Is LUT adjusting valid retouching?

[Doug Nelson]

I'll go so far as saying I cringe whenever I read someone recommending LUT as a retouching technique. But I'll stop there and admit to ignorance.

The last time I thought about LUTs was back in the wild west days of non-standard video card support. So I may very well be confusing one LUT with another.

So can someone set me straight or put the lie to this technique? As far as I can tell it simply adds a layer of voodoo to using presets downloaded off the net.

[skoobey]

Re: Is LUT adjusting valid retouching?

It's like when someone says "try frequency separation". LUTs are a valid technique, but if you want to make a true work of art, you need to do a bit more than make one general LUT an call it a day.

[andrewrodney]

Re: Is LUT adjusting valid retouching?

LUT’s can be very powerful in terms of color correction as they are 3D in nature. I haven’t done much testing with them in PS because the samples provided are not very interesting or useful and mostly proof of concept. But I’m looking at a tool to build them that looks pretty slick that I heard about on this very fine forum:

http://3dlutcreator.com

[klev]

Re: Is LUT adjusting valid retouching?

They're used all over the place in video color correction. You can use LUTs to depict various source footage, which may have been captured differently. Aside from 3D LUTs, 1D LUTs also exist. It's just RGB colors tend to be highly correlated, so attempting that would probably lead to artifacts.

[insmac]

Re: Is LUT adjusting valid retouching?

Hmm I don't understand the question. What do you mean by "valid" retouching? Since one might use whatever he wants if he delivers a good output file. I mean, blurring skin.. that you may call invalid but it leads to poor results by definition, no way to go around it altogether.

Having said that, I've used it but for video correction, I had to grade a ton of small cuts for a longer clip (a video tutorial) and it helped a lot because I liked the interface more than Premiere Pro for that matter. Like I said in an earlier thread, some colorists I know export raw video frames to Photoshop and grade in it instead of using a dedicated suite. And the effect of their work is just as good. Depends what you like / need / can afford.

I don't use it for the stills because LAB curves in targeded hghlights / shadows work better for me and also color balance / gradient maps are good too if i want it to be done in a different way. But, it might work for someone since it's far more flexible.

[Benny Profane]

Re: Is LUT adjusting valid retouching?

What's a LUT?

[andrewrodney]

Re: Is LUT adjusting valid retouching?

Look Up Table. Support for LUTs in Photoshop now a few years.

[Benny Profane]

Re: Is LUT adjusting valid retouching?

What's being looked up?

[andrewrodney]

Re: Is LUT adjusting valid retouching?

A table is being looked up!

[skoobey]

Re: Is LUT adjusting valid retouching?

Is there any lunch being served at that table?

[andrewrodney]

Re: Is LUT adjusting valid retouching?

LUTs have been around since CS6, couple years now, nothing new. At least to those that follow the feature progression of Photoshop functionality:

http://www.photoshopessentials.com/photo-editing/color-lookup-cs6/

[chillin]

Re: Is LUT adjusting valid retouching?

What is LUT?

[Doug Nelson]

Re: Is LUT adjusting valid retouching?

I'm glad I started this thread. I WAS conflating two different things. Cringing gone. Now I'm intrigued.

[Benny Profane]

Re: Is LUT adjusting valid retouching?

Seems to be some fancy dancy way of doing an overall correction that only technically obsessed non retoucher experts use. Or don't, because they probably talk more than retouch. Pros have countless ways to achieve the same result.

Pros also have developed finely tuned BS filters. They can smell hype coming down the pike from Adobe before it's even announced. Every time they came out with a new version of Photoshop, there were probably ten new "features" that I ignored, but seemed to generate a lot of excitement in the amateur blogosphere. Sigh.

[Doug Nelson]

Re: Is LUT adjusting valid retouching?

It does strike me as being reminiscent of styles and presets, but looking at that lutcreator app makes me think there are some interesting possibilities. Maybe not for the retouching sphere, but definitely for the more creative or arty side of things.

It's really just the same old thing, since there really is only one thing. But it's a different way of looking at that, which may be useful to some, useless (or worse) to others.

I do find the absolute mapping (one specific number becomes another specific number) makes more sense to me in some ways than the relative mapping (add or subtract a number or percentage from some number). And there is a comfort factor for those coming from a film background (or that could just be me). But it does add an unfortunate layer of abstraction without an expensive additional program.