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View Full Version : Any clever way to match the value of two photos?


schioler
03-02-2010, 01:18 PM
hi there ..
i wonder if theres any clever way of matching the value, and hue
of two pictures .. ?

u know when importing 2 photos into a composition and u want
those two photos to match in value and colortheme..

im working in photoshop..

thanx in advance..

Wizdoc
03-02-2010, 05:41 PM
Work with one thing at a time.

Throw an Adjustment Layer on top of everything with -100% Saturation.

Now just using Curves, adjust the values so they match. It's a lot easier to see how they match since the image is grayscale at this point.

Next, turn off the Saturation Adjustment Layer and tweak the hue and saturation, but don't touch the values.

Suirebit
03-02-2010, 07:18 PM
There is a photoshop plugin which tries to do exactly this, but to be honest, isn't this what a matte painter should do? Train his eye to sense photorealism and do such things without the help of a recipe/tool? :)

So there is no 'clever' way, it's more about experience and familiarity with the software.

schioler
03-02-2010, 07:22 PM
wizdoc - thanx a mill for ur answer that was what i was looking for..

i was not looking for a smart plugin, just a "workflow" kinda way to
approach it .. ;)

JJASSO
03-02-2010, 07:24 PM
in my experience all the Proffesional matte painters I know , (me included) , nobody use a special plug in to do that, as Suirebit said, you have to train the eye in order to spot errors in values and this will make your brain spot any other error in the future as well as make you eye better for light, color and composition

schioler
03-02-2010, 07:30 PM
yes i know .. training the eye - but again i was not looking for an
plugin to do the work .. ;)

Suirebit
03-02-2010, 07:42 PM
no, but you were looking for a recipe (or 'clever' way) and the truth is there isn't one...art is not science and doesn't work like programming. Like what's a clever way to do a rollover effect :) It's all about experience, after a while the brain will tell you what to do, so keep practicing :)

schioler
03-02-2010, 07:58 PM
thanx.. i will indeed ..
i can see "clever" is a bit misleading here.. i just wondered how u pros
was approaching that, and if theres was a workflow to get similar tones, values etc.
when combining those pictures. I use a hell lot of adjustment layers in my workflow,
and i often get confused with all those .. i am fare from a pro like u guys, and i am
still learning ;)

JJASSO
03-02-2010, 08:26 PM
well , I use levels and curves to match dark and bright values and nothing more, just tests after test till I like it , I also add 2 adjustments layers on the top of my layers one, hue and saturation without color saturation at all, this will make all my psd comp black and white , and with this I can spot errors on my black and white values , the second would be a levels adjustment layer , with the whites pushed up , this will reveal the darkest values in your comp as well, use one after the other never both at the same time, this won;t do anything for your specific layer but will just help you reveal the area where you need to adjust your levels

tide78
03-03-2010, 07:13 AM
I agree and disagree with everything said here. While I often hear about the necessity of artists training their eye and such, (I do agree that you need to train your eyes. Foolish to think otherwise.) There's also an element of technology involved. Mattes aren't done on Masonite or glass anymore.. We have digital tools at our disposal, and with the right amount of know how, we can use them to bend the "rules" to our advantage..

That being said, a technique I like to use for getting things in the similar color/value ballpark is to go through each color channel, R,G,and B and do a curves adjustment for each, matching the values for each color channel. This can be done with an adjustment layer or simply straight to the layer itself. Sometimes this quick process will nail it right off the bat, and other times it may take some extra massaging. There's a billion ways to do anything in Photoshop. What's great about it, is that you could do the same thing with an infinite combination of steps. I suppose you could call what I described there a "recipe", but it's not really a recipe. It's a solution to a mathematical problem.

The way I see it, is that I can still be an artist, but it makes it a lot easier for me to wield the power of technology if I consider what I'm trying to accomplish in the terms the program I am using to solve my problem. The computer obviously doesn't know what a color is, only a matrix of numerical values that it assigns visual feedback to via a series of predetermined rules. Therefore, If I deal with my images on that level, I can become more efficient about how I match one numerical value to another. Let's be honest, I'm an artist in my own time, and when I'm getting paid to matte paint, I'm getting paid to be as efficient of an artist as I can be. And what employer doesn't value efficiency?

This is not to say that I should disregard any artistic knowledge or shrug off any advice about training my eye, or learning how to see color, value, and light better than I currently do. That is the fun part in my opinion, is that I can constantly grow as an artist, and at the same time, I can learn how to arrive to my artistic conclusion quickly if I am able to take technological shortcuts rather than fumble through sliders and dials...

Hope that was useful for someone... :D Of course please remember that's just my opinion and outlook on the matter. I strive personally to be as avid a technician as I am an artist.

schioler
03-03-2010, 08:11 AM
thanx alot .. really many helpfull comments ..
nice to hear how u guys do it..

nickmarshallvfx
03-04-2010, 07:17 PM
Tide78's technique of matching each colour channel individually is a good one. I use that extensively when doing paint work in Shake. If I need to create a patch for an area of a shot, its the first thing I try to get the patch to blend seamlessly.

everlite
03-06-2010, 04:27 PM
The keys areas to look out for are the black values and odd hue changes.

To add to a few techniques above, drop in a black and white adjustment layer and note the values, you can do this using the info panel, hovering the color picker over one areas and noting the changes to the LAB values, you can then go in and adjust the target area with levels and curves as required to match these values.

Another technique; slap on a hue/saturation adjustment layer to the top, wack up the saturation really high and this will make the colors more vivid and pop out any issues, you can then tweak the underlaying layers as required. Don't forget to hide any preview layers when sampling from the artwork otherwise it will take into account the preview layer too!

Another technique is to sample colors from one layer/element and using the brush with color mode selected; paint into the target area at around 50% also click the little button in the layers panel that says lock transparent pixels so it only paints into the layer itself. Not forgeting to unclick this and reset the brush to paint in normal mode afterwards.

Match and replace color tools can work quite well sometimes, a little hit and miss and need pulling back a little.

Dave.

Suirebit
03-07-2010, 08:36 PM
Very interesting tip with going into each channel. But I still think the fastest way is like Jaime said - drop a desaturation layer on top, match the levels in grayscale, then turn it off and match the color with whatever tool, I like to use Color Balance.

schioler
03-09-2010, 04:41 PM
YES indeed! ;)
thx mate..

stevocreative
03-22-2010, 03:55 AM
I generally carry out almost all color manipulations using curves. I avoid other adjustment layers which typically offer just a limited aspect of the functionality provided by curves. However, to master curves you do need to have a feel for the mathematics underlying them, and a keen eye for color and tone that only comes with practice.

That having been said I was intrigued by the notion of a clever "plug-in".

Googling on the subject I was reminded of "Match Color" (which I now see everlite has also mentioned) in Photoshop which is probably the closest you'll get to a "clever way of matching the value of two pictures". I've become so reliant on curves that I'd forgotten it actually existed. Maybe I'll try it out if I'm ever struggling with a color adjustment :-).

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