Density

[lewis jacobs]

Would someone be able to explain to me how in colour grading you can create "density" in an image or give the image "weight"???

[Abby Bader]

Density is brightness (offset slider). 

[lewis jacobs]

28 minutes ago, Abby Bader said:

Density is brightness (offset slider). 

Is that all? I thought it might be something to do with compressing the colours 

[Keidrych wasley]

Density can be used as a term to describe the lowering of colour luminance which brings a perceptual richness to colours. If for example using Tetra you lower all three channels of red (red red, red green, red blue) you will get a perceptual ‘density’ to red as the luminance is lowered. There are tools that add saturation whilst lowering luminance to model a film style subtractive saturation which also brings a feeling of density to colour. 

[Bruno Mansi]

Going back to my still photography days, density was a term used to to describe the amount of silver (and hence the amount of dye in colour stock) in a negative. 

Underexposed negatives were called 'thin',  whilst adding one or two stops of light above the optimum exposure would produce a denser negative. Since film had a good exposure latitude, it wasn't uncommon to overexpose by a stop or two.  As long as you weren't blowing out highlights, this technique could capture more detail in the blacks and produce richer images due to the increase in silver/dye.

However, this wasn't without it's own problems as colour film could produce hue shifts when subjected to overexposure. Fujifilm, for example was known to lean towards magenta when overexposed.

As others have stated, this characteristic of film density is being translated to digital images as a way of mimicking the film look.

[lewis jacobs]

41 minutes ago, Bruno Mansi said:

Going back to my still photography days, density was a term used to to describe the amount of silver (and hence the amount of dye in colour stock) in a negative. 

Underexposed negatives were called 'thin',  whilst adding one or two stops of light above the optimum exposure would produce a denser negative. Since film had a good exposure latitude, it wasn't uncommon to overexpose by a stop or two.  As long as you weren't blowing out highlights, this technique could capture more detail in the blacks and produce richer images due to the increase in silver/dye.

However, this wasn't without it's own problems as colour film could produce hue shifts when subjected to overexposure. Fujifilm, for example was known to lean towards magenta when overexposed.

As others have stated, this characteristic of film density is being translated to digital images as a way of mimicking the film look.

Thanks for the detailed response 

[lewis jacobs]

11 hours ago, Keidrych wasley said:

Density can be used as a term to describe the lowering of colour luminance which brings a perceptual richness to colours. If for example using Tetra you lower all three channels of red (red red, red green, red blue) you will get a perceptual ‘density’ to red as the luminance is lowered. There are tools that add saturation whilst lowering luminance to model a film style subtractive saturation which also brings a feeling of density to colour. 

Sorry what do you mean by tetra?

[Keidrych wasley]

Tetra is a dcil tool floating about online if you google it. Very useful for shifting the position of primaries, changing their colour and luminance without effecting the greyscale and doing so quite cleanly.

[Nico Wieseneder]

Keidrych already explained it very well and mentioned a great tool you can explore. Another one would be the "Film Density" DCTL by Paul Dore: https://github.com/baldavenger/DCTLs/blob/master/DCTL_OFX/Film_Density_OFX_DR17.dctl 

[Adéyẹmi]

On 10/9/2021 at 11:13 AM, lewis jacobs said:

Would someone be able to explain to me how in colour grading you can create "density" in an image or give the image "weight"???

I think what u r trying to say is texture/rich contrast. A punchy looking image. Play with your luminance tools. Lift gamma gain. That's the best there is. Always lower your highlights. Keep them soft. Play with the mid tone to keep the image bulky, by lowering it too. You will start to see the difference. Keep a good reference. It's all in your lift gamma gain. Sat VS Lum is another good tool to play with. 

Edited October 17, 2021 by Adéyẹmi

[Keidrych wasley]

5 minutes ago, Adéyẹmi said:

I think what u r trying to say is texture/rich contrast. A punchy looking image. Play with your luminance tools. Lift gamma gain. That's the best there is. Always lower your highlights. Keep them soft. Play with the mid tone to keep the image bulky, by lowering it too. You will start to see the difference. Keep a good reference. It's all in your lift gamma gain. Sat VS Lum is another good tool to play with. 

Lift gamma gain makes 1D adjustments and is very simple and limited math.  Lift gamma gain will effect your tone curve and contrast. Tetra  / Paul Dore's Film Density will make 3D adjustments not possible with lift gamma gain. Tetra can make adjustments to color that are independent of contrast and do not effect contrast. So if you want to lower the perceptual density / luminance of specific colours to make them feel 'rich' without effecting your contrast, Tetra can be very powerful indeed. It's important to point out that 2 images with the same contrast can have very different feelings of color richness and color 'density' depending on how the colours are being effected, and to make those types of more complex adjustments requires tools capable of 3D color manipulation. Another tool for example would be Resolve Hue vs Lum curves.

[lewis jacobs]

Thanks for the detailed reply. I think you know what I mean when I say some images look really saturated and 3d and "thick" without looking over saturated  just looking like someone just raised the global saturation. I would love to learn more about specifically adjusting the hue/sat vs lum curves ect to achieve this this richness?

[Keidrych wasley]

1 hour ago, lewis jacobs said:

Thanks for the detailed reply. I think you know what I mean when I say some images look really saturated and 3d and "thick" without looking over saturated  just looking like someone just raised the global saturation. I would love to learn more about specifically adjusting the hue/sat vs lum curves ect to achieve this this richness?

The thing to bear in mind is when you increase saturation in a typical color corrector using the saturation knob what happens is you are effectively increasing the luminance of all the colours and pushing them all equally to the edge of your gamut. So the colours are becoming brighter and brighter and more garish and unnatural. Film on the other hand saturates differently - as saturation increases the luminance of colours decrease. Both the color corrector and film density saturation look saturated, but with a totally different perceptual feel. The color corrector saturation will make an image become more and more thin looking, the film density / subtractive saturation will become more and more ‘rich / thick’ and deep looking. Film will also shift hue along with reducing luminance eg deep low luminance reds might become more yellow instead of more bright and magenta etc. The way that film saturates is part of the reason it is still studied and modelled digitally. 

[Bruno Mansi]

You might want to take a look at the Look Development & Workflow course (Jason Bowdash) on Lowepost.

In lesson 13 (Complex Saturation Workflows) he uses LAB and HSL/HSV workflows to reproduce the sort of colour depth that's being discussed in this thread.

 

292xap87.75.54.224

 

[Yahya R Yax]

The easiest way is download a dctl which allow you to get the dencity of certain colours or chance the colourspace on node either HSL or HSV and play with the luminous section on the RGB bar.

[Kye Leslie]

How well does the Resolve Sat vs Lum curve compare in comparison to more sophisticated subtractive-colour tools?  It's very handy to use!

[Nico Wieseneder]

9 hours ago, Kye Leslie said:

How well does the Resolve Sat vs Lum curve compare in comparison to more sophisticated subtractive-colour tools?  It's very handy to use!

I'd suggest to use whatever fits your needs/workflows and gets the results you're after for a specific job. Some feel more comfortable with one tool while others totally prefer another one. Usually the difference for example between the Sat Vs Lum curve, the Color Warper (if you're adjusting luminance there) and some custom tools implemented via DCTLs is that they all are based on different math and/or color space under the hood.