Where is middle gray when shooting ML Raw?

[QuickHitRecord]

Specifically, I am looking for the percentage (trying to calibrate a light meter with my 5D3).

Does this number change when using BMDFilm color space in Resolve as a starting point for a grade and if so, to what percentage?

Thanks.

EDIT: Audionut's response here: http://www.magiclantern.fm/forum/index.php?topic=11331.msg110307#msg110307 answers the first part of my question, but I'm still trying to figure out whether I can calibrate my light meter according to BMDFilm.

[Audionut]

You probably don't really want to.  When shooting raw, you really only have two limits to be concerned about. 

The saturation level, above which things are overexposed, and your accepted noise level, below which things have to much noise.  Ideally, you probably want to push things as bright as possible during the capture phase (ETTR), for maximum SNR (quality).  In post process, it's very easy to tone map things to the desired brightness level.

[QuickHitRecord]

@audionut So, if I'm understanding what you are saying, striving for in-camera consistency will take a toll on dynamic range in post, because raw footage needs to be exposed to the right for best results.

I hadn't thought of it that way.

[dubzeebass]

I always expose to the right then bring it down in post. May as well maximize the inputs and attenuate as needed. That's how we mix sound on a board too!

[QuickHitRecord]

As an experiment, I shot a Sekonic Exposure Profile Target II which gave me a wide range of exposure values in the frame. Following the ETTR hint on the raw histogram put the spot meter box (hovering over the middle gray chip) at -3.7EV. Looks good in post so far, so I'm going to go with it.

[Audionut]

When I shot this scene (which has a fairly large dynamic range) for this, Canon dumped the middle grey @ -3.3 EV, which is 10% (log2(100/10)) luminance (Canon is somewhat known for underexposing to protect highlights), and 0.85 EV under 18% (log2(18/10)) luminance.




http://xritephoto.com/ph_product_overview.aspx?ID=824&Action=Support&SupportID=5159
http://dpanswers.com/content/tech_zonesystem.php#tzh
http://www.rawdigger.com/howtouse/calibrate-exposure-meter-to-improve-dynamic-range

At -3.7 EV, you are around 8% luminance, 1.22 EV underexposed.