Looking at input-referred read noise spectra across ISO ranges

I’ve added code to see how input-referred read noise from dark field images varies as the ISO setting of the camera is changed. For the GFX 100II, with 600×600 pixel crops away from the center of the sensor:

You can see the following things:

• Decrease in input-referred read noise when the conversion gain changes.
• Relative ISOlessness between the conversion gain changes
• Artificial noise reduction applied at the three highest ISO settings.
• Periodic noise from the PDAF pixels.