Display bit-depth?

[AstroBenny]

I've naughtily posted this again after realizing it's probably better suited to the people in this section of the forum.

Maybe you can forgive me as I'm approaching my 1000th post

I'm using a screen recorder and was wondering what the difference is between 0-255 and 16-235.

By default it suggests 0-255. When would I want 16-235?

Am I right in thinking that 0-255 is full Adobe RGB while 16-235 is Adobe sRGB?

[Enderman]

16-235 is just limited on the black and white end, idk why you would ever want that, unless for some reason your display cant do full RGB or something

[AstroBenny]

1 minute ago, Enderman said:

16-235 is just limited on the black and white end, idk why you would ever want that, unless for some reason your display cant do full RGB or something

I swear most monitors only support sRGB..

[Enderman]

2 minutes ago, AstroBenny said:

I swear most monitors only support sRGB..

test it yourself, see if you can tell the difference

i definitely can, both on my main TV and my laptop

 

[ALwin]

This has nothing to do with display bit depth.

[Glenwing]

Limited RGB is basically a legacy thing that was a standard used by video content, and still is used for most content, it's one of those "we still use it because we still use it" scenarios, TVs and even PC video players like VLC will automatically assume content is limited RGB, and no one wants to produce content that will look weird when played on the majority of devices. You can record games with OBS with full RGB recording enabled, play it back on VLC or windows media player, and there will be some pretty severe black crush. But it looks normal when imported into Adobe. Meanwhile if you record in limited RGB, it will look washed out once exported with Adobe.

[AstroBenny]

11 hours ago, Enderman said:

test it yourself, see if you can tell the difference

i definitely can, both on my main TV and my laptop

 

Yes I can. So the idea is that if this was being displayed in Limited RGB you wouldn't be able to tell the difference between the whites and blacks..?

[AstroBenny]

7 hours ago, Glenwing said:

Limited RGB is basically a legacy thing that was a standard used by video content, and still is used for most content, it's one of those "we still use it because we still use it" scenarios, TVs and even PC video players like VLC will automatically assume content is limited RGB, and no one wants to produce content that will look weird when played on the majority of devices. You can record games with OBS with full RGB recording enabled, play it back on VLC or windows media player, and there will be some pretty severe black crush. But it looks normal when imported into Adobe. Meanwhile if you record in limited RGB, it will look washed out once exported with Adobe.

But what is responsible for whether you see full RGB or Limited RGB?

The hardware you're using, the content you're watching, or the display you're using?

And what's the  difference between full RGB/Limited RGB compared to Adobe RGB?

[Glenwing]

13 minutes ago, AstroBenny said:

But what is responsible for whether you see full RGB or Limited RGB?

The hardware you're using, the content you're watching, or the display you're using?

And what's the  difference between full RGB/Limited RGB compared to Adobe RGB?

Well, ultimately everything is converted to full RGB for viewing on the display. But the actual video file may or may not be encoded as limited RGB for distribution, where the intensity of each individual color (red green and blue) only goes from values of 16-235 instead of 0-255, meaning the darkest shades and the lightest shades of each color are not available, and this leads to washed out blacks and less saturated colors. When playing back a video file, most software will assume all video files are encoded as limited RGB, and when decoding the file it will extend all colors back to full RGB. But if the file was already in full RGB, then extending it will crush blacks and oversaturate colors, because it's extending the colors to a greater intensity than normal to compensate for something that is not actually there, and it ends up overcompensating instead.

 

AdobeRGB is a color space, which is something different, don't lump them together just because the names are similar  RGB is the basic color set used to create all colors, so there are lots of things that have the term "RGB" in them, and they're not all directly related to each other. A color space, like AdobeRGB or sRGB, defines exactly what color intensities the values 0-255 actually represent. AdobeRGB's most intense red (intensity level 255) for example, is "redder" than red 255 in sRGB, which defines red 255 as a less intense shade of red. If you move an image originally designed for sRGB and open it in an AdobeRGB environment without color-managed software, all the colors will be off, because the RGB values in sRGB do not represent the same color as they do in AdobeRGB (again, red 255 in AdobeRGB is "redder" than red 255 in sRGB). You would need color-managed software like Photoshop, which can properly convert images between color spaces to avoid oversaturation.

