QHYCCD QHY268C Color

Sony IMX571 Sensor: 26 Megapixels and Native 16-Bit Depth

The core of the QHY268C is its 26MP APS-C format sensor, providing a large field of view and high resolution from its 6252x4176 pixel array. The 3.76µm pixels are well-suited for a wide range of focal lengths, from short refractors to long Schmidt-Cassegrains, balancing resolution with sensitivity. Unlike cameras that upscale 12-bit or 14-bit data, the QHY268C employs a true, native 16-bit A/D converter, sampling the signal at 65,535 distinct levels for exceptionally smooth tonal gradations in bright nebulae and galactic cores.

Dual Readout Modes: 80ke- Full Well and 1.1e- Read Noise

The QHY268C offers multiple readout modes to match your target. For dense star fields or bright objects like the Orion Nebula (M42), the Extended Full Well Mode provides a massive 80ke- capacity, preserving color and detail in the brightest stars without saturation. For faint, low-contrast targets like distant galaxies or molecular clouds, High Gain Mode drops read noise to just 1.1e-, maximizing the signal-to-noise ratio in your individual sub-exposures and revealing the faintest details.

Zero Amp Glow and -35°C Cooling for Clean Exposures

Long-exposure deep-sky astrophotography demands thermal control, and the QHY268C delivers on two fronts. The dual-stage TEC cooler achieves a typical thermal depression of -35°C below ambient, drastically reducing dark current to just 0.0005 e-/pixel/sec at -20°C. Critically, the camera's circuitry is engineered for Zero Amplifier Glow, completely eliminating the characteristic brightening at the edge of the frame that can contaminate long exposures and complicate calibration. This results in cleaner, more uniform raw frames that require less aggressive processing.

1GB DDR3 Buffer and 50 FPS High-Speed ROI

While designed for deep-sky imaging, the QHY268C is also a capable high-speed camera. An internal 1GB DDR3 memory buffer prevents dropped frames during data transfer, a common issue when imaging from less powerful computers or over long USB cables. At full 26MP resolution, it captures 6.8 frames per second. By selecting a Region of Interest (ROI), such as 480 lines for planetary imaging, the frame rate increases to 50 FPS, fast enough for lucky imaging of Jupiter's cloud bands or fine lunar details.

Imaging Train Integration: 14.5mm Back Focus and Anti-Dew Heater

The QHY268C is designed for straightforward integration into complex optical trains. It features a short back focus distance of 14.5mm, providing ample space for filter wheels, off-axis guiders, and other accessories while still meeting the strict spacing requirements of modern correctors and reducers. An integrated anti-dew heater on the optical window prevents frost and condensation during humid nights, ensuring your imaging session is not cut short by changing weather conditions.

QHY268C vs. ZWO ASI2600MC: Buffer Size and Readout Modes

Both the QHY268C and the ZWO ASI2600MC are built around the excellent Sony IMX571 sensor, offering nearly identical core imaging capabilities. The primary differences lie in hardware implementation and features.

• ZWO ASI2600MC Advantage: The ASI2600MC is typically lighter (approx. 700g vs. 810g) and has a different body shape which may be preferable for certain mounting configurations, particularly on smaller telescope packages.
• QHY268C Advantage: The QHY268C includes a larger 1GB DDR3 buffer (compared to 512MB in the ASI2600MC), providing greater protection against dropped frames during high-speed capture or with slower PCs. QHY also offers more granular control over readout modes, including the 80ke- Extended Full Well Mode, which is a distinct advantage for imagers targeting bright, high-dynamic-range objects.