frequency separation-questions?

[bilguitei]

Well i have been trying to watch tutorials...And i watched one in retouchpro and also from anyother websites....I still cannot understand it that much...What's the purpose of it?And why do i have to use it?Please if you know very clear and detailed tutorials on internet,help me to find it????

[ShadowLight]

Re: frequency separation-questions?

you can make much less "destructive" corrections on your image

one possible use is this:

http://www.retouchpro.com/forums/photo-retouching/31206-photonictools.html

you don't need to know why or how it does it,
just move the sliders to get the effect you like

[oneredpanther]

Re: frequency separation-questions?

Maybe you don't "have to use it" just yet.
It depends on where you are in your progress as a retoucher, I suppose.

There are many many more things to learn before you get to frequency separation. My best answer is probably that if you don't know why you need it, then you don't need it yet.

The purpose of frequency separation is to split up skin into two (or more) layers

1. A low frequency 'underlayer' that the skin's color, tone and shape is held in. This is a smooth-looking layer that you can change without modifying the texture of the skin.

2. A high frequency 'overlayer' that has no colour or tone but contains just the 'details' of the skin, such as pores and hairs and spots and wrinkles.

By editing each of these layers independently you have fine control over the retouch.

Imagine accidentally spilling paint all over a painting, then trying to remove it again.
This would be so much easier if you could split the original and the spots into different layers and just clean the top one, and this is the essence of frequency separation.

Panth

[mistermonday]

Re: frequency separation-questions?

2. A high frequency 'overlayer' that has no colour or tone but contains just the 'details' of the skin, such as pores and hairs and spots and wrinkles.
Panth

Just one clarification to what Panth has written. The high frequency layer actually does contain color. If you wish to see the color and where it resides, just do a Ctrl+U (Hue/Sat) and drag the saturation slider all the way to the right.
In a normal freq separation, the HF layer contains all the edges which are equal to and less than the chosen Radius and the colors that resided on both sides of those edges are intensified (contrast has increased along those edges). Conversely on the Low Frequency layer below, the same edges at the same radius have had contrast reduced (edges blurred). When the two layers are added together (function of the Linear Light Blend mode) the result is the original image. GB + HP = Original.
You are pretty safe using the healing brush on the HF layer because it tend to copy and blend in texture without taking all of the color. However you need to be careful using the Clone Stamp tool when trying to clone texture from an area of very dissimilar color because the clone tool will take all of the color as well and you can end up with a mess.
Regards, Murray