Welcome to our community

Be a part of something great, join today!

Log in
  • 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 :)

Apple Color: Gamma & Color Space setting

D

Dustin Cross

Well-known member
Joined
Mar 6, 2007
Messages
1,240
Reaction score
0
Points
0
Location
Austin, Texas
Website
www.sandust.com
Aloha,

What Gamma and Color Space should I use in Apple Color for grading R3D files? When I work in Redcine I normally use Redspace and Redspace, but in Color I have access to my HD CRT studio monitor which is 709 HD color space.

What settings should I use in Apple Color?

Most likely we will be outputting to HDCAM SR tape in 1080p.

It looks like Gamma 709 and Color Space Redspace looks correct, but I am wondering what experts recommend.


Thanks,
Dusty
 
I tend to stick with Redspace color space setting the whole time w/ Redspace gamma if the footage is very well shot or time is crucial even for HD delivery. But if time is not an issue, I use Rec709 gamma for the HD delivery.
 
I would add a question here, so what is gamma vs colorspace story? I mean what is the difference and what should I conider on each of them?
 
Grading means to transform the look of your footage into the colour space you look at with the aim to make it look nice in this particular colour space. REC709 is the colour space in which your HD-Monitor is calibrated. If you grade for film-out there are LUTs that translate the film colour space into Rec 709 or whatever.

Think of RedSpace or Red's REC709 as a LUT. Red developed those LUTs for the users because they look meaningful on a REC709 calibrated device, hence the name. The beauty of RAW is the possibility to grade off the linear RAW data. If you want the full information there is no reason to apply a curve/LUT already before you start grading. Doing so means grading twice.

If you like RedSpace/REC709 as a foundation to build your final grade upon - do so. But don't forget that those LUTs will force the look of your grading into a certain direction.


Hans
 
Hans, very interesting, but if you do not mind lets go deeper in this, so if you think about red's footage, and do not apply any color space, what will you get? you still have some default color space right? you say that Grading meand tranforming the look into a color space you are goin to view it on, this mean media like HD television, film or something like that, but then, what are you transforming it from? also, we all know that rec709 is colorspace for HD right?! but if I grade my footage in redspace, is it not going to look the same on HD or what is the it about? and again in color now and earlier in redcine, we had to choose two things, 2 pulldown menues, in one we saw cameraRGB, redspace etc, and in the other we had redcine, rec709, redlog, pdlog and so on. so what are those two pulldown menues about? what is the difference if I have redspace/redspace or redspace/rec709, or cameraRGB/redspace and etc. hope this is not too complicated, but for sure it is very interesting
 
Hi Levan,

IMHO, I find it Red's naming of their LUT's rather unlucky because naming a LUT with the the word "space" tends to confuse people.

Just to sort this out: If I look at ANY picture with my laptop I view it in "Hans' Laptop-Space" which utilizes a non-calibrated RGB Gamma 2.2 - close to REC709 though.

If I go down to my lab and look at the same picture on the Sony CRT with my BlackMagic Decklink card via HD-SDI I view this picture in a (kind of) calibrated REC709.

Now there are LUTs. They are build for various reasons. They can mimic film on a REC709 device or they translate linear to log or they make certain linear RGB data look nice on a REC709 device. In Red's case RedSpace is a LUT that makes in RGB debayered Red footage look nice and vibrant on monitors that unitlize the colour space REC709. On a Apple for instance such footage will look not as contrasty and nice because Apple computers use by default Gamma 1.8 which is not compliant to REC709. Apple has its own colour space, Apple Space :). If you switch gamma to 2.2 the Apple is back on track. Apple is going to change this in its next OS.

So don't confuse viewing device (colour space) with RedSpace (LUT). RedSpace applies a colour matrix to your footage, so does Red's REC709 (confusing naming), so does RedLog, so do all other LUTs.

Regarding RedCine: I'm no expert in Red's apps. So I cannot say what the camera settings mean. Camera RGB makes sense for me, all others I don't know.

