QHYCCD

Minicam5F Technical tests

Minicam5F Technical tests
« on: May 28, 2015, 02:52:59 pm »
I will publish here the technical tests of minicam5F.

I admit ideas for possible tests to be performed.

- FPS test: PC Desktop, Intel Quad core 9900 2.66Ghz, 4GB Ram, Windows Vista  Home Premium S.P.2, 32bits, HD7200rpm, with EZplanetary 3.81. No drivers or installation problems.





« Last Edit: May 28, 2015, 03:18:25 pm by Maximo Suarez »

Re: Minicam5F Technical tests
« Reply #1 on: May 28, 2015, 02:55:16 pm »
- Cooler: Cooler on 28.8ēC to -18ēC 90s. Cooler off -18ēC to 30ēC 90s.
No traces of moisture or condensation in a full night of use, with the cooling 100%
The temperature rises a 3ē once it starts to be used intensively.
Delta about 45ēC at 100% cooling.

The second graph shows the cooling efficiency by the percentage of power.

The third picture contains, in the first row Darks to 0%, 50% and 100% of the cooling power, in the second row are the bias and in the third row the darks-bias.
You can see how to increase the power of the cooling columns and horizontal lines pattern noise increase, to correct the bias darks, vertical lines disappear but the pattern of horizontal lines is maintained.
Both darks as bias were obtained in the same series of images without disconnecting the camera or leave the EZCAP program, whenever the cooling rate was changed waited a while for the temperature to stabilize and calibrated the FPN in advanced options EZCAP. Gain 0.

A new test in the fourth image trying to get horizontal pattern random noise is hidden in the calibrated images, evidence to be used gain from 2 or 3 to avoid this noise.

It is recommended then use the camera without reaching 100% power cooler, 60-70% is good, for changes in night temperature and intensity of use and sacrifice some SNR, gain up 2 -3.

« Last Edit: June 12, 2015, 03:52:20 am by Maximo Suarez »

Re: Minicam5F Technical tests
« Reply #2 on: May 28, 2015, 03:04:02 pm »
Gain/Noise (DevStd): This camera have 5 gain positions 0,1,2,3,4. First graph take darks 60s at this gains. Second image take lights at the same exposure and gains 0, 2, 4. Third, the relationship between the signal / noise and gain, it seems clear that it is better to use low gains for better signal to noise ratio is obtained.



« Last Edit: May 31, 2015, 01:18:54 pm by Maximo Suarez »

Re: Minicam5F Technical tests
« Reply #3 on: May 28, 2015, 03:05:56 pm »
-Noise (DevStd), cooler 100% and no cooler 1, 10, 30, 60, 300 y 600s


Re: Minicam5F Technical tests
« Reply #4 on: May 28, 2015, 03:09:22 pm »
- Linearity:

easybob95

Re: Minicam5F Technical tests
« Reply #5 on: May 29, 2015, 12:43:44 am »
Hello Maximo,

could you comment your results ?

Alain

Re: Minicam5F Technical tests
« Reply #6 on: May 29, 2015, 03:54:34 am »
- FPS Test: All right, speed capture and recording disk is expected for this camera. You can hardly exceed 100fps images of Jupiter, Mars or Saturn, the exposure time between 15-30ms for a good histogram is limiting, USB 3.0 or higher fps is useful for the moon or the sun.

- Cooler: Excellent response, it responds quickly to changes in temperature and maintained at constant temperature the chip. There is no sign of moisture or condensation is great news, even without using the silica.

- Gain / noise: For deep sky I prefer to use the gain to 0, considerably less noise is obtained. however it is to perform a slope test, averaging 10 images the same time exposed to different gains, and evaluate S/N in both.

- Noise: It is only the obvious, much less noise cooling without it.

- Linearity: Great news for me and for everyone who engages in variable stars or exoplanets and comets or asteroids astrometry, the camera response is linear up to nearly saturation level, this means that can be used for photometry and astrometry .

They are still more tests to do.

easybob95

Re: Minicam5F Technical tests
« Reply #7 on: May 29, 2015, 05:34:54 am »
Many thanks for the highlights !

Re: Minicam5F Technical tests
« Reply #8 on: May 31, 2015, 09:10:49 am »
I edited the second message cooler with a new graphics and images of darks and bias.

QiuHY

  • *****
  • 4366
    • View Profile
    • Email
Re: Minicam5F Technical tests
« Reply #9 on: May 31, 2015, 09:23:13 am »
Hello,
       FPN calibration has two stage:

1. Hardware FPN calibration. This can be done by click the "FPN calibration" Button. But maybe the current version this button has an issue and it may no response. You can try another method:  Change the gain to another gain , wait some seconds and change back. The FPN will be calibrated by hardware.

2. Software FPN calibration. The is still a little FPN noise remain after hardware FPN calibration. Then we can use the dark frame or bias frame to calibrate it. The important thing is that the light frame and dark frame must be take at the same time.  Because this is the "remain" FPN noise. Once the hardware FPN calibration run a time, the remain FPN noise will change.

It means if you capture the dark frame today and capture the light frame tomorrow, You can not use the dark frame to calibrate the light frame. Because you may reboot computer , or close EZCAP, or reconnect the camera during this two days.


Best regards,
Qiu Hongyun
Qiu Hongyun

Re: Minicam5F Technical tests
« Reply #10 on: May 31, 2015, 01:24:08 pm »
I edited the third message Gain/noise with a new graphics and images.

Mr Qiu thanks for clarifying that error in the software, hopefully soon be resolved.

Re: Minicam5F Technical tests
« Reply #11 on: June 06, 2015, 07:25:50 am »
- Filters: Using a Bathinov mask and focusing initially with L filter, the filter is changed without changing the focus to see the difference between them. The LRG filters remain practically equal in focus, the filter B should be clearly refocus.
QHYCCD filters LRGB 12mm.

Edit: Newton 14" f4,5 + Coma Corrector, bad test, I repeat without correction of coma
« Last Edit: June 08, 2015, 05:14:01 am by Maximo Suarez »

QiuHY

  • *****
  • 4366
    • View Profile
    • Email
Re: Minicam5F Technical tests
« Reply #12 on: June 07, 2015, 11:38:27 am »
Hello,

        For the the Blue focus issue. Since the LRGB is use the same glass. And the height is the same. I am not sure it is due to the index of the glass. Maybe the color shift issue?  Blue wavelength focal plane is not the same?

Best regards,
Qiu Hongyun
Qiu Hongyun

Re: Minicam5F Technical tests
« Reply #13 on: June 08, 2015, 05:12:22 am »
Hello:
Please wait for a new test, this test is with coma corrector lens and is best done with mirrors alone, my fault.

The problem here is atmospheric diffraction, the blue channel is always displayed worse than red and green, a parfocal filters must have the same focus for all wavelengths, but this is a very complex problem because even if used a Newton telescope or any other based only on mirrors, atmospheric dispersion affects differently depending on the object's height above the horizon and the wavelength of light.
How parfocal filters are made ?, I guess varying the thickness or density using different glass for each filter.

Refractor telescopes for I fear it is impossible to make parfocal filters serve for them all, because each one has a different design and color correction.

However, this is a minor issue, as much as a manufacturer promises a parfocal filter is always just refocusing either planetary or deep sky.

Regards
Maximo

Re: Minicam5F Technical tests
« Reply #14 on: June 12, 2015, 03:56:16 am »
I edited the second message again, cooler, with a new image to hide the random horizontal noise.