Thursday, January 23, 2014

Blackmagic vs Magic Lantern (Round 4)

Magic Lantern have gone and done it [here we go] again!

First it was "Magic Lantern finds RAW Video!",  back in May of last year the Magic Lantern team found a "2K" (1931 x 1288) resolution 14bit Raw image that they thought might be used to get Raw video but that didn't stop the Camera Blogs from what I called polluting the internet with uneducated speculation with claims of the 5D mark III surpassing all it's competitors in the DSLR and Cinema world with amazing raw video when in fact it was only 720p for 2 second runtimes. (Note that the ML team eventual got there with with 5D3, the blogs just preemptive reported it.)
Now the blogs are a buzz once again with another misunderstood Magic Lantern development.  The newest tag is "Magic Lantern increases Dynamic Range to 15 stops!"; that's similar to the footage out of a RED Epic and is 3 stops higher than the Canon C500, cameras that cost 10x more, but again the truth is actually far from the headlines.  Hopefully the misinformed blogs will make the appropriate corrections and start paying closer attention to facts rather than buzz words.  

What Magic Lantern has actually done is found the "Digic Registers" or "control points" for the camera's ISO and modified them to get a higher Dynamic Range but no where near the 3 - 4 stop jump to 15 stops that's being reported.  The actual numbers are about half a stop; here is a list of the Dynamic Range stops with the stock firmware versus with the new Magic Lantern feature:

5D3 Canon ML ISO
100 10.98 11.36
200 10.90 11.32
400 10.79 11.23
800 10.59 11.01
1600 10.16 10.59
3200 9.53 10.015
6400 8.60 9.16
12800 7.82 8.40

This in it's own is a great improvement, helping the Canon 5D mark III to catch up to its competitors!  Many of the recent DSLR sensors have surpassed Canon's 11 stop Dynamic Range with the latest Nikon and Sony cameras reaching 14.4 stops.  This still can't match those "DR monsters" in low ISO shooting but in high ISOs (where the 5D Mark III is already known for it's clean Image to Noise ratios) this new feature can match the Dynamic Range of the Nikon D800* at ISO 6400 (9.17 vs 9.16 stops) and even surpasses it at ISO 128,000 (8.40 vs 8.16 stops).
So what's all this talk about 15 stops then?  Well the poster who brought this to the blogs attention mentioned that when combining this new feature with Magic Lantern's older "Dual ISO" feature (that works by combing ISO 100 and ISO 1600 to push shadows while pulling highlights) the result would be similar to 15 stops of dynamic range.  Which most just read as "Magic Lantern, blah blah blah, 15 stops of dynamic range, blah blah, RAW!".  Though it is technically capturing more "shades of grey" than just using ISO 100 or ISO 1600 alone; the reason why it's not a practical choice is that the "Dual ISO" process actually reduces the very detail in the highlights and shadows that you are trying to retain and adds extra artifacts such as aliasing, it'll work great for a chart where the shades are uniform but not very effective for every situation in the real world.
Now for the real question, how close does this dynamic range now come to the Blackmagic Cinema Cameras with their claim 13 stops?  Recent tests have already shown that the Canon 5D3's dynamic range in Raw video was very close, I'll wait to do some tests but based on the numbers I'm pretty sure they are now equal now.