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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

grading red footage

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scott william

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Would it be fair to say that most Red footage is graded red colour and red gammer? Or do you prefer to grade from Redlog?
 
If you want to start something like an online voting, here's mine: REDColor 2 and REDLogfilm.
 
Best starting point for grade is REDLogFilm, REDColor2. If you're doing a more video style grade, use REDGamma2.

Graeme
 
Here's what i get out of all of this.....

If you are sending to a colorist OR you are a colorist and you know your art....Redcolor2 - Redgamma 2 or RedlogFilm....this will give you a very flat canvas for you or your colorist to work off and perform best color correction.

If you are NOT a colorist and you are NOT sending to a colorist and merely an amateur (like myself) you can get a more saturated and finished look by grading in Redcolor2 & Redgamma 2. As you work in RCX and do your corrections...you have a near finished product (except for say your black/white balancing).

....that said, i'll work in whatever format allows me to tweak colors where i need them. If i really need to work a shot, then i go to the flatest look possible. If i think the shot looks good in R2 & RG2, then i leave it there. And so much depends where you are going with this later.....most of what i do goes to tv land and will NEVER see a colorist.....so it better look good or they either won't use it or won't use me again.
 
Graeme,
Can you please explain the difference between Adobe 1998 and RedColor2?
Which one has a larger color gamut / supports a larger number of color shades?

After all, most digital cameras can record stills in AdobeRGB (instead of the limited sRGB).
And most professional 10bit LCD monitors roughly cover the entire AdobeRGB gamut.

So where exactly does RedGamma2 stand?

 
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Cameras don't record stills in Adobe1998 or sRGB though - they're raw development parameters just as our REDColor and REDColor2 are. REDColor2 is compatible with REC709 (which is very similar to sRGB) but with larger gamut.

Indeed cameras, being non-colorimetric devices don't even have a well defined colour space anyway. They don't have distinct primaries the way a display does. Internally we do all the colour space conversions referenced back to XYZ so as to ensure compatibility with whatever output colour space you choose and to avoid any premature clipping.

The colour spaces you reference in your image are all monitor spaces. They have little to do with camera colorimetry.

Graeme
 
Graeme,
OK, so the defined color space is RAW development parameters.

So what are the RGBW parameters of RedColor2?

Here are the AdobeRGB 1998 parameters:


I'm asking because of the differences I see between RedColor2 and Adobe 1998 in RCX, and it's interesting to know how RedColor2's gamut looks like.
EDIT: It would be nicer if you posted a chroma diagram with both RC2 and AdobeRGB on it, so we can visually see the difference between the two.
 
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Although RG2 is described as a colour space, that's not entirely how it works. It's not a display colour space like Adobe1998 or REC709. It's a REC709 compatible camera raw data conversion space, and although the difference may appear subtle in terminology, it means I can't really answer your question as the math works differently.

Graeme
 
Thanks guys,

I've been using red colour 2 and Redlog. Still on the M sensor here however. And it's still great.
 
Graeme Nattress said:
Best starting point for grade is REDLogFilm, REDColor2. If you're doing a more video style grade, use REDGamma2.

Graeme
Click to expand...

graeme,
would you choose redlogfilm to grade for Rec709 delivery ?
or you like redlogfilm only using a print Lut on top of it ?

seems that many many use redlogfilm no matter what , i am wondering ,than how they make that log curve linear ...using a log to lin lut ? shaping a custom curve ? because using lift gamma and gain should be a wrong approach on a log image ...

thanks

g
 
Gabriele Turchi said:
seems that many many use redlogfilm no matter what , i am wondering ,than how they make that log curve linear ...using a log to lin lut ? shaping a custom curve ?
Click to expand...

Yes, and yes. Whichever way works best for you. A LUT is accurate and simple. A curve is more flexible because you can change it. In either case, you want to have a correction prior to the LUT, and probably a correction after the LUT as well. That way you can adjust for mis-exposed material and still use the "standard" LUT. If you're interested, I explain all of this on my blog at mikemost.com.
 
Yes Mike, yes Gabriele.

Only thing to point out is that the LUT (or custom curve) makes the Log into video gamma (not linear).

Graeme
 
Graeme Nattress said:
Yes Mike, yes Gabriele.

Only thing to point out is that the LUT (or custom curve) makes the Log into video gamma (not linear).
Click to expand...

While that is, of course, true, I've gotten to the point where I'm not going to continue fighting the misuse of the terminology on this one, particularly when it's reasonably clear to me what the poster is intending - which in this case is Red footage displayed properly on a monitor of some sort. In the circles that you and I often travel in, the distinction is important and purposeful. With civilians - even reasonably well trained civilians - it doesn't seem to register, so I've stopped trying to stress it.
 
On the other hand, I've not stopped :-) It must be that I've never taken off my tech editor hat.

Graeme
 
M Most said:
While that is, of course, true, I've gotten to the point where I'm not going to continue fighting the misuse of the terminology on this one, particularly when it's reasonably clear to me what the poster is intending - which in this case is Red footage displayed properly on a monitor of some sort. In the circles that you and I often travel in, the distinction is important and purposeful. With civilians - even reasonably well trained civilians - it doesn't seem to register, so I've stopped trying to stress it.
Click to expand...

Personally I really appreciate when proper distinction is made as the difference between logarithmic and linear gamma is complicated enough as it is (I find it even harder to understand in the case of RedLogFilm/Log/Linear) It seems to me that RedLogFilm is closer to literal Linear gamma in this case and video gamma would be the conversion of RedLogFilm to a gamma of 2.4 (or whatever your preference is). What I'm unsure of is what word to use to describe this transformed gamma since the fact that it isn't linear doesn't make it logarithmic by default right?
 
REDLogFilm is pure log, and can be described in the form y=A log (Bx + C)
Linear is of the form y=Ax+C, although for it to be linear to light we want C=0
Video gamma is of the form y=Ax^C, although more complex versions are used where a small linear section is placed near x=0.

Graeme
 
Graeme Nattress said:
REDLogFilm is pure log, and can be described in the form y=A log (Bx + C)
Linear is of the form y=Ax+C, although for it to be linear to light we want C=0
Video gamma is of the form y=Ax^C, although more complex versions are used where a small linear section is placed near x=0.
Graeme
Click to expand...

That would explain why Mike is suggesting to apply the LUT after the initial grade is applied, or at least in a place that allows you to make corrections before the LUT. Thanks Graeme!
I guess the next question would be with ACES you should be applying LUT transformations before the grade, correct? So you would go REDLogFilm > ACES > corrections > Linear > grade as needed/wanted or am I thinking about this the wrong way where ACES would theoretically replace the Linear transformation?
(I should say that all of my deliveries right now are for REC709 but I'm trying to get in the habit of having a master grade in the proper color and gamma space that could have LUTs applied on export to various destinations with maintained fidelity and it seems ACES is the way that workflow is headed...)
 
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