ZWO ASI991MM Pro Monochrome Cooled SWIR Astro Camera - ASI991MM-P

The ZWO ASI991MM Pro is a SWIR (Short Wave Infrared) camera that uses the Sony IMX991 InGaAs (Indium Gallium Arsenide) sensor featuring a wide micron range from 0.4um to 1.7 um.   Since this speciality sensor captures short wave infrared light, it is applicable for photometric measurement, optical communication, and work in optical and laser laboratories.  

SWIR cameras are used in astronomy to observe objects that are cooler or more redshifted than those in visible light as well as objects obscured by dust, etc.

The ZWO ASI991 SWIR operates in the 400nm to 1800 um wavelength, allowing it to penetrate fog and thin clouds at night or image stars in the daytime.

ZWO ASI991MM Pro SWIR Camera Highlights...

Please Note: All ZWO cooled (Pro) cameras will require an external 12V DC power source in order to operate properly and run the TEC cooler. You have three options:

1. Buy a 12V DC Power Supply with a minimum of 3 amps; we recommend the ZWO power supply listed at the end of this page.

2. Buy the ASIAir and use the DC Out port to run your camera.

3. Buy an external 12V DC battery like the Celestron PowerTank or equivalent.

It is important to know that your computer may not recognize your camera or operate correctly if you just use the USB 3.0 cable alone. You will want to connect whichever 12V DC power source you choose into your computer as well.

Zero Amp Glow

Traditional CMOS sensors produce a weak infrared light source during operation which is quite often seen in the corner of uncalibrated images as tell-tale signs of amp glow.  You won't have to worry about amp glow with the ASI991MC Pro, even when using high gain during long exposure images, however, as ZWO uses zero amp glow circuitry.

Readout Noise

Readout noise is generated in the amplifier on the chip that converts the stored charge of each pixel into an analog voltage to be quantified by A/D conversion.  The lower the readout noise is, the better the image SNR.  Compared to traditional CCD SWIR cameras, the ASI991MM Pro keeps its readout noise at a really low level.

Two-Stage Cooling

With its built-in two stage TEC cooling, the ASI991MM Pro can lower the sensor temperature to 30-35 degrees Celsius below ambient temperature, greatly reducing dark current generation and sensor noise.  

It is recommended that you use this camera at low temperatures to get better imaging performance.

Specifications

Sensor:  Sony IMX991 InGaAs

Sensor Size:  3.2 x 2.5mm, 1/4"

Resolution:  656 x 520

Pixel Size:  5um

ADC:  12-bit

Read Noise:  21.27e

Cooling Temperature:  35ºC

DDR3 Buffer:  256MB

Transmission Interface:  USB 3.0

Frames Per Second:  144

Full Well:  127ke

Quantum Efficiency:  80%