The other menue applies a LUT to your footage. RedSpace looks contrasty and vibrant, RedLog is optimized for 10 bit files (remember that Red's sensor has 12 bit), REC709 is the oldest LUT if I remember correctly. Many user complained that it renders too dark pictures - hence the new RedSpace. If you switch that all off you look at the linear RGB - pretty dark not nice at all.

In a grading system you want that, because you can create with the tools the application is providing your own LUT - for instance LevanSpace (not a colour Space, again a confusing naming for a LUT). Grading means creating for every single shot a individual LUT - for a certain colour space / viewing device, eg. REC709.

Creating a LUT that masters in an appealing way most footage without losing too much information is a big task.

I'm no expert in these things. So asking Graeme Nattress as one of the developers would be the best, actually.

Hans
 
Hi Hans,

great answer, and very interesting, I really appreciate it. I feel like I am starting to understand it, but still a bit confused. so let me dig in some details if you don't mind:

1) so as I understood colorspace is kind of a viewing enviroment. technically, it could be affected with anything, from electronics to a how dark it is in the room or if sun is hitting the monitor. but of course we want to have some standards, we can not consider every sunray hitting the monitor or a projectors, so we have some standard colorspaces. like rec709.... oooooh, I can not even state the question, it is very confusing. :) <--- I am not deleting it, because it kind of is a question in a way, but feel free to ignore it.

2) anyways, what confuses I guess is that in one case you talk about rec709 as a LUT, but then again you talk about it as a device in your lab SONY CRT. so confusion comes from this. now here is how I understand a LUT. it is kind of an algorithm, which tells certain pixel data how to change in order to look right on this particular device. this is kind of clear. so RED record some electronic impulses, which turn into a data, now when you apply REC709 as a LUT it looks in a certain way, but when you view it on apple cinema display it is different from when you look at it on sony CRT, so what is the deal here? so this is why I am confused why rec709 or redspace is LUT.

3) no on the other hand I assumed LUT was on to make something look right, but it does not actually change any pixel data, and when you render it out, it is rendered without considering LUT change. which is not the same with rec709 or redspace either in redcine or color REDROOM.

so I guess I will have more questions, but only after a will clarify this, I just do not want to confuse myself.
 
Hi Levan,

To 1. Colour space is the setup of your monitor, screen what ever you look at. Apple's gamma 1.8 makes pictures more flat than the standard gamma 2.2 you find on most computer screens. Colour space Rec709 is close to this. And yes, it does matter how the viewing environment looks like. Grading in an orange painted room will make you grading more blueish pictures than you would have graded in a neutral, grey environment. Although your HD monitor might be calibrated carfully to the specs of REC709 the orange walls in your grading suite will influence the result visibly .

To 2. Red's naming is confusing. The Rec709 setting in RedCine is a LUT. It is named after the colour space it is meant for: Rec709. Same with RedSpace. Another LUT and no colour space. Again confusing. Sorry for that.

To 3. A LUT is a Look Up Table. Basically a colour matrix. It only makes sense if applied to its specs. If you use a Cinespace LUT for grading in a REC709 environment (colour space) it might give you funky results you like but it is not meant for those usage. Red's Rec709 LUT in contrast is made to deliver a meaninful result when looking at Red footage in a REC709 environment (colour space). Reds RedSpace is a more vibrant looking derivate of Red's Rec709 LUT.

You can use a LUT just for viewing purposes, eg. translating one colour space to another (this is Apple doing with its tedious gamma 1.8 to 2.2 translation within FCP) or Rec709 to film. Or you can use a LUT and apply it directly onto the footage and when you render it out you have it baked in, meaning the pixel have changed to the LUTs specs. That is happening when you select RedSpace or Red's Rec709 in RedCine.

There are very andvanced techiques which are currently just envolving: A LUT does not neccesarily need to be baked in but also can be stored in the metadata and displayed by the GPU. With such footage the look can be changed within seconds withput touching the actual pixel of the file. This is called non-distructive grading. Advanced grading systems take already advantage of these techniques.

