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Old 17-05-2016, 03:15 PM
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gregbradley
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Join Date: Feb 2006
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Quote:
Originally Posted by Camelopardalis View Post
Who said the 1600 refuses to capture photons if set to low gain for 10 minutes?
Exactly. The sample narrowband images of a bunch of short Ha images versus 1 15 minute image showed the 15 minute image as being nicer overall to my eye.

The camera can do both which is the edge over CCDs.

This sensor is really somewhat old in the sense that the current cutting edge Sony sensors have copper wiring (instead of the usual aluminium and what this means is 4X faster read time and probably less noise, plus a thinner stack meaning it can take light at greater acute angles) and backside illuminated with the circuitry on the back gaining an extra 40% imaging area for the pixels.

Backside illuminated sensors are what most new Sony sensors are using.
This is CCDs increases QE up to the 90-95% band. I am not sure what it does for Sony's. I don't think it is that much though. My Sony A7r2 has all this technology in its 42.4mp sensor and its a pretty amazing sensor. Not ideal in its current state for astro though as it has some colour noise in the shadows at high ISO long exposure (long exposure noise reduction gets rid of it but still).

In addition there are lots of subtle tricks like 3 stage ADC where the as the ISO rises at a certain point this kicks in and drops the noise further.

Some Sony sensors have a built in memory buffer chip on the back of the sensor to improve how many images they can hold.

Sony is also working on some exciting new types of CMOS sensors. One is able to control individual exposures per pixel, they have a curved full frame sensor already. They are supposed to be working on a similar sensor to the Foveon sensor with RGB pixels at different depths on the same pixel site.

Global shutters are not far away either.

Greg.
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