.
To answer the "what else" question, I summarized :
- the
Top-8 Cameras with lowest Detection-Threshold < 0,01% @ 0dB SNR, from DxOmark
same as in my previous post, ordered by
Measured-ISO
- the
Top-8 Cameras with lowest Noise-Levels in 5 min. Dark-Frames
from
The Sensor Noise DB. – Brendan Davey Photography
ordered by their
Noise-Mean-Value
Pentax K-1, the
95 Top Measured-ISO with a Detection-Threshold of 0,009% @ 0dB SNR
+ the 2nd Noise-Mean-Value just behind the Pentax K-5 in 5 min. Dark-Frames (+5ev)
The very Low Dark-Current levels of the Sony imx071 explain the Pentax K-5 Top position
= the 1st lowest Noise-Mean-Value in the 5 min. Dark-Frames (+5ev) test
the Dark-Current Chart is from the Zwo Astro imaging site :
https://astronomy-imaging-camera.com/products/asi-cooled-cameras/asi071mc-pro/
Same Sony sensor, at a $1700+ price !
Then the Asi071(K-5) compared to the Asi294 and Asi1600
= two Astro-Cams with 4:3 ~22,7mm diagonal sensors
High ISO settings are mandatory to lower the Exposure Time to 1 sec. or less
this to cancel the Atmospheric Turbulence effect with long FL.
the only way to operate with Lucky Imaging !
But finally, what do you lose from
Base-ISO to ISO 10K :
- Dynamic Range value from
14 ev down to 7 !
- Tone Values from
16384 down to 128 !
- SNR to be Half the Base ISO SNR
- your RAW File Size doubles
- for the same final IQ, you'll have to Stack much more RAWs...
- with Dark-Frames !