Is IMX 294 more sensible than binned 2x IMX 178 ?

Hi Sam,

Hi all,

I'm always interested in IMX 294 color camera to replace my QHY5III 178 C.

Is there someone who have tried to compare an ASI 178 or QHY 178 C in binned 2x

mode and ASI 294 in bin 1x on the same DSO targets ?

I would like to know if IMX 294 is really more sensible in "real life".

Many thanks for your help.

Albéric

they are very close to each other if you do lucky imaging

the QE difference is very small

the advantage of 294 is full well

Hi Sam,

On Cloudy Night forum, there is "heated debates" about these new sensors.

For full well parameter, I agree, IMX 294 is far better. But it's not the

most important parameter for short exposure DSO imaging. Sensitivity in

very low lights is the main parameter.

The SNR1s parameter is maybe the most consistent information to compare

"on the paper". IMX294 SNR1s value is same as IMX385/IMX 224 (the best

available now, 0.13/0.14 lux). IMX178 in bin 1x is far away (0.46 lux).

With a quick calculation, in bin 2x mode, the read noise will be decrease

by 2. If shot noise have the same behaviour (right or wrong ??), the SNR1s

should be divided by 2. So near 0.23 lux in bin 2x.

And IMX294 is still ahead.

https://www.sony-semicon.co.jp/products_en/IS/sensor0/technology/snr1s.html

The best solution would be a comparison between the 2 cameras : ASI 178 in bin2x

mode and ASI 294 in bin 1x mode. Same target, a bright planetary nebula, short

exposure (1 to 3 seconds), same exposure, same gain, same telescope, same F/D,

same seeing, and enough signal offset (brightness) to avoid any lost of signal.

A set of 100 Raw images addded without processing. And we compare the limit

magnitude on faintest stars, for exemple.

Albéric

we did such indoor test and found they are very close to reach other if you exposure below 10s

385 is the best among them