Part 3: Avoiding the Icy Sea

OK, so maybe you don't like all this ICC color management stuff. Maybe you long for the simplicty of eLin.* Maybe you want parallel color pipelines in all your floating-point comping apps.

Remember this article? It described using the eLin color model in Shake, and this one talked about Fusion. Now you can use this same true floating-point implementation of the eLin color model in After Effects 7 as well. The Anim Presets below follow the same naming convetion as the Shake and Fusion Macros, and do exactly the same things. To work with them in AE7, leave color management off (set Project Working Space to None), and set up Guide Adjustment Layers (AKA LUT layers) to hold your lin2vid Presets, just like you did for eLin.

eLin_float.zip (17.1kB zip file UPDATED 2/11/06)

* No, I know you don't.

Comments

[payton]

hi stu,
great blog. i love it.
i think im missing a thing in understanding all this true linear stuff. im trying to recreate your elin tutorial "LAday" with AE7. im using your supported vid2lin and lin2vid .ffx presets. but can you tell me:
when im viewing an elin comp without a lut its really!! dark. but the same thing with a gamma correction only of 0.45 isnt nearly as dark. what´s causing this? whats missing?
would be great if you can answer to this. it´s driving me crazy ;)
bye,
payton

[Stu]

Payton, the vid2lin .ffx should be nothing more than a gamma of 0.4545, so it should look the same. Unless you're talking about the old eLin plug-ins for AE6.5, where indeed the linear images are super dark because they are underexposed to accomodate overbrights.

Does that help?

[payton]

thx for this immediate response! :)
let me try it again please.
im comparing these things:

1. image X imported into AE with effect (not preset!) vid2elin applied. without a lut it looks quite dark

2. same image X imported into AE with gamma correction of 0,45 applied. no lut layer too. this one looks much brighter

but i dont understand why. both should be in linear lightspace with no gamma correction and (as far as i know) look similar. what does the effect "vid2elin" more than a simple gamma-correction?

do you understand what i mean?

thanks again,
payton

[Stu]

Thanks for the more detailed explanation. The vid2eLin effect is both linearizing and underexposing the image to leave room for overbrights in a clamped, 16bpc buffer. This is only necesdsary in versions of AE prior to 7.0. If you're using AE7, then ditch the eLin plug-ins and use the presets in a 32bpc project. The preset doesn't need to underexpose the image, it just strips out the gamme. The result is an image that looks dark when viewed without correction, but not nearly as dark as the eLin image.

Better still, use a linear profile as your Project Working Space, thereby eliminating the need for LUT Layers altogether.

[payton]

thanks again for the answer and sharing your knowledge, presets ´n stuff here.

i worked with your presets, cause im familiar with this technique.

now i tested a linear working space project (thx for the profile!) and it works fine for me too.

thanks,
payton

[Peter Debay]

Dear Stu,

I appreciate your ongoing contribution to the vfx and after effects communities.

I have a question about your eLin-style presets - when would one use the eLin Cin set of presets over the eLin (non-Cin) presets? I notice in your image above that you are dragging the eLin log2lin onto a cineon file.

Thanks, Peter

[Stu]

Hi Peter,

Much has changed since these presets were created. At this point I would not make the same differentiation I made before between eLin and eLin cin. I would use the eLin presets for video sources and the eLin_cin presets for film sources, and then use a 3D LUT for the display correction.

[Peter Debay]

Thanks for the quick response Stu.

Are your presets on AE adjustment layers considered 3D LUT's or just viewing LUT's? Other than Proof Colors or Color Finesse's .cfpresets, I can't think of any other way to apply a 3D LUT in AE - any advice?

Thanks in advance

[Stu]

The color profiles described in this post are 3D LUT's.

[Peter Debay]

Thanks Stu, I'm beginning to understand these concepts and practices better!