[AstroBenny]

9 minutes ago, Glenwing said:

Well, ultimately everything is converted to full RGB for viewing on the display. But the actual video file may or may not be encoded as limited RGB for distribution, where the intensity of each individual color (red green and blue) only goes from values of 16-235 instead of 0-255, meaning the darkest shades and the lightest shades of each color are not available, and this leads to washed out blacks and less saturated colors. When playing back a video file, most software will assume all video files are encoded as limited RGB, and when decoding the file it will extend all colors back to full RGB. But if the file was already in full RGB, then extending it will crush blacks and oversaturate colors, because it's extending the colors to a greater intensity than normal to compensate for something that is not actually there, and it ends up overcompensating instead.

 

AdobeRGB is a color space, which is something different, don't lump them together just because the names are similar  RGB is the basic color set used to create all colors, so there are lots of things that have the term "RGB" in them, and they're not all directly related to each other. A color space, like AdobeRGB or sRGB, defines exactly what color intensities the values 0-255 actually represent. AdobeRGB's most intense red (intensity level 255) for example, is "redder" than red 255 in sRGB, which defines red 255 as a less intense shade of red. If you move an image originally designed for sRGB and open it in an AdobeRGB environment without color-managed software, all the colors will be off, because the RGB values in sRGB do not represent the same color as they do in AdobeRGB (again, red 255 in AdobeRGB is "redder" than red 255 in sRGB). You would need color-managed software like Photoshop, which can properly convert images between color spaces to avoid oversaturation.

So all displays regardless of being a TV or monitor can display full RGB but it happens to be that TV/movie content is 16-235 while games/pc content is 0-255?

If programs like VLC are on the PC, why wouldn't they just adopt the 16-255 full RGB?

Are internet programs like Youtube using limited or full RGB?

[Glenwing]

11 minutes ago, AstroBenny said:

So all displays regardless of being a TV or monitor can display full RGB but it happens to be that TV/movie content is 16-235 while games/pc content is 0-255?

If programs like VLC are on the PC, why wouldn't they just adopt the 16-255 full RGB?

Are internet programs like Youtube using limited or full RGB?

Yes, and games are rendered in real time so they are in full RGB, but almost all video files are in limited RGB regardless of whether they are played on TV or PC, the display will extend them to full RGB. A lot of TVs convert the content from limited to full RGB themselves, while monitors generally don't, and it's the job of the video player or display driver to convert before sending.

 

I don't know about YouTube.

[AstroBenny]

2 minutes ago, Glenwing said:

Yes, and games are rendered in real time so they are in full RGB, but almost all video files are in limited RGB regardless of whether they are played on TV or PC, the display will extend them to full RGB. A lot of TVs convert the content from limited to full RGB themselves, while monitors generally don't, and it's the job of the video player or display driver to convert before sending.

 

I don't know about YouTube.

So back on topic..

Am I correct in thinking that you would use 16-235 in the recording software when recording films/movies because that is what they are created in?

[Glenwing]

1 hour ago, AstroBenny said:

So back on topic..

Am I correct in thinking that you would use 16-235 in the recording software when recording films/movies because that is what they are created in?

I'm not a film expert, but I think it is only something applied after, when it's exported to file for distribution, not in the original recordings.

[Enderman]

6 hours ago, AstroBenny said:

Yes I can. So the idea is that if this was being displayed in Limited RGB you wouldn't be able to tell the difference between the whites and blacks..?

tru

[AstroBenny]

9 hours ago, Glenwing said:

 

 

AdobeRGB is a color space, which is something different, don't lump them together just because the names are similar  RGB is the basic color set used to create all colors, so there are lots of things that have the term "RGB" in them, and they're not all directly related to each other. A color space, like AdobeRGB or sRGB, defines exactly what color intensities the values 0-255 actually represent. AdobeRGB's most intense red (intensity level 255) for example, is "redder" than red 255 in sRGB, which defines red 255 as a less intense shade of red. If you move an image originally designed for sRGB and open it in an AdobeRGB environment without color-managed software, all the colors will be off, because the RGB values in sRGB do not represent the same color as they do in AdobeRGB (again, red 255 in AdobeRGB is "redder" than red 255 in sRGB). You would need color-managed software like Photoshop, which can properly convert images between color spaces to avoid oversaturation.

