QHYCCD QHY990 PRO II SWIR InGaAs Scientific Camera

The QHY990 Pro II: Scientific Imaging from 400nm to 1700nm

The QHY990 series are scientific short-wave infrared cameras with high sensitivity across 400 nm to 1700 nm. The Pro II is the QHY990 with two 10 Gigabit fiber interfaces and two CameraLink interfaces added to USB 3.0, and the series model with liquid cooling.

Applications include SWIR astronomy imaging and photometry, daytime star observation, optical communications, laser, scientific research and optical laboratory applications, while biological fluorescence imaging and environmental monitoring are fields that need low dark current.

Sony InGaAs Sensor: 1296 x 1032 Resolution with 5.0µm Pixels

At the core of the QHY990 PRO II is a Sony InGaAs sensor with a resolution of 1296 x 1032 pixels. The 5.0 µm pixels give an 8.28 mm sensor diagonal (1/2 inch format), and the sensor is Class 1.

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

77% Peak QE, 112,000e- Full Well, and 12-bit ADC

The QHY990 PRO II's sensor delivers a peak Quantum Efficiency of 77% at a wavelength of 1200 nm, with a broad spectral response from 400 nm to 1700 nm.

Typical full well is 112,000 electrons and typical read noise is 135 e-, measured after bias frame FPN calibration. Data is digitized by a 12-bit ADC (4,096 levels), and dark current is 64.6 e-/pixel/sec at -30°C and gain 0.

Hybrid Cooling Down to 80°C Below Ambient

InGaAs sensors typically have larger dark currents than silicon-based sensors, so powerful cooling is necessary. The QHY990 PRO II uses a dual-stage TEC cooler with air cooling and liquid cooling. QHYCCD applies its own cooling and sealing technology from its astronomical cameras rather than Sony's built-in sensor cooling. At 25°C ambient, the measured QHY990 dark current is 1477.26 e-/pixel/s with the sensor at +10°C and 250.55 e-/pixel/s at -10°C.

• Air Cooling: The dual-stage TEC reaches 35°C below ambient (test temperature 20°C).
• Liquid Cooling (Water): With normal water, 45°C below ambient.
• Liquid Cooling (Chilled): With cold liquid, 60°C to 80°C below ambient.

66 FPS via USB 3.0, 10G Fiber, and CameraLink

The QHY990 PRO II reaches 66 FPS at full resolution at both 8-bit and 16-bit output. A 128MB DDR2 buffer holds frames during transfer.

There are three computer interfaces:

• USB 3.0: The standard interface, shared with the QHY990.
• Dual 10Gigabit Fiber: Two 10 Gigabit fiber interfaces.
• Dual CameraLink: Two CameraLink interfaces, Pro II version only. A trigger-in socket (RCA type, opto-isolated) is also fitted.

C-Mount Interface with 17.5mm Back Focus

Designed for straightforward integration, the QHY990 PRO II features a standard C-mount optical interface. The back focus is 17.5 mm, and 1.25 inch support is available with an adapter. QHYCCD offers SWIR lenses for the QHY990 and QHY991.

The camera also includes an integrated 25mm filter holder positioned within the optical path. The 25 mm size is a very common filter type for lab applications; the holder supports D=25mm and D=25.4mm filters.

Imaging the Infrared Sky Beyond 1000nm

For astronomers, the QHY990 PRO II's sensitivity from 400 nm to 1700 nm opens a unique observational window. Its applications include SWIR astronomy imaging and photometry and daytime star observation.

QHYCCD's QHY990 samples include a daytime image (16mm f/1.4 SWIR lens at f/2.8, 1200-1800nm filter, gain 0, 1.3ms) and a night-sky image (same lens at f/1.4, 29 stacked 2-second frames at -11°C, dark frame calibrated). Its Orion Nebula first light, taken with the QHY992 and a 1200-1700 nm filter, shows core details that differ from visible light.

QHY990 Pro II vs. QHY990, QHY991, and QHY992

The QHY990 PRO II is part of a series of SWIR cameras from QHYCCD, each tailored for different needs. It shares the QHY990's sensor and adds interfaces and liquid cooling.

• vs. QHY990: Both models use the same 1.3 MP Sony IMX990 sensor with 5.0 µm pixels and achieve 66 FPS. However, the standard QHY990 offers only a USB 3.0 interface and weighs about half as much (520g vs. 1kg), The QHY990 PRO II adds dual 10G fiber and dual CameraLink ports.
• vs. QHY991: The QHY991 uses a smaller 0.4 MP sensor (656 x 520) but with the same 5.0 µm pixel size. It reaches 123 FPS via USB 3.0.
• vs. QHY992: The QHY992 offers the highest resolution in the series with a 5.32 MP sensor (2592 x 2056) and smaller 3.45 µm pixels. Its frame rate is 48 FPS at 8-bit via USB 3.0, and its full well 30ke- (LG AllPixel Mode).

Control via the QHYCCD All-In-One Pack

The QHY990 PRO II is controlled through the QHYCCD All-In-One software pack, which includes all necessary drivers and core software. Install the pack before connecting the camera. It contains:

• System Drivers: Essential for the computer to recognize and operate the camera.
• EZCAP_QT: QHYCCD's own software for device tests, update management and basic image capture, with temperature control and an Image Task Planner for sequences.
• ASCOM Drivers: For ASCOM programs; QHYCCD uses MaxIm DL as its example. N.I.N.A connects through the QHY plugin or the ASCOM driver.
• SharpCap: included in the pack, authorized by SharpCap, in 32-bit or 64-bit.

After installation, the camera can be connected to a 12V power supply and then to the computer. Use 64-bit software such as SharpCap x64 and N.I.N.A x64.

12V Power and a 1kg Lab-Ready Chassis

The QHY990 PRO II requires a stable 12V DC power supply to operate its powerful TEC and electronics. The camera consumes up to 40W when the cooler is running at 100% power. A stable voltage between 11V and 13.8V is critical; a voltage drop from long or thin cables can cause the camera to reboot or function incorrectly, especially under high cooling loads.

The camera weighs about 1 kg. Holes on both sides near the front plate, normally plugged by a screw with an o-ring, accept a desiccant tube if moisture fogs the chamber, and two M5 drying interfaces at the front end work with drying tubes and a circulation pump for cyclic drying, with the cooler off and the camera back at room temperature first.

Your First Session with the QHY990 Pro II

Getting started with the QHY990 PRO II is a straightforward process. First, have a 12V supply that holds 11V to 13.8V at the camera under a 40W load. Before connecting the camera, install the QHYCCD All-In-One pack with the drivers you need (ASCOM, SharpCap).

Once the software is installed, follow these steps:

1. Connect the 12V power cable to the camera.
2. Connect the camera to your computer using one of the data cables (USB 3.0 is recommended for initial setup).
3. Launch your chosen imaging software (e.g., EZCAP_QT, N.I.N.A.). The camera should appear in the device selection menu.
4. Connect to the camera and navigate to the thermal controls. Enable Auto and set a target temperature (QHYCCD's example is -10°C); the sensor typically reaches it within 2 to 3 minutes. Raise TEC power gradually to avoid thermal shock.
5. Set your exposure time, gain, and capture area, then take your first image.