ZWO ASI 1600GT Mono camera

A cooled mono CMOS camera with a built-in filter wheel and a stylish square design

WO has become a well-established brand in the CMOS camera marketplace; over the last decade it has produced models for all types of imaging. We are used to seeing the cylindrical shape and red colour of its deep-sky cameras, but now ZWO has launched two new ‘GT’ models that break with tradition. Here, we take a look at the ASI 1600GT M, a mono camera with a built-in filter wheel.

After opening the 1600GT M’s box, we were presented with a square-shaped camera; it’s quite a bit larger than a normal ZWO model – with a stylish heatsink back case, two cooling fans and two handles – and finished in anodised red. On the bottom we found a USB 3.0 and two USB 2.0 sockets, plus a ‘power in’ socket and a new ‘power out’ socket that can carry 12V to other devices. There is also a red LED power light for when the camera is active, although this has been reduced in size and isn’t as bright as on other cameras. The front cover of the camera is black and has four screws; unscrewing these reveals a filter wheel for 1.25-inch filters with space for five.

Some care must be taken when installing filters as ZWO is quite specific about the size of thread on these, so it’s worth checking the company website

Z(https://astronomy-imaging-camera.com) before installing them; if they are too big the filter wheel could get damaged before you even start imaging. You will also need to visit the website to download the drivers for the camera and the ASCOM driver for the filter wheel (ASCOM is an industry-standard interface that allows different pieces of astronomical equipment to communicate), as these are no longer included on software discs. If you are installing the drivers on a PC, you will also need to have the ASCOM Platform installed there; this will enable you to name the filters and control the filter wheel with software.

The 1600GT mono sensor is a 4/3-inch type with a resolution of 4,646 x 3,520 pixels, while the camera itself has a 256MB DDR3 memory buffer to help with download times. Setting the camera up for imaging is quite straightforward as the adaptors that give 55mm back focus are included in the box.

Test conditions

For the first time in a while we had just two hours of clear sky in a whole month. Luckily, we were able to extend our time with the camera; if we hadn’t this review might have been rather short! One of our main concerns was to see if there would be any vignetting. This is when the brightness of an image falls away >