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Hi there,

Amazing work. I made some modification to the script. You could enter liveview between c2 and c3 so it is using electronic first curtain to reduce vibration.

However, I ran into a problem with the scripting on camera.burst(count)

LUA interpreter raised an error message
"attempt to call a nil value (field 'burst')"

Is this associated with version of magic lantern? I'm using the latest nightly build for my 6D

If you are asking about the registers that can be tweaked, you can find them documented in the iso-regs module:
https://bitbucket.org/hudson/magic-lantern/src/iso-research/modules/iso_regs/iso_regs.c#cl-583

(we simply changed them, written down the observed effects, and then guessed what they might do)

OK, correct me if my understanding is wrong.
1. CMOS gain is the analog gain inside the sensor itself. So amplified signal in high iso will avoid noise contamination when the signal wire run across the PCB until it hits PGC/ADC chip?
2. All other ADTG gain are to fine tune the voltage range input to ADC?
3. Digital Gain is used when a larger aperture is selected?
4. From that image, it appear the saturation point is analog adjust but black level is offset in post processing?

This really contradicts what I understand in a Sony Exmor sensor.

In Sony sensor, the OFFSET 0x1F register sets the input number to bias voltage. It calibrated the ADC bias voltage so that the dummy pixels would be read out as your OFFSET value. During the first 50 rows, sensor will continue refine this bias level to within 1 ADU using dummy readout. Regardless of OFFSET and gain setting, the saturation point always reach 16382. It's like adjusting the intercept of a linear function.

Dark current will be registered on optical black pixels and all the active pixels as well. So it will show an elevated bias. This is where it differs from Canon. Somehow it clamped the dark current to bias level.

The stock Nikon firmware adjust the dark current to 0 using those optical black pixels in post processing. Thus saturation level will be pulled down. I'm curios to know if it's possible for Canon to disable dark normalization as well?

This is interesting since some Nikon DSLRs also uses external ADCs. D700/D3 uses AD9974.

Hi all,

This is astronomer from NikonHacker. I had been investigating the Sony sensor for months. Could someone explain to me what's the difference between white offset and black level offset in this thread? I'd expect the black level and gain are the only 2 values to fix a straight line. Some tests done by others suggested Canon did offset to correct dark current and bring it back to 2048. I thought this is done digitally as the saturation point for dark frame is not 16383. But it seems contradict some of the posts here where you guys suggest an additional feedback loop during optical black pixel read out.

Sony sensor has all the analog chain integrated so it's much simpler. A register to set black level and 4 gain registers for each color channels. The sensor output spans from 0 to 16382. All the rest are done in digital domain, such as color channel scaling, black level clip (dark current correction), large aperture light loss scaling, etc.

Best,
astronomer