【Cocoon Nebula】

By Simon Todd, with QHY183M

QHY183 is a model designed for astrophotography beginners. It exhibits excellent sensitivity and low noise, with the back illuminated 183 having higher sensitivity and somewhat higher resolution.  It is well suited to planetary and deep-space imaging particularly when mated with the CFW3 filter wheel. This model has two-stage thermal electric cooling of the sensor to about minus 40 degrees C below ambient for maximum reduction of dark current noise in long exposures.

QHY183 incorporates QHY’s Anti-Amp Glow technology to significantly reduce typical CMOS amplifier glow to a minimum, allowing excellent calibration by subtracting a dark frame.

QHY183 utilizes the Anti-Dew features common to the QHY COLDMOS cameras. Dew is moisture that condenses from the air onto the outside of the chamber window.  Frost is water vapor that freezes when it comes into contact with the inside of the chamber window or the surface of the sensor.  QHY has nearly 20 years of experience designing cooled cameras and these models benefit from those years of anti-dew and anti-frost design experience.  To help prevent dew from forming on the chamber window heating elements are built into the light shield just above the chamber. To avoid frost from forming inside the chamber a desiccant tube is provided that can easily be attached by the user to the outside of the camera when needed to dry the internal atmosphere of the chamber and remove any built-up moisture.

QHY183 models can be used as guiding devices, too.  The opto-isolated guiding port is a standard ST-4 configuration using an RJ11 style Jack.  A guiding cable is included with each camera.

The 183 with its smaller higher resolution sensor is a good match to short focal length telescopes or for imaging smaller dim objects through a large scope.  The larger 163 gives a greater field of view and would be a good choice for imaging larger areas of the sky such as nebula or when coupled to a longer focal length telescope to take greater advantage of the scopes full field.

The QHY183M is a one-inch, 20 Megapixel back-illuminated monochrome CMOS camera with a peak QE of 84%.  The pixel size is 2.4um, yielding high-resolution with modest size telescopes.  The camera is capable of producing 15FPS@20 Megapixels.  It has a two-stage TEC that cools the sensor to -40C to -45C below ambient.  The ADC is 12-bit / 16-bit with 1e- read noise!  The computer interface is USB 3.0 and exposure times can be set from 50us to 3600sec.