When you say Adobe RGB's red is "redder" than Adobe sRGB's most intense red, what does this actually mean? lighter?

And if they have the same bit depth for both colour spaces, why would the 256 shades of red for the Adobe RGB be more accurate than the 256 shades available in Adobe sRGB?

[Glenwing]

2 hours ago, AstroBenny said:

When you say Adobe RGB's red is "redder" than Adobe sRGB's most intense red, what does this actually mean? lighter?

And if they have the same bit depth for both colour spaces, why would the 256 shades of red for the Adobe RGB be more accurate than the 256 shades available in Adobe sRGB?

If you could see them side by side you would know it's difficult to explain without visual aide.

 

It's not more accurate, it just includes a larger range of colors. If you have the same number of shades, spread among a larger gamut of colors, then the shades will be more spread out, and won't stand for exactly the same colors. Like if you had a small bucket and a large bucket of water, 1/10th full, 6/10ths full, etc. mean different amounts of water depending on which bucket you are using.

[AstroBenny]

1 hour ago, Glenwing said:

If you could see them side by side you would know it's difficult to explain without visual aide.

 

It's not more accurate, it just includes a larger range of colors. If you have the same number of shades, spread among a larger gamut of colors, then the shades will be more spread out, and won't stand for exactly the same colors. Like if you had a small bucket and a large bucket of water, 1/10th full, 6/10ths full, etc. mean different amounts of water depending on which bucket you are using.

Ah-I see!

 

But for the intensity, are you referring to the value of 0-255?

For example, is a 200 value more "intense" than a 100 value?

[Glenwing]

2 hours ago, AstroBenny said:

Ah-I see!

 

But for the intensity, are you referring to the value of 0-255?

For example, is a 200 value more "intense" than a 100 value?

Yes

[AstroBenny]

On 4/1/2016 at 8:05 AM, Glenwing said:

Well, ultimately everything is converted to full RGB for viewing on the display. But the actual video file may or may not be encoded as limited RGB for distribution, where the intensity of each individual color (red green and blue) only goes from values of 16-235 instead of 0-255, meaning the darkest shades and the lightest shades of each color are not available, and this leads to washed out blacks and less saturated colors. When playing back a video file, most software will assume all video files are encoded as limited RGB, and when decoding the file it will extend all colors back to full RGB. But if the file was already in full RGB, then extending it will crush blacks and oversaturate colors, because it's extending the colors to a greater intensity than normal to compensate for something that is not actually there, and it ends up overcompensating instead.

 

AdobeRGB is a color space, which is something different, don't lump them together just because the names are similar  RGB is the basic color set used to create all colors, so there are lots of things that have the term "RGB" in them, and they're not all directly related to each other. A color space, like AdobeRGB or sRGB, defines exactly what color intensities the values 0-255 actually represent. AdobeRGB's most intense red (intensity level 255) for example, is "redder" than red 255 in sRGB, which defines red 255 as a less intense shade of red. If you move an image originally designed for sRGB and open it in an AdobeRGB environment without color-managed software, all the colors will be off, because the RGB values in sRGB do not represent the same color as they do in AdobeRGB (again, red 255 in AdobeRGB is "redder" than red 255 in sRGB). You would need color-managed software like Photoshop, which can properly convert images between color spaces to avoid oversaturation.

So TV's display in full RGB even if you have them set to 16-235?

Is that because if the input range is set to 16-235 it allows the TV to convert the content correctly to full RGB?

[Glenwing]

5 hours ago, AstroBenny said:

So TV's display in full RGB even if you have them set to 16-235?

Is that because if the input range is set to 16-235 it allows the TV to convert the content correctly to full RGB?

As I understand it, yes, whereas if it's set to full RGB it will assume the content is already in full RGB and will not try to convert it. I'm not really a TV guy though, so I'm not 100% on the details.

[AstroBenny]

11 hours ago, Glenwing said:

As I understand it, yes, whereas if it's set to full RGB it will assume the content is already in full RGB and will not try to convert it. I'm not really a TV guy though, so I'm not 100% on the details.

