Return-Path: Received: from mail-tul01m020-f169.google.com ([209.85.214.169] verified) by media-motion.tv (CommuniGate Pro SMTP 4.2.10) with ESMTP-TLS id 4615176 for AE-List@media-motion.tv; Fri, 03 Feb 2012 03:19:54 +0100 Received: by obbta7 with SMTP id ta7so3995363obb.28 for ; Thu, 02 Feb 2012 18:25:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :content-type; bh=heHA8WjXDzClu0H6NEx0DPSiVRnDw1VW7QgR36qdLeQ=; b=iwHH7KzIYkpyWIwRDfSR0etCzl3aKTsizLAgiebv/O67zVv5LAIvKn2ZWc4UdbGQaf W1qeHshVAApPv6Jd4XhDFmCdyCuvJX/WEWopfbRysBxT90Ce/oVSTNp8O6mMUaWCsAxe mmp0jMS9SPO3R4IxmoFwIltcUwnFA/7fyYlTU= Received: by 10.182.59.41 with SMTP id w9mr4829300obq.70.1328235945678; Thu, 02 Feb 2012 18:25:45 -0800 (PST) MIME-Version: 1.0 Received: by 10.182.48.200 with HTTP; Thu, 2 Feb 2012 18:25:25 -0800 (PST) In-Reply-To: References: From: Byron Nash Date: Thu, 2 Feb 2012 21:25:25 -0500 Message-ID: Subject: Re: [AE] Inverse a LUT? To: After Effects Mail List Content-Type: multipart/alternative; boundary=14dae93b5deab8571e04b80607a3 --14dae93b5deab8571e04b80607a3 Content-Type: text/plain; charset=ISO-8859-1 That's what I'm doing, and it works great until you have to put a piece of footage or a graphic in there that has a different color space. What we are trying to do is deliver a shot to color correction that does not have the LUT applied. On Thu, Feb 2, 2012 at 8:52 PM, Chris Biggs wrote: > I apply my LUTs to an Adjustment layer on top of my comp, then make it a > guild layer, as to not render out > no need to reverse then. > > > On Thu, Feb 2, 2012 at 12:51 PM, Byron Nash wrote: > >> It's a 3D LUT from the Arri site, LogC2Video_Rec709. >> >> >> >> On Thu, Feb 2, 2012 at 3:13 PM, Brendan Bolles wrote: >> >>> It depends on your LUT. If it's a 3D LUT, then it can not be inverted >>> in general. 1D LUTs can often be inverted. LUT Buddy has an invert button >>> that will be enabled when the LUT is invertible. >>> >>> In the 3D LUT case, imagine you had a LUT that was used to turn your >>> image black and white (desaturate). As you know, no color operation could >>> hope to magically restore the color once it had been taken out. So that's >>> a clue as to why 3D LUTs can't generally be inverted. >>> >>> If you created your 3D LUT using a series color corrections, your best >>> hope is to try to apply them in reverse with inverted settings. You could >>> then make a LUT of that operation to be your inverted LUT. >>> >>> But usually you just try to come up with something close or deal with it >>> on a case-by-case basis. >>> >>> >>> Brendan >>> >>> >>> >>> On Feb 2, 2012, at 11:09 AM, Byron Nash wrote: >>> >>> > I was wondering if there is a way to inverse a LUT? I'm applying an >>> Arri Alexa LUT to some footage for VFX work. Some of the elements are >>> graphics that need to maintain their color with and without the LUT. We >>> have been using a LUT on an adjustment layer and then turning it off before >>> rendering it. That way our VFX should be in the correct ranges for Color >>> Correction. This works fine for source footage but as soon as you need to >>> put a logo in there it gets weird. I'd like to be able to put a reverse of >>> the LUT on the logo/graphics and keep all that under the Adjustment layer. >>> In the past we have just sort of used levels and curves to approximate the >>> graphics with some success. But I'd like to do it the "right" way. >>> >>> >>> +---End of message---+ >>> To unsubscribe send any message to >>> >> >> > > > -- > --------------------------------------- > R.Christopher Biggs > Digital Ronin > --14dae93b5deab8571e04b80607a3 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable That's what I'm doing, and it works great until you have to put a p= iece of footage or a graphic in there that has a different color space. Wha= t we are trying to do is deliver a shot to color correction that does not h= ave the LUT applied.=A0

On Thu, Feb 2, 2012 at 8:52 PM, Chris Biggs = <christ= opher.biggs@gmail.com> wrote:
I =A0apply my LUTs to an Adjustment layer on top of my comp, then make it a= guild layer, as to not render out
no need to reverse then.


On Thu, Feb 2, 2012 at 12:51 = PM, Byron Nash <byronnash@gmail.com> wrote:
It's a 3D LUT from the Arri site, LogC2V= ideo_Rec709.

=A0

On Thu, Feb 2, 2012 at 3:13 PM, Brendan Bolles <= span dir=3D"ltr"><brendan@fnordware.com> wrote:
It depends on your LUT. =A0If it's a 3D = LUT, then it can not be inverted in general. 1D LUTs can often be inverted.= =A0LUT Buddy has an invert button that will be enabled when the LUT is inv= ertible.

In the 3D LUT case, imagine you had a LUT that was used to turn your image = black and white (desaturate). =A0As you know, no color operation could hope= to magically restore the color once it had been taken out. =A0So that'= s a clue as to why 3D LUTs can't generally be inverted.

If you created your 3D LUT using a series color corrections, your best hope= is to try to apply them in reverse with inverted settings. =A0You could th= en make a LUT of that operation to be your inverted LUT.

But usually you just try to come up with something close or deal with it on= a case-by-case basis.


Brendan



On Feb 2, 2012, at 11:09 AM, Byron Nash wrote:

> I was wondering if there is a way to inverse a LUT? I'm applying a= n Arri Alexa LUT to some footage for VFX work. Some of the elements are gra= phics that need to maintain their color with and without the LUT. We have b= een using a LUT on an adjustment layer and then turning it off before rende= ring it. That way our VFX should be in the correct ranges for Color Correct= ion. This works fine for source footage but as soon as you need to put a lo= go in there it gets weird. I'd like to be able to put a reverse of the = LUT on the logo/graphics and keep all that under the Adjustment layer. =A0I= n the past we have just sort of used levels and curves to approximate the g= raphics with some success. But I'd like to do it the "right" = way.


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<= /div>--
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R.Christopher Biggs
Digital Ronin

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