UPDATE 7/18/13: I updated this test to use a newer optimized version of RawToDNG which significantly reduces the aliasing of the original video. If Alex from Magic Lantern adds any additional quality improvements to this feature, I'll just update it here so everyone can see the current status of Dual ISO Raw.
I added an additional comparison of Dual ISO footage vs Normal Raw "Denoised" vimeo.com/70511941
This is not a scientific test but just rather something to give people an idea of the quality improvements to Raw video using this new feature.
Testing methods used...
Camera: 5D Mark III (shot 24fps at 1080p)
Dual ISO was set to use 100 and 1600 ISO.
Normal Raw ISO was set to 100.
Footage was shot in a dimly lit room with both a tungsten lamp and dark areas in the frame.
Shot handheld to reveal any moire or aliasing which may increase using Dual ISO feature.
Raw was converted to DNGs using the newest rawtodng.exe.
Postprocessing via Adobe Camera Raw using identical settings for both Normal Raw and Dual ISO shots...
Exposure was brought up a bit to +2.8
Noise Reduction 0,
All other settings were at 0 or default values
Exported via After Effects to intermediate AVI files (Cineform 444 Filmscan 1)
Edited in Premiere Pro CS6 and rendered to H.264 1080p (10Mbps).
This test was designed to be a worst case scenario. Bright light in a dim room including fabric textures to help reveal moire. The reduction of shadow noise is dramatic to say the least. Without Dual ISO the footage would have been unusable. But it does come at the cost of increased moire/aliasing, something which Alex from Magic Lantern clearly indicates in his technical documents describing the new feature. Clearly, many scenes won't exhibit the level of moire/aliasing shown in this test, so one just has to be mindful of the content of your scene and weigh that against the need to retain both highlight and shadow information when the dynamic range of the scene if greater than 12 stops. But when you are unable to properly light a scene to even out the exposure, the Dual ISO feature allows you to bring up the shadows in post significantly with very little increase in noise. Regarding any minor resolution decreases that are supposed to accompany this feature, I think that is a moot point... the footage wouldn't even be usable in my test scenario without the Dual ISO feature (short of lighting the scene properly). I'm sure in some usage scenarios, the benefits will outweigh any disadvantages.
Oh.. and for all those asking, the reason the Normal Raw footage is so noisy is that it was shot at ISO 100 in a dim room and the shadows were significantly boosted in post. ISO 100 was used in order to retain all of the highlight detail of the lamp. The whole point of this feature is that you can now significantly boost the shadows in the Dual ISO footage with very little noise penalty.
Thanks to Alex from Magic Lantern for all his generous work and contributions. Greatly appreciated.
I used the "Standard" as the control, and shot scenes where the shadows were slightly crushed. Using the same exposure, I just changed Picture Style to see how much of the crushed blacks were restored.
The "Neutral" setting is what I've been using for my other videos.