3 on: May 18, 2009, 11:06:21 PM »
This looks like electrical noise from some source.
Try another power supply.
Is the supply your using REGULATED ?.

What is the power supply rating and brand ?.

Theo

janori

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Re: Random band noise QHY-9
« Reply #4 on: May 18, 2009, 11:14:29 PM »
Hello gamma

I have tried a Celestron Power-Tank and a battery car, in two different computers, in my house and in the mountain... and always the noise band.

Regards

Gama

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Re: Random band noise QHY-9
« Reply #5 on: May 18, 2009, 11:20:46 PM »
May be worth sending back for a check up.


Theo

QiuHY

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Re: Random band noise QHY-9
« Reply #6 on: May 19, 2009, 01:52:52 AM »
Hello,

           This is the USB transfer  noise.  I think you are not using the newest EZCAP1.3 .This verison is just in the discuss forum->software board.
Because the new QHY9 slow the readout speed, So old software can not match the timing. The SDRAM must buffer all image then transfer, but
with old EZCAP because the buffer time is shoter so the transfer is staring before the whole image buffered into SDARM.

            Reference link:  http://qhyccd.com/ccdbbs/index.php?topic=1244.0


          The solve solution is :   using the lastest software and drivers.

Best regards,
« Last Edit: May 19, 2009, 01:59:34 AM by QiuHY »

janori

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Re: Random band noise QHY-9
« Reply #7 on: May 19, 2009, 11:25:50 AM »
Hello QiuHY

I think that I'm using last drivers:

QHY9FW Ver 0.0.9.0
QHY9IO Ver 1.30.0.0

and last software EZCAP 1.3:



I have used MaximDL too (plugin release 090208), and the same one occurs

Regards

QiuHY

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Re: Random band noise QHY-9
« Reply #8 on: May 20, 2009, 12:24:35 AM »
Hello,
     Is it this one:   http://qhyccd.com/ccdbbs/index.php?topic=1426.0

     They are both v1.3. The difference is : the new has three download speed options , the old has only two options.

Best regards,

Gama

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Re: Random band noise QHY-9
« Reply #9 on: May 20, 2009, 12:37:43 AM »
Qiu, have you updated the main download Home Page with the newer version too.

Theo

janori

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Re: Random band noise QHY-9
« Reply #10 on: May 20, 2009, 02:38:24 PM »
Thanks for reply QiuHY

My supplier says that I have the last software. I have three speed options: high, normal and slow.
I have tested the software that you show, and the same one happens.

With normal speed a dark noise band appears, and with a slow speed the noise band is more bright:



I have noticed that the mechanical shooter closes a few seconds later than the image has finished, during the download of the image. Sometimes this delay is bigger and the noise band appears in other zone of the image (more up). Is possible an electrical interference during USB discharge caused by shooter electrical signal?

Best regards
« Last Edit: May 20, 2009, 03:50:51 PM by janori »

janori

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Re: Random band noise QHY-9
« Reply #11 on: May 20, 2009, 02:42:59 PM »
Excuse me, but is very difficult for me to speak in english

Sorry!

QiuHY

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Re: Random band noise QHY-9
« Reply #12 on: May 20, 2009, 09:45:47 PM »
Hello,

            Then it should be some noise come from other part . Can you send a 1:1 stretched image on buttom of the band(inlcudes part of the band) so that I can anyalze it .
You can send the cropped FIT file to my email box qhy9@qhyccd.com


Best regards,

janori

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Re: Random band noise QHY-9
« Reply #13 on: May 21, 2009, 10:24:18 AM »
OK QiuHY

I send you

Best regards

QiuHY

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Re: Random band noise QHY-9
« Reply #14 on: May 21, 2009, 11:39:46 PM »
Hello,
        I did some test in lab. Here it is also this problem. In long exposure the camera's internal clock is not match the computer's clock. So at the end of exposure the buffer is starting at first, ,then transfer is staring before end of buffering.
So I will add more buffering time for it. This is just the EZCAP problem, not the camera hardware. I will fixed this bug soon.

Best regards,