QHYCCD QHY268M Pro I Monochrome CMOS Camera

Sony IMX571 Sensor: 26MP at Native 16-Bit Resolution

At the core of the QHY268M Pro is the back-illuminated Sony IMX571, an APS-C format sensor with a 6252x4176 pixel array. Unlike cameras that use 12-bit or 14-bit conversion, the QHY268M Pro employs a true, native 16-bit A/D converter. This delivers access to all 65,535 grayscale levels, producing exceptionally smooth tonal gradations in bright nebulosity and preventing posterization in heavily processed images.

1.1e- Read Noise and Confirmed Zero Amp Glow

The QHY268M Pro is engineered for clean data acquisition. In its high-gain modes, read noise drops to an exceptionally low 1.1e-, allowing faint structures to be captured with shorter sub-exposures. Combined with a dark current of just 0.0005 e-/pixel/sec at -20°C and QHY's verified zero amplifier glow circuitry, your calibration frames become simpler and more effective, resulting in a cleaner final image with less processing effort.

Dual Full Well Modes: 51ke- Standard vs. >80ke- Extended

The camera features two distinct readout modes to match your target. Standard Mode offers the lowest read noise and a deep 51,000e- full well capacity, ideal for faint deep-sky objects. For dense star fields or bright nebulae like the Orion Nebula (M42), Extended Full Well Mode increases the capacity to over 80,000e-, preventing bright stars from saturating while preserving color and detail. This mode comes with a slight increase in read noise to a still-low 5.3e-, representing a deliberate trade-off for greater dynamic range in a single exposure.

2GB Buffer: 6.5 FPS Full-Frame and High-Speed ROI

A substantial 2GB DDR3 memory buffer ensures reliable, drop-free imaging, even over slower USB connections. This allows the QHY268M Pro to sustain a 6.5 FPS capture rate for full-resolution 16-bit images. For planetary or lunar imaging, you can select a Region of Interest (ROI), such as a 480-line window, to boost the frame rate to 110 FPS in 8-bit mode, perfect for lucky imaging techniques.

-35°C Cooling and a Compact 14.5mm Back Focus

The dual-stage thermoelectric cooler achieves a stable delta of -35°C below ambient temperature, drastically reducing thermal noise for clean, long-exposure narrowband imaging. The camera body features a heated optical window to prevent dew formation. With a back focal length of just 14.5mm, the QHY268M Pro accommodates complex imaging trains, providing ample space for filter wheels, off-axis guiders, and other accessories while maintaining correct spacing.

QHY268M Pro vs. ZWO ASI2600MM Pro: Key Differences

Both cameras use the excellent Sony IMX571 sensor and offer 16-bit A/D conversion. The primary differences lie in their hardware implementation.

• Image Buffer: The ZWO ASI2600MM Pro includes a 512MB DDR3 buffer. The QHY268M Pro provides a 2GB DDR3 buffer, offering four times the memory for increased stability during high-speed captures or on systems with heavy USB traffic.
• Back Focus: The ASI2600MM Pro typically has a 17.5mm back focus. The QHY268M Pro features a shorter 14.5mm back focus, which can be advantageous for imagers using accessories with long optical paths, like certain off-axis guiders or adaptive optics units.
• Connectivity: The QHY268M Pro includes a 2x10Gigabit Fiber port in addition to USB 3.0, offering an alternative high-speed connection path for advanced remote observatory setups.