Real basic Channel question regarding cracks challenge

[Ferlin]

I've been working with Photoshop for a year now and I should know how to do this - but I don't. I tried using Moths formula for making cracks - he said make alpha channel -clouds -noise blur and other things and I did that and it worked nice - so when I click back into layers my alpha layers effect dissapears. How do I apply these channel effects back into layered RGB image. Also the only way i can see the alpha channel is when I turn off the RGB eye. Hope this makes sense! I have avoided using channels because heven't seen the need for them, with layer masks and all the other stuff PS. has -but I want to understand them now. ;\ ;\ Ill' read more about them- the only thing I want to know is simply - How do I apply these effects from my alpha chhanel. \:]

 

[MsOz]

Ferlin, you then have to load your alpha channel as a selection from the Select tab on the menu bar.

Hope this helps!

 

[Ferlin]

Ms Oz please don't laugh. I highlighted the Alpha layer and the marching ants show up and the History pallet says load selection.. now what? Copy and paste. oh I think thats it... yeah.. got it in there.Thank you! Guess I'm still in the first Grade

 

[kiwi]

This can be tricky Ferlin,dont be to tough on yourself


K the trick to the effect is that the alpha channel is loaded in to "lighting effects filter" where the alpha channel is accessed.What the lighting filter does is makes any pixels {when incooperated with the texture channel setting} that are white 100% raised,any which are black 100% intruded,so white extruded,black intruded,and anything in shades of grey either in or out depending what side of the scale they are on,oh and 50% grey does not have a reaction at all as its neither one or the other


Here is the alpha channel I made.....I painted a little of it.

 

[kiwi]

Here is the lighting filter.At the bottom of this window is a button called texure channel,in the texture channel sub menu your alpha channel name will be there,just browse down and click on it.What happens now is that you have the choice of all the different myriad of settings for your light,you have omni,spotlight etc,but your texture channel and its shades of grey will be recognised by the computer as a guide for how much to raise or lower certain areas of your image,so thats how you get your bump like effect


Oh and the slider that says height will intensify the effect even more.

As Stroker likes to say,play,fiddle,learn



Stu.

 

[kiwi]

And the result with a bit of gradient for light and some extra tweaking.

 

[Ferlin]

Good Demonstration Kiwi. But why do this in channels at all? Why not just do it on a layer with the lighting effects filter ? I know you can get contrast in an image in one channel that you can work from to make difficult selections. I am reading about channels so please don't feel you have to explain channels to me. Also , last year Eric wrote some good explanations about channels when we were playing with clouds and difference clouds where channels open doorways into all kinds of color interactions I'll start doing some beginner tutes on channels so I don't miss out on this stuff. \:] [excited] Duh- the lighting effects filter can only be accessed using an alpha channel, right. Okay ;\

 

[Ferlin]

The keeper

Am reading your intrduction to channels. Can't belive I skipped over it. I'm finding that very useful. Thanks

 

[Rantin Al]

Good Demonstration Kiwi. But why do this in channels at all? Why not just do it on a layer with the lighting effects filter ?\

Ferlin Think of the Channel as a re-usable item. If you apply any filter on a textured layer, the texture will be changed. But if you load it as a selection from the Channel, you will retain the texture for use on another layer or mask.

Cheers, Al.

 

[kiwi]

np Ferlin


Mark has a tute in the intermediate section of the front page on carving and chiseling text,that also uses the lighting filter and is very well written/explained