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Levitateme
11-04-2003, 07:47 AM
I have never understood exactly what to do with levels in photoshop. anyone walk me through on why to use them and how? i know the sliders are like dark, midtones, and highlights...but i dont understand what i can dow with the channels...or anything withthem. anyone know of a tutorial? or walk me through on why to use this tool?

*RIBBLER
11-04-2003, 10:09 AM
Here is a tutorial (http://www.retouchpro.com/tutorials/index.php?m=show&id=50) which explains it.

I use this technique quite often to get more quality out of scanned images.

Cameo
11-06-2003, 10:50 PM
Thanks for the tutorial. One question though, as a footnote at the end it says

'And remember: always adjust levels using an adjustment layer!'

Can anyone explain to me why this is? You can step backward if you dont like any changes so what gives?

I must admit to never having used adjustment layers, can anyone explain their uses and where they can be found?

Many thanks

halo
11-06-2003, 11:06 PM
adjustment layers are just like the levels process except that they sit as a layer over the top of the image. The advantage is that you can change them without having applied them over and over again, you can fade them like a layer or even turn them off and you can apply them to the whole image or make them just affect the layer below. They can also have masks which can be re-edited like layer masks. They can be accessed by selecting a layer and hitting that little black and white circle button on the layers palette.

Extremely useful. In that tutorial you can see the adjustment layer in the layer palette :)

Stroker
11-06-2003, 11:10 PM
Adjustment Layers are good because they are non-destructive and can be tweaked and re-tweaked to no end. What's really cool is when you get into stacking adjustment layers. Curves + HSB is one of my favorite combos.

One thing I recommend is to mess around with Levels on a gradient, much like Levels (http://w3.chrlmi.cablespeed.com/~halmich/tech-slop/levels/index.shtml).

I don't have anything handy about adjustments layers specifically. But I do want to mention that they are masked. This is good for tweaking only parts of an image.

edit:
What halo said.
Heh.

Cameo
12-16-2003, 03:45 AM
Halo, I had a play with the adjustment layer and after re-reading your post I notice you said it was possible to apply the effect to the entire image or just the layer below. How do you get it to just effect the layer below? It seems to be entire image by default and I cant find the option to toggle etc.

Thanks

halo
12-16-2003, 08:13 AM
erm, force of habit makes me forget the key...but i think its option/alt...try holding option down when you create an adjustment layer and you should see an option tick box for "group with previous layer"....or if you have already made the layer, select the layer and hit crtl G, or option click in the tiny gap inbetween the 2 layers, or goto layers > group with previous.

The layers have to be right on top of the layer you want to affect. And it works with normal layers as well. :)

eevilmouse
12-16-2003, 03:52 PM
Adjustment layers also allow you to Layer the Effects. This way you can Burn, AND screen an Image, and its still non distructive. I alternate from Layers, and Applying directly to Layer, depending on what I need done.

(PS And yes if you hold down ctrl/Opt when you make the Layer it will allow you to group with the Previous Layer.)

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