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New QHY294C Now Available at Deep Space Products

CMOS imaging
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#1 EFT

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Posted 06 December 2018 - 08:30 PM

QHYCCD_Logo_t.png

 

QHY294C_2_t.PNG

 

The QHY294C is now available
Based on the Sony IMX294C, the QHY294C camera has an 11.6 Megapixel, 4/3-inch, back-illuminated, cooled, color CMOS sensor with
14-bit A/D, 1.6e- read noise near unity gain and 1e- read noise at highest gain. At lowest gain the read noise is 6.8e-. The QHY294C full
well capacity is nearly 65,000 electrons with 4.63um x 4.63um pixels, almost the same as an interline CCD camera with 9um pixels.

 

High Sensitivity
The QHY294C has high QE, with a peak QE in the green estimated at 75% or more and nearly 70% at H-alpha. The high QE, medium
sized pixels and extraordinary low read noise and low dark current all combine to produce a camera with very high sensitivity, perfect
for astronomical imaging. In addition, the back-illuminated structure provides greater full well capacity and therefore greater dynamic
range than front illuminated sensors with similar architecture.

 

Dual Gain Auto Switch - HGC/LGC MODE Boosts Low Light Performance
The QHY294C's CMOS sensor has a dual gain mode, HGC (high gain) and LGC (Low gain). The QHY294C will switch the two modes
automatically when the gain is set to 1600 you will get the benefits of the ultra-low read noise (1e- to 1.6e-) of the HGC mode and a
full well capacity of about 14.5ke- at the switch point setting.

 

Super Low Dark Current 0.005e-/p/s @ -20C
The QHY294C uses QHYCCD's proprietary low dark current control technology. This technology significantly reduces the dark current
noise in our CMOS cameras. The QHY294C has super low dark current as a result, lower than many CCD cameras, allowing for very long
exposure times

 

High Resolution 14-bit Frame Rates
The QHY294C produces 16.5 frames per second at high resolution (11.6 MP) with 14-bit A/D. Higher rates are achieved for regions of
interest, for example, 21 FPS at 4K resolution, 41 FPS at 1080 lines, 87 FPS at VGA, 156 FPS at 240 lines, etc.

 

256MB DDR3 Image Buffer
The QHY294C has an internal 256MByte high speed DDR3 image buffer. This is more than enough for one frame and it significantly
reduces any issue of lost frames due to a busy computer CPU or slow USB communication packet errors.

 

Anti-Dew Technology
The QHY294C benefits from more than a decade of cooled camera design experience. QHYCCD has implemented full dew control
solutions. The optical window has a built-in dew heater and the sealed CMOS chamber is protected from internal humidity
condensation.

 

Flexible Adapters
The QHY294C has the same body design and mechanical interface and the QHY163. It has a short back focal distance allowing the use
of QHYCCD's 0.5mm-27mm spacers (step size 0.5mm) for flexibility in setting up your optical train.

 

DSP_Patch_Logo_3_Very_Small_t.png


Edited by EFT, 06 December 2018 - 08:30 PM.


#2 DmitriNet

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Posted 06 December 2018 - 09:42 PM

I have hard time understanding

how is it possible to have >65,000 electrons FW and 14-bit output

 

It seems "the true" full well capacity is about 14.5ke  (~65000/4) and ">65,000" differs from what is advertised.

 

Did any one actually measured saturation curve of this chip at unity gain?



#3 bobzeq25

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Posted 06 December 2018 - 09:59 PM

I have hard time understanding

how is it possible to have >65,000 electrons FW and 14-bit output

 

It seems "the true" full well capacity is about 14.5ke  (~65000/4) and ">65,000" differs from what is advertised.

 

Did any one actually measured saturation curve of this chip at unity gain?

It's 65K electrons at gain 0, which is 4 electrons per ADU.  My Atik 460 does a similar thing in 16 bits, the fwc is 16K electrons, the gain is 0.25 electrons per ADU.  Common practice in the industry.


Edited by nicknacknock, 07 December 2018 - 03:06 AM.

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#4 mvas

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Posted 06 December 2018 - 11:13 PM

Full Well Capacity defines the amount of charge ( electrons ) an individual pixel ( photodiode ) can hold before saturating the read output.

FWC is dependent upon the GAIN setting.


Edited by nicknacknock, 07 December 2018 - 02:17 AM.

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#5 DmitriNet

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Posted 07 December 2018 - 10:50 AM

FWC is dependent upon the GAIN setting.

That's what I have trouble understanding.

Amplifier --- gain is its characteristic --- cannot determine how many e- can be inside a pixel without saturating it.  Or am I missing something about CMOS technology here?



#6 nicknacknock

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Posted 07 December 2018 - 12:45 PM

All,

 

Kindly note that the Vendors Forum is for Vendors to post about products and services and for members to ask questions about these products and services.

 

For general questions unrelated to the specific thread, please start a new thread in the appropriate forum (in this case, imaging or equipment).



#7 bobzeq25

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Posted 07 December 2018 - 12:46 PM

That's what I have trouble understanding.

Amplifier --- gain is its characteristic --- cannot determine how many e- can be inside a pixel without saturating it.  Or am I missing something about CMOS technology here?

Here was your stated issue.  "how is it possible to have >65,000 electrons FW and 14-bit output"

 

Gain cannot determine how many _electrons_.  What it can determine is where you hit the digital 111..... limit in 14 bit ADU.  At 4 electrons per ADU, you can get to 65,000 electrons and still measure them with 14 bits.  There will be some quantization, but, because of noise, stacking many frames will smooth that out. 

 

At higher gain fewer electrons will be needed to reach the digital limit, and clipping will occur before 65,000 electrons accumulate.

 

Needless to say, my post crossed nickacknocks.


Edited by bobzeq25, 07 December 2018 - 12:47 PM.



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