Jeremy Dulac

Simulating Film Halation

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I was wondering if anyone has any tips on simulating film halation, i.e. the red fringing around high contrast edges - I find it to be a very pleasing effect. I understand how to create highlight blooming, which is sort of what people think of when you say halation - but the effect (which seems it is probably a bit trickier to create) of red fringing around edges is really what I am after. I have attached an image for reference. Any pointers or tips would be super appreciated!

Cheers!
Jeremy

gallery12_01_1920x1080.jpg

gallery12_02_1920x1080.jpg

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Hi Jeremy

here's my 2 cents

you could try with an edge detect fed as a mask into a node and slightly color it (in resolve)

in nuke you can use a lightwrap node with a very tight diffuse

 

Orash

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@Orash Rahnema Thanks for the reply! I saw the edge detect ofx in resolve, but could'nt figure out exactly how it works as a mask...ive seen others talk about using it that way. Would you mind explaining the node structure to make it work as a mask? 

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Use the Edge Detect plugin to generate a mask, and apply it to a node where you blur just the red channel. Blurring edges reduces contrast, causing the brighter outside edge to darken and the darker inside edge to lighten. Applying a max operation to the original image and the adjusted version will preserve the original pixels that were darkened by the process, while keeping the newly brightened pixels. This has the effect of something similar to a light-wrap, though in this case it's just the red channel that leaks. The max operation can be performed in an number of different ways in Resolve, and one such way is to use a layer node with the blending mode set to lighten.

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Man this is super helpful - I just tried these techniques and they have gotten the effect I want almost perfectly. Thanks a ton for the help!

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By the way - how do you create highlight blooming? I tried different blur setups but haven't been satisfied yet.

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The way I do it is to key the highlight, add a ton of blur to the key, then lift both gamma and lift while lowering the gain to control. 

If needed add a bit of colour to the lift control. 

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Hi! I stumbled on this forum and I have a quick question regarding edge detect. How do I make it a mask? I'm still quite new to Resolve so some of these things go right over my head haha. Thanks!

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I would point to the Oscar-winning film The Artist as an example where they not only digitally created "halation," but they went a step further and made modern 35mm color film look like 1920s B&W nitrate film. That's a very clever trick, and I think it helped sell the look and period of the film very well. Only Richard Deusy as Duboircolor in France knows exactly how they did it, but I think you can bet there were carefully-qualified keys, a glow filter of some kind, and some blur here and there. Great lighting and filtration in-camera probably helped as well. It's a great-looking film -- all shot on film, but (ironically) done at Red Studios on Cahuenga Blvd. in Hollywood. 

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3 hours ago, Marc Wielage said:

but they went a step further and made modern 35mm color film look like 1920s B&W nitrate film.

Were they putting anti-halation backing layers in nitrate film of the 1920's?

Tried researching this on the internet, but haven't found any info about when these backing layers were introduced.

Interesting other info I discovered whilst searching - is that there's a type of halation called Light Piping, especially with polyester-based film. According to Kodak information, it 'can transmit or pipe light that strikes the edge of the film and result in fog'. I guess this probably looks like edge fog but must be very image-dependent.

 

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You can edge detect without using a plug-in:

1. Pull a luma key (node/layer a) and copy it to node/layer b

2. Very slightly blur and erode the key in A

3. Very slightly blur and dilate the key in B

4. Do a matte operator (matte merge or layer blend) and do a diff ( or is it an Or or Union? I forget but you can find the right combo by experimenting)

5. Viola! Edge-detect. Experiment with the matte tool operators by tweaking the blur amounts - maybe no blur at all on step 2, or add blur to the resultant edge matte for another look.

The exact methodology will of course vary depending on the grading platform, but the concept is the same. 

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(edited)

Hi Orash Rahnema,

 

The edge-detect works. But it is detecting all the edges, do you know how would it be possible to make the edge detect working only for the highlights. I've tried using the secondaries on the ofx node, but it doesn't work, as well as different techniques. But no satisfying result.. because we got halation in the shadows too..  

 

Douglas Delaney, do you have any node tree to show us? I would be very interested 

 

Thanks guys,

 

Valentin Alt, ISP

Edited by Valentin Alt

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