DNxHD better than RAW? In this case I say yes.

[Gavin Greenwalt]

So... I shot the same thing twice with my Scarlet. Once from one camera angle and once from the other. By virtue of a storage miscalculation I only have DNxHD from a Black Magic Hyperdeck Shuttle of one angle and RAW of another. But I discovered an interest little quirk while intercutting.... the DNxHD looks better than the raw. At first this puzzled me and then it became obvious... it's a low light situation. Both shots are REDLogFilm but the RAW is at 10:1 (for long record time) but the DNxHD is recording off of an uncompressed feed. The noise characteristics are clearly in favor of the DNxHD since it's recording a fine grained noise as opposed to the Scarlet footage which has clear 'clumpy' blue noise.

I can't guarantee this will be true of all situations but that's one more +1 in the Hyperdeck category for me for long form, low light performances if I can't record at least 6:1.

I would like to do some clear testing now that this has come to my attention and ensure there isn't some odd variable between the two that's different. But both were processed at 800ISO, RLF RC3. Both should be 270* shutter and 23.976fps. Both should be F2.8. When processed the same they both look to match in luminance. Has anyone done any comparison shots between recording off of SDI vs RAW? Seeing as it was two set-ups it's entirely possible that there is another variable at play. Not sure what I might have changed though.

 

[J Taylor]

can you post an r3d for us to play with

 

[Gavin Greenwalt]

Unfortunately not (shot for a performance group so they own rights), I'll make a shareable r3d tomorrow under controlled conditions and a matching DNxHD. It should be a better test anyway.

 

[John Marchant]

10:1 is ugly up close when there's a lot of detail, and scraping the barrel for photons amounts to the same thing due to the random noise pattern. The SDI must feed from prior to compression in the signal chain then?

 

[Lee Saxon]

Misleading title!! This is not DNxHD vs RAW, this is highly compressed vs uncompressed.

 

[Mike P.]

This has been confirmed/repeated. The HDSDI/HDMI down convert is cleaner because it skips the compression altogether. It's most noticeable at high ISOs and/or under-exposed portions of an image. The other advantage for Scarlet users is that at 4k, with look around enabled, you also get the full 1.3x/5k FOV (and 5k-to-1080p down conversion)...

The problem is your limited to 1080p and you're baking in your image.

 

[Gunleik Groven]

Misleading title!! This is not DNxHD vs RAW, this is highly compressed vs uncompressed.

LOL...
As if DNx is uncompressed...

But the compressions are different and probably suit different scenarios...

 

[Chuck Z]

This is why I've been advocating lossless RAW compression from RED for a long time (although it appears 3:1 may satisfy this request).