Dual ISO Test - 100 + 800 

Magic Lantern Software Canon 7D + 100mm IS L 

 

Click to expand 

 

The Dual ISO process takes one image processed half at ISO 100 the other at ISO 800 then interlaces them in lines.

 

This outputs a .CR2 raw file that need 'de-interlacing' using "CR22HDR"  creating a DNG. 

 

Take the DNG into Photoshop like any other raw file and edit using ACR. 

 

As shown above the single ISO when boosted reveals horrible banding and noise on the LEFT. Needing more exposure compensation to be visible. 

 

On the RIGHT the DUAL ISO allows for much greater control over exposure requiring less boosting to gain greater dynamic range.