I'm going slightly off topic here but who better to ask than you

If a monitor says it supports 100% sRGB does that mean it has to be in the sRGB mode on the display to see 100% sRGB?

If I was in standard mode for example, would I still get 100% sRGB? Or once you leave sRGB, am I using a different colour space?

Is the sRGB mode just calibrated in a way to depict the most uniformity with the sRGB colour space?

[AstroBenny]

On 4/3/2016 at 8:56 PM, Glenwing said:

As I understand it, yes, whereas if it's set to full RGB it will assume the content is already in full RGB and will not try to convert it. I'm not really a TV guy though, so I'm not 100% on the details.

Also, since most computer content is in the sRGB colour space, why in the Nvidia control panel can you only use "RGB" and not sRGB?

[Glenwing]

On 4/4/2016 at 11:53 PM, AstroBenny said:

I'm going slightly off topic here but who better to ask than you

If a monitor says it supports 100% sRGB does that mean it has to be in the sRGB mode on the display to see 100% sRGB?

If I was in standard mode for example, would I still get 100% sRGB? Or once you leave sRGB, am I using a different colour space?

Is the sRGB mode just calibrated in a way to depict the most uniformity with the sRGB colour space?

It's not guaranteed to be 100% sRGB if you don't run in sRGB mode. On the same token, if you have a monitor which is capable of reproducing 100% of the AdobeRGB color space, which includes colors outside the sRGB space, then setting the monitor to sRGB mode will limit it to only use colors within the sRGB color space and not show those extra colors. 

On 4/4/2016 at 1:59 PM, AstroBenny said:

Also, since most computer content is in the sRGB colour space, why in the Nvidia control panel can you only use "RGB" and not sRGB?

That isn't a color space selector, that's for the overall color model, RGB, as opposed to YCbCr or some other color model.

[AstroBenny]

6 hours ago, Glenwing said:

It's not guaranteed to be 100% sRGB if you don't run in sRGB mode. On the same token, if you have a monitor which is capable of reproducing 100% of the AdobeRGB color space, which includes colors outside the sRGB space, then setting the monitor to sRGB mode will limit it to only use colors within the sRGB color space and not show those extra colors. 

That isn't a color space selector, that's for the overall color model, RGB, as opposed to YCbCr or some other color model.

So when using a monitor calibration kit, do you have to select the colour space you are trying to achieve? What does it use as a correct 'reference point' for what a certain colour should look like?

My monitors support 100% sRGB and have them calibrated using a guide from Tom's hardware. Is the aim of the calibration to properly display the colour space the monitor is capable of displaying?

[Glenwing]

1 hour ago, AstroBenny said:

So when using a monitor calibration kit, do you have to select the colour space you are trying to achieve? What does it use as a correct 'reference point' for what a certain colour should look like?

My monitors support 100% sRGB and have them calibrated using a guide from Tom's hardware. Is the aim of the calibration to properly display the colour space the monitor is capable of displaying?

Well ultimately the goal of calibration is to get multiple devices to look the same. Mostly it's only important for print media, so that images on the screen look exactly the way they will look when printed out on a printer which is also calibrated.

 

The corners of the color space (full red, full green, and full blue) are the reference points for a color space, since all other colors are combinations of those primary colors, the monitor's entire capability is dictated by what the monitor's most intense red green and blue are. Color space isn't just the boundary colors though, since you could have two color spaces with the same boundaries (same definitions of what color red 255, green 255, and blue 255 are) but different distribution of shades, so that red 160 for example is not the same on both color spaces.

 

There are 256 shades of each color (including off/black) on an 8-bit per channel monitor, numbered 0 through 255, with 255 being the most intense shade of that color. 254 is a slightly duller shade, 253 slightly duller, and so forth. But the 256 shades are not equally spaced, it's a non-linear distribution (because the sensitivity of the human eye to brightness changes is also non-linear), instead the darker shades are closer together, and as you get brighter, the shades get further apart. The exact distribution of shades is determined by a function known as the gamma function. Each color space specifies a gamma number which is used in the formula to set the steepness of the curve, and all 256 shades are set accordingly. A monitor needs to use the same boundary colors as a certain color space and follow the gamma curve defined by that color space to ensure that every possible color is accurate, not just the boundaries, but all the inbetween colors as well.