Extended full well mode in IMX571 cameras

in PlayerOne Poseidon, 71 ke full capacity available right from the beginning

in ASI 2600MC Pro, cloudynights

apr 2023

now ZWO added the "extended full well mode" to 80 ke- full well, to ASI2600MC Pro ONLY ( IMX571 sensor), and 15 FPS ( raw8)

in Touptek, INDILIB forum

in QHY268 IMX571

QHY offers four readout modes for the 268:

0 (photographic mode)  amplifier switch to lower noise at gain=26

1 (high gain mode).  amplifier switch to lower noise at gain = 56

2 (extended full well mode). Higher noise, but full well around 80Ke-

3 (extended full well mode 2CMSIT) Full well around 80Ke-, but readnoise 1.3x lower than mode 2

For mode 1, HQA measured 2.85e-/ADU readnoise at 0 gain setting.  This yields a system gain of 0.77e-/ADU, and a linear full well depth around 62K counts or 48Ke-.  He considered this the best combination for photometry, as fairly short exposures will have enough sky signal in broad-band filters that the sky noise will dominate over the readnoise, and you can stack images without a noise penalty.  Using gain setting 58, I get a readnoise of 1.26e- and a system gain of 0.32e-/ADU.  This gives a linear full well of 62K counts or about 20Ke-.  He considered this gain setting to be pretty much ideal for spectroscopy, where the background is always low and readnoise becomes a much bigger noise source.

cloudynights

astrobin

cloudynights risingcam sensor analysis update in 2023