Hans
 
Dustin Cross said:
Aloha,

What Gamma and Color Space should I use in Apple Color for grading R3D files? When I work in Redcine I normally use Redspace and Redspace, but in Color I have access to my HD CRT studio monitor which is 709 HD color space.

What settings should I use in Apple Color?

Most likely we will be outputting to HDCAM SR tape in 1080p.
Click to expand...

It largely depends on whether you are a trained colorist and want to make things look as good as possible, or you are not, and want a "quick fix" to get you in an acceptable range without a lot of work on your part.

The LUTs provided are the same as the ones included with Red's own programs, and give you reasonable starting points for achieving an image that resembles fairly closely what the scene looked like when you shot it. That color spaces are matrixes that combine the three color primaries in ways that represent the bias of the sensor relevant to particular display standards. In other words, they get the saturation back to "normal" by compensating for the fact that some information for each of the three color components is contained in the other two because color filters and sensor biases are not pure. Percentages of all three are combined for each, and the result yields a saturation level that is more natural. These are tailored for the particular color system involved, i.e., Rec709 (HD Video), Redspace (a "corrected" version without a particular display/recording system involved), and Camera RGB (basic correction based on characteristics of the sensor only). The gamma LUT's are curves that are applied to make the image look correct on electronic displays, since no current displays are truly linear (your eyes aren't, either).

Your question as to what to use is not as simple as you probably think it is, because there are characteristics of Red's images that are not immediately obvious. If you are not really a colorist, and just want to do a bit of tweaking to something that's relatively accurate to the original photography, the most appropriate combination is probably Redspace color space and Redspace gamma. This will give you a basic correction for a video display that is relatively close to what was photographed. If you are a colorist, and are able to properly use the lift, gain, gamma, and balance controls in an efficient way, I've found that one of the best approaches is to use Redspace color space, but Redlog gamma. This is basically what a number of professional facilities do, and the advantage is that in addition to retaining all pertinent information, the image is mapped to the upper regions of the available digital levels. This means that to achieve a proper image, the information must be offset back down to the lower/middle of the histogram. This gets you proper brightness and contrast, but what it also does is lower the noise that is inherent in the lower regions even further, since you are almost never lifting the signal from its base levels. The results that I've gotten seem to indicate that using Redlog as your base yields the lowest noise final images by far of all the available approaches, without restricting the color choices, and without really requiring a log to lin LUT (since the log curve used is rather gentle, much like Panavision's Panalog). It may not be immediately obvious, but because of the particular characteristics of Red generated images, the use of Redlog tends to maximize the "good stuff" (i.e., color, detail, range, etc.) and minimize the "bad stuff" (i.e., noise). However, getting to a good starting point with this technique generally takes some skill and experience, so it's best used by those with a bit of a colorist background.

That's my take on it, anyway.
 
Hi
Just scrolled through the answers, and it was indeed helpful and well explained.
Thank you Hans!

Are
 
Michael, I fully agree concerning RedLog. From the very beginning I liked it most for grading. It's a good starting point. In build15 times Rec709 crushed the whites a bit. People with a hot spot on their forhead got bad holes. Not so with RedLog. I don't know how things changed in Build 16 in this regard but I guess Red put all their LUTs to a test.

Nevertheless, grading off the RAW data is even better. All are waiting for the announced RAW SDK.

Regards,

Hans
 
On a macbook pro to achive most acurate viewing (close to rec 709)
Shoud i corect it to 2.2 in the apple calibation tool
(Control panel display calibrate"expert")

will it cause any conflict with final cut
 
tell me if I am getting too picky and annoying with my questions, but hope this helps everyone :)

