Return-Path: Received: from mail-bk0-f41.google.com ([209.85.214.41] verified) by media-motion.tv (CommuniGate Pro SMTP 4.2.10) with ESMTP-TLS id 4615159 for AE-List@media-motion.tv; Fri, 03 Feb 2012 02:46:55 +0100 Received: by bkbzs2 with SMTP id zs2so2765756bkb.28 for ; Thu, 02 Feb 2012 17:52:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=xLpZdDR7HL9MV+UDx1Z0PVaclbv89jyqympYrMl9lwo=; b=kOJw7HZAKnq3x32OpJP2js/3KJ+Um2KnZTnl4vCOZca3o5ocsz002k4ydPe70k6N0i eGhdOoYdrexIEKjZ+m9Yz9porkbs39YcA7R3aKBVRkTWEnBFoUAxXvCWTlY9AQ3YvYNY IbquNd47BA0O66AIDMStGo2SxLM5Ee34KV4RM= MIME-Version: 1.0 Received: by 10.204.173.11 with SMTP id n11mr2490770bkz.120.1328233968183; Thu, 02 Feb 2012 17:52:48 -0800 (PST) Received: by 10.204.224.131 with HTTP; Thu, 2 Feb 2012 17:52:48 -0800 (PST) In-Reply-To: References: Date: Thu, 2 Feb 2012 17:52:48 -0800 Message-ID: Subject: Re: [AE] Inverse a LUT? From: Chris Biggs To: After Effects Mail List Content-Type: multipart/alternative; boundary=bcaec52d58f7da2a1904b8059135 --bcaec52d58f7da2a1904b8059135 Content-Type: text/plain; charset=ISO-8859-1 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 --bcaec52d58f7da2a1904b8059135 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable 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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--
= ---------------------------------------
R.Christopher Biggs
Digital R= onin
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