The QHY 5-III 174C is a popular colour camera for guiding and planetary imaging. It uses the SONY IMX174, a 1/1.2-inch Exmor sensor with a global shutter that, differently from the rolling shutter, allows to expose all pixels at once. In this way the whole sensor is exposed at the same time and there is no "transient" readout. Compared to the other QHY III cameras, the 174 has a large sensor [13.27mm diagonal] that is recommended for Moon and Solar imaging.
The wide sensor combined with large 5.86 µm pixels makes this camera the perfect match for off axis guiders, especially in long focal length telescopes. For example, a 12" RC f/8 combined with the QHY 5-III 174C results in a pixel scale of 0.5"/pixel that is still manageable, especially if at binning 2x2. Also, the sensor size helps to find a suitable guiding star in off axis guiders where the field of view is limited. As for all QHY III cameras, the backfocus is only 11mm which is advantageous for instruments where the focusing travel is limited such as in off axis guiders.
The QHY III cameras can reach a data transfer speed of up to 350 MByte/s via USB3.0 port, ideal for high speed imaging of fast-rotating planets. For the 174C it translates to an output of 138 FPS at full resolution and up to 490 FPS at selected ROI.
The metal body and the advanced thermal design aim to dissipate the heat generated by the sensor and electronics and therefore to reduce the noise. The QHY5-III cameras include a heavy duty 5-pin socket for a solid connection between the camera and other devices. The package includes a 5-pin-LEMO-to-RJ11 adapter for autoguiding with the ST4 cable.