so here is what I concluded, tell me if I am wrong. in redcine and in color we have 2 popups for colorspace and gamma. colorspace is enviroment we are viewing the picture. and we see under the popup are LUTs. LUTs on the other hand are adjustment matrixs that consider differencies between system, in our case camera sensor is RGB which records linear light data in RAW, and if we choose cameraRGB as a LUT (for now I am just ignoring the gamma popup menu, lets assume there is nothing there) we will see what sensor recorded, and on my monitor (my colorspace) it will look or not look right, but it will be exactly what camera recorded, so it would be like no LUT is applied. now if I am viewing it on monitor which is HD, assuming that this monitor is in ideal and right enviroment (colorspace) with no orange walls, it means that my monitor is in rec709 colorspace. so, if I choose rec709 LUT, and this LUT was created by red (am I right here?) with one goal in mind to make sensor data (cameraRGB) look right/nice on rec709 enviroment/colorspace. after a year of development, with build 16 red came up with another LUT called redspace, which was also aimed to make sensor data look right on rec709 enviroment/colorspace, but made major adjustments to it, and improved the look we get when viewing it. this would cover the colorspace part. now here is one question, theoratically, if there was a way I could ask red to go to my editing suite which is with orange walls (it is not, just theoretically) and if red was a good friend of mine, I could ask them to design another LUT, which could take into consideration my orange walls, and this LUT would take sensor data and make it look best in my room, then call it levan'sORANGEspace and it would be somethin I would always start with, but since RED do not care about my room, and everybody elses rooms, they created for rec709, which is a standard space on average for everybody, is this right? and how should I have my room setup to be the ideal rec709 enviroment?

ok now to the gamma pupup, in this case cituation is similar, lets assume right now that we ignore colorspace pupup, it does not exist. so story would be following, camera natively is linear light, this is what sensor sees, and in this pupup menue we have linear, rec709, redspace, redlog, pdlog 685 all of this are LUTs, so if I apply linear LUT it means like not applying at all. well now if I want to preview it how it would look on film I would take pdlog, because film has different gamma, meaning that film is not sensetive to light in a linear way, right? so up to this moment it makes sense, but why again rec709 and redspace, I assumed they where LUTs to compensate the colorspace not the gamma, so now again lets return the colorspace pupup, if I already have rec709 selected there I have already compensated colorspace of the camera, oooo, or maybe it is that not only colorspace of the camera is different from HD monitor but gamma curve as well. any clarifications would help, I feel like I start to understand, but this little something is destructing.

now if my assumptions above were correct, selecting cameraRGB and linear light LUTs would mean that it is same as not having anything applied and looking at what sensor captured, kind of RAW data first hand. is it correct?

now one more confusion. about apple gamma. so as I know normal HD monitors are 2.2 and apple has 1.8, is it apple overall or is it FCP. so, if I have 2 cinema displays hooked up to my mac, and run color, one side preview and another user interface. so now looking at preview with rec709 is not right, since this monitor is 1.8 and not rec709. but if I have same cinema display connected via HD link or I have HD monitor, and they are connected with blackmagic or aja card, then I am viewing in rec709 colorspace is that right? but if I do not have HD monitor is there a way to override apple's (or is it FCP's) preset of 1.8 gamma and make it 2.2 real rec709?

and to make it more complicated, what if my final is SD, for television, how close ideal rec709 enviroment is to SD, as I know rec709 is HD standard, what should I do for SD?
 
B. Digital said:
On a macbook pro to achive most acurate viewing (close to rec 709)
Shoud i corect it to 2.2 in the apple calibation tool
(Control panel display calibrate"expert")

will it cause any conflict with final cut
Click to expand...

Yes, change to gamma 2.2. Applications such as Shake and I gues CS3/4 as well need gamma 2.2. Otherwise you are working in "Apple Space" which is not compliant to the normal video world (rec709, 601, computer gamma 2.2.)
FCP has an inbuild LUT that corrects the picture to look on a Apple 1.8 gamma screen like on a 2.2 gamma device.

AFAIK, FCP is not touched. The tedious gamma shift in QT remains. Sorry.

