Alpha channels

I’ve read this in a tutorial:

You can save some time by setting up alpha channels of frequently used lines and shapes - just load them as selections when needed.
But I have no idea what an alpha channel is (I have a french verison of PS :-\ Can anyone explain?

pom :crazy:

i have a vague idea of how to use them, but explaining it is a whole other ball game.

it does save a little bit of time but if the image isn’t full of lots of things then its genrally just easier to do it normally.

also similar to this are the paths… for selections…

il be impressed if someone can explain

(but i arnt reknown fro my english anyway)

I have a slight idea on it, but I don’t use them often.

I am leaving soon so I can’t explain now. I will try and explain later unless someone with a better understanding of them explains before that.

I use 'em for complex (large) selections, such as a fullscreen scanline selection, or grids… anything really, plus they give an easier way of using the displacement and lighting effects filters.

I use 'em all the time :slight_smile:

example (for making a square with rounded edges, using channels):

Make a square/rectangle on a new channel layer. Gauss blur the bastard with at least 5, I use 10. The higher the gauss, the softer the edges.
Then go image->adjust->levels, and play around 'till the edges go sharp again, then ctrl+click the channel, go to layers palette again, make a new layer, and fill yer selection with the color of choice.

That’s how I make soft squares USING CHANNELS, there’s a MUCH easier way of doing it, this is just an example.

just make a circle, fill it with any color, go to channels tab and click the save selection as channel and you have the outline of the circle as Alpha 1

does that make sense? you can do this with any selection =)

Yup :slight_smile: that too :stuck_out_tongue:

Personally I just use it for selection manipulation…

http://www.techtv.com/screensavers/answerstips/story/0,24330,3399463,00.html

this should explain it =)

** Excerpts from article**
Alpha channels are masks through which you can apply effects. The alpha channel is an 8-bit channel, which means it has 256 levels of gray from 0 (black) to 255 (white). White acts as the selected area; black acts as the protected area. The level of gray in between determines the level of exposure. For example, 50 percent gray allows for 50 percent exposure. Alpha channels are basically specialized selection processes.

&

“The beauty of these alpha channels is that they can be saved, modified, or combined to create special effects. When you use the Lasso, you make a selection. When you deselect, the selection is gone. If you Save Selection (Select > Save Selection), it is sent to an alpha channel that can be recalled as many times as you need.”

Well said dude :slight_smile:

:A+:

*Originally posted by eilsoe *
**I use 'em for complex (large) selections, such as a fullscreen scanline selection, or grids… anything really, plus they give an easier way of using the displacement and lighting effects filters.

I use 'em all the time :slight_smile:

example (for making a square with rounded edges, using channels):

Make a square/rectangle on a new channel layer. Gauss blur the bastard with at least 5, I use 10. The higher the gauss, the softer the edges.
Then go image->adjust->levels, and play around 'till the edges go sharp again, then ctrl+click the channel, go to layers palette again, make a new layer, and fill yer selection with the color of choice.

That’s how I make soft squares USING CHANNELS, there’s a MUCH easier way of doing it, this is just an example. **

how can i do a new channel layer???

its all in the article, Bert Monroy is a photoshop god =) i am in so much awe everytime he is on TSS, i am drooling awaiting what masterpiece he will create this time

Open the channels panel.

Window/Channels or Window/Panels/Channels or something like that.

It is also the panel right next to the layers panel by default.

When in there you will see an icon at the bottom that looks like a page with the corner folder over. This creates a new layer in the channels panel.

The icon for a new layer in the channels panel looks like the icon to start a new layer in the layers panel.

Great explanation Mak. I guess I don’t need to explain much anymore…lