New color ZWO ASI224, ASI185 and ASI178 cameras available for preorder
Very low read noise combined with high quantum efficiency have created a very good and promising color cameras
ZWO is pushing three new cameras with Sony IMX color sensors - ASI224, bit bigger ASI185 and ASI178 with smaller pixels. The preorder prices are around 365 - 400 EUR.
ASI224 is a color camera with Sony IMX224 sensor (1/3" diagonal, 3,75 micrometer pixels). Key advantage of this camera is extremely low read noise measured between 1,5e - 0,75e depending on used gain. Such low read noise increases SNR of captured frames allowing achieving even better planetary images. Beta testers did notice this low noise performance and were able to produce very good images. You may find more about those noise measurements on cloudynights.
ASI185 is a color camera with bit larger 1/1.9" sensor. The Sony IMX185 seems to give bit higher read noise (3,3e - 1,4e), but that's still low when comparing to older generations of CMOS sensors.
ASI178 is also a color camera, equipped with Sony IMX178. With 1/1.8" diagonal and 2,4 micrometer pixels it has a 3096 x 2080 frame. This sensor uses backside illumination to make those small pixels perform better. Read noise was measured in the range of 2,2e - 1,4e.
All of those three camera use USB3.0 interface and a clear protection glass. Previous color ZWO cameras used IR/UV cut protection glass, but those cameras have very good IR performance. There are even bandpass infrared Saturn images taken with ASI224 (methane band filter) and they look as good as from a mono camera. The cameras are available for preorder on astronomy-imaging-camera.com and astromarket.org.
Emil photographed Whirpool galaxy using ASI174 and ASI224. Marc Delcroix shot Saturn in visible and infrared (methane band) light, while Darryl photographed Saturn from a big telescope in Australia.
As you can see new color CMOS sensors from Sony present a new level of performance. Aside of providing very good planetary images on millisecond exposures those sensors can also venture into DS object imaging - but instead of classical few minutes exposures high gain cameras do that on few second exposures (although with some trade-offs).
ZWO is also working on their own atmospheric dispersion corrector as well as on actively cooled versions of those three cameras.