Hans
 
So if you are only a fcp guy leve gamma to 1.8 or if you desactivate the gamma corection in Quick Time pref. will it afect FCP

And...
In a perfect world shoud we talk more about of a gamma of 2.4 insted of 2.2
 
Levan Bakhia said:
tell me if I am getting too picky and annoying with my questions, but hope this helps everyone :)

so here is what I concluded, tell me if I am wrong. in redcine and in color we have 2 popups for colorspace and gamma. colorspace is enviroment we are viewing the picture. and we see under the popup are LUTs. LUTs on the other hand are adjustment matrixs that consider differencies between system, in our case camera sensor is RGB which records linear light data in RAW, and if we choose cameraRGB as a LUT (for now I am just ignoring the gamma popup menu, lets assume there is nothing there) we will see what sensor recorded, and on my monitor (my colorspace) it will look or not look right, but it will be exactly what camera recorded, so it would be like no LUT is applied. now if I am viewing it on monitor which is HD, assuming that this monitor is in ideal and right enviroment (colorspace) with no orange walls, it means that my monitor is in rec709 colorspace. so, if I choose rec709 LUT, and this LUT was created by red (am I right here?) with one goal in mind to make sensor data (cameraRGB) look right/nice on rec709 enviroment/colorspace. after a year of development, with build 16 red came up with another LUT called redspace, which was also aimed to make sensor data look right on rec709 enviroment/colorspace, but made major adjustments to it, and improved the look we get when viewing it. this would cover the colorspace part. now here is one question, theoratically, if there was a way I could ask red to go to my editing suite which is with orange walls (it is not, just theoretically) and if red was a good friend of mine, I could ask them to design another LUT, which could take into consideration my orange walls, and this LUT would take sensor data and make it look best in my room, then call it levan'sORANGEspace and it would be somethin I would always start with, but since RED do not care about my room, and everybody elses rooms, they created for rec709, which is a standard space on average for everybody, is this right? and how should I have my room setup to be the ideal rec709 enviroment?
Click to expand...

Hi Levan I like your post! Funny to read and yes, you got it right.

Levan Bakhia said:
ok now to the gamma pupup, in this case cituation is similar, lets assume right now that we ignore colorspace pupup, it does not exist. so story would be following, camera natively is linear light, this is what sensor sees, and in this pupup menue we have linear, rec709, redspace, redlog, pdlog 685 all of this are LUTs, so if I apply linear LUT it means like not applying at all. well now if I want to preview it how it would look on film I would take pdlog, because film has different gamma, meaning that film is not sensetive to light in a linear way, right? so up to this moment it makes sense, but why again rec709 and redspace, I assumed they where LUTs to compensate the colorspace not the gamma, so now again lets return the colorspace pupup, if I already have rec709 selected there I have already compensated colorspace of the camera, oooo, or maybe it is that not only colorspace of the camera is different from HD monitor but gamma curve as well. any clarifications would help, I feel like I start to understand, but this little something is destructing.
Click to expand...


PDL log does not show you how it would look on film if you would print the linear Red footage. For this there are LUTs like Cinespace or Truelight available, the latter from Filmlight. Those LUTs belong to advanced systems which are meant to build a colour pipleline which makes it possible to work in a "film-print-cinema-colour-space". If you need detailed information about this particular pipeline please contac Michael Most. He is a very valuable contributor in this forum and got deep knowledge (not only) in this regard (see his post above).

PDLog is a LUT that lets look red footage - after some tweaking with the exposure - like 35mm scans with Cineon LUT (hopfully got that right...). It's reasonable for those colorist who are used to grade with such footage. I have no experience in this regard so I'm not going further here.


Levan Bakhia said:
now if my assumptions above were correct, selecting cameraRGB and linear light LUTs would mean that it is same as not having anything applied and looking at what sensor captured, kind of RAW data first hand. is it correct?
Click to expand...

Yes.


Levan Bakhia said:
now one more confusion. about apple gamma. so as I know normal HD monitors are 2.2 and apple has 1.8, is it apple overall or is it FCP. so, if I have 2 cinema displays hooked up to my mac, and run color, one side preview and another user interface. so now looking at preview with rec709 is not right, since this monitor is 1.8 and not rec709. but if I have same cinema display connected via HD link or I have HD monitor, and they are connected with blackmagic or aja card, then I am viewing in rec709 colorspace is that right? but if I do not have HD monitor is there a way to override apple's (or is it FCP's) preset of 1.8 gamma and make it 2.2 real rec709?
Click to expand...

