QHYCCD QHY990 Series SWIR Camera

Sony InGaAs Sensor: 400-1700 nm Imaging with 77% Peak QE

At the heart of the QHY990 is a Sony InGaAs sensor for scientific short-wave infrared imaging. Its spectral response begins in the visible spectrum at 400 nm and extends deep into the SWIR band to 1700 nm. Its applications are SWIR astronomy imaging and photometry, daytime star observation, optical communications, laser, scientific research and optical laboratory work, as well as low-light detection and biological imaging.

The sensor uses Cu-Cu (copper-to-copper) interconnect technology, which gives very low FPN noise and a low defect pixel ratio.

Scientific Signal Character: 112,000e- Full Well Capacity and 12-bit ADC

The QHY990 has a typical full well capacity of 112,000 e- per 5.0 µm pixel, which leaves room before bright areas saturate.

The analog signal is digitized by a 12-bit ADC, which provides 4,096 levels. Typical read noise is 135 e-, measured after bias frame FPN calibration, and dark current is 64.6 e-/pixel/sec at -30°C and gain 0. The electronic global shutter ensures that every pixel begins and ends its exposure simultaneously, so it avoids rolling shutter distortion of moving subjects.

Advanced Thermal Management: ΔT 35°C Air Cooling for Dark Current Suppression

InGaAs sensors typically have larger dark currents than silicon-based sensors, so powerful cooling is necessary. The QHY990 uses a dual-stage TEC cooler that reaches 35°C below ambient (test temperature 20°C).

QHYCCD measured the effect at an ambient temperature of 25°C: the QHY990's dark current was 1477.26 e-/pixel/s with the sensor at +10°C and 250.55 e-/pixel/s at -10°C, so even a 3 second exposure shows far less noise when cooled. QHYCCD applies its own cooling and sealing technology from its astronomical cameras rather than Sony's built-in sensor cooling.

QHYCCD writes that the QHY990 Series supports both air cooling and liquid cooling, with liquid cooling reaching 45°C below ambient with normal water and 60°C to 80°C below ambient with cold liquid.

High-Throughput Imaging: 66 FPS at Full Resolution via USB 3.0

The QHY990 reaches a maximum frame rate of 66 FPS at its full 1296 x 1032 resolution. The rate is the same at 8-bit and 16-bit output. A 128MB DDR2 memory buffer holds frames during transfer over USB 3.0.

QHYCCD's listed applications include:

• SWIR astronomy: Imaging and photometry.
• Daytime star observation: Daytime stars have been captured with the QHY991, and a QHY990 daytime sample was taken with a 1200-1800nm filter.
• Optical communications and laser work.
• Scientific research and optical laboratory applications.

Optical & Mechanical Integration: C-Mount Interface, 17.5mm Back Focus, and 25mm Filter Holder

The QHY990 has a C-mount front with a 17.5 mm back focus, and 1.25 inch support is available with an adapter. QHYCCD offers SWIR lenses for the QHY990 and QHY991. The body is 92.5 mm long and weighs 520 g.

QHY990 Series cameras include a 25 mm filter holder; the 25 mm filter is a very common type for lab applications, and the holder supports D=25mm and D=25.4mm filters. A trigger-in socket (RCA type, opto-isolated) is also fitted.

SWIR Applications: Daytime Astronomy and Industrial Analysis

QHYCCD's sample images show what the camera records. A QHY990 daytime sample used a 16mm f/1.4 SWIR lens at f/2.8, a 1200-1800nm filter, gain 0 and a 1.3ms exposure. A night-sky sample used the same lens at f/1.4 and filter: 29 stacked 2-second frames at -11°C sensor temperature, dark frame calibrated.

In astronomy, applications include SWIR imaging, photometry and daytime star observation. An Orion Nebula first light image was taken with the QHY992 and a 1200-1700 nm bandpass filter, showing core details that differ from visible light.

QHY990 vs. QHY991 & QHY992: Choosing the Right Sensor

The QHY990 is part of a series of cameras that share the same core technology but use different Sony InGaAs sensors.

• QHY990 (This Model): Features the IMX990 sensor with a 1296 x 1032 resolution and 5.0 µm pixels. It reaches 66 FPS at full resolution with a typical 112ke- full well.
• QHY991: Uses the IMX991 sensor, which has the same 5.0 µm pixel size but a lower resolution of 656 x 520. It reaches 123 FPS at full resolution.
• QHY992: Employs the IMX992 sensor, which offers a much higher resolution of 2592 x 2056 but with smaller 3.45 µm pixels. Its full well is 30ke- (LG AllPixel Mode) and its frame rate 48 FPS at 8-bit.

Software Ecosystem: QHYCCD All-In-One Pack, ASCOM, and Third-Party Support

QHYCCD provides a comprehensive software package to control the QHY990. The All-In-One Pack includes system drivers, EZCAP_QT capture software, and ASCOM drivers for broad compatibility with third-party astronomy software. SharpCap is also included in the pack, authorized by SharpCap, and N.I.N.A connects through the QHY plugin or the ASCOM driver.

To get started, install the All-In-One pack, then connect the camera to its 12V supply (40W at 100% cooler power) and to the computer with a USB 3.0 cable. Use 64-bit software such as SharpCap x64 and N.I.N.A x64. Once installed, software like SharpCap or N.I.N.A. will recognize the camera, giving you full control over exposure, gain, cooling, and capture settings. The ASCOM driver lets ASCOM programs such as MaxIm DL control the camera.