Set your graphic card to gamma 2.2 and you are fine. Gamma 2.2 and Rec709 are very close as you will see. Colorists, however, prefer a rec709 calibrated HD-SDI monitor. That has many reasons. 1. HD_SDI is 10 Bit whereas DVI is currently still 8 Bit. Professional scopes are the colorists best friends. They need SDI. You can dump footage via HD-SDI to HDCAM-SR or you can connect with a downconverter SDI CRTs which are still widely used. SDI is for video the golden standard.

Levan Bakhia said:
and to make it more complicated, what if my final is SD, for television, how close ideal rec709 enviroment is to SD, as I know rec709 is HD standard, what should I do for SD?
Click to expand...

No problem. Rec709 (HD) and ITU601 (PAL SDI) are very close, at least that's what I eyball. Both are video colour spaces in contrast to film-out.

Hans
 
B. Digital said:
So if you are only a fcp guy leve gamma to 1.8 or if you desactivate the gamma corection in Quick Time pref. will it afect FCP
Click to expand...

For convenience I would rather change the gamma of the graphic card to 2.2. Apple's 1.8 Gamma has it's roots in the print industry 20 years ago. There is no meaningful reason to work with video on a 1.8 gamma screen.

B. Digital said:
And...
In a perfect world shoud we talk more about of a gamma of 2.4 insted of 2.2
Click to expand...

Please elaborate.

Hans
 
I, sorry to pop in in the middle like this, but:

If you are trying to gradin in RedCine and do the final Grade in that program. Then it realy doesn't matter what you set the gamma/Space to. Since all you grading will be done to make it look good.
Although you will probably find it easier to reach the wanted grade if you start with a specific gamma/space. And the more you get used to grade in a specific gamma/space you will get better to grade from that. So even if you chose to start grading from a LinearLight/CameraRGB and get used to that "staring point" then that will be the best way for you to do it.
What you see is what you (kind of) get.

If you use RedCine to export DPX's to grade in a propper colorcorection (like Resolve, Luster etc etc) then you will probably want to export it as RedLog/RedSpace.
To export the stuff af Colorspace CameraRGB will (I think) not be ideal. Since this is showing exactly how the camera captured (thinks) that red/green/blue should look like. And this is without any interaction between the colors (a little bed in the blue, a little green in the red etc etc)
And since ALL cameras need this matrix done to the colors I think it's best to do the prior to export.
You can leave it for the colorist to deside how green the green should be, but he will end up with a bunch of secendary vectors/keys to make it look normal.
(bare in mind that a specific look might be easier to achive with the "wrong" colorspace to begin with)

To export it as Linear would recquier an 12bit file since the captured data is 12bit from the sencor. I gues a 16bit tiff would be ok and theoreticly that should be the best way to go from RAW to RGB. bit per bit, step per step.
I haven't tryed that.
I prefer to have the image come in to my grade as a flat image (although not too flat) so I can set the blacks down and lift up the whites to wher I want them.

I did a test with RedLog and RedSpace (gamma) and it felt better to use RedLog with the gamma lifted so I could put it down (and push the noice down tarward the blacks) rather then having a "more normal, maybe slightly to dark" gamma to start with. But feel free to do some tests.

I do belive that diferent graing tools work better/diferent with difrent gamma.
But the ColorSpace should be the same for all. since that is more about what color the colors should like like, And they should look "right".


If you use Color to grade, then you can consider the RedRoom to be the "developer" of the file. (or the scanner). From the setting in there is how you will start to grade it from when using the normal grade-tools in Color.
If you do a simple test with one RedLog and one Rec709 and try to match them to each other you will see it possible and kind of easy.


Rec709 is the HD standard and the SD one (at least 625/pal) is called Rec601. And they are diferent, but it doesn't matter cus they are Very close. If you monitor on a Sony BVM (CRT) in HD and switch to SD you wount see the diference in colorspace.

Hope this gave some answers rather then planting seeds for new Q's...

/carl
 
You must log in or register to reply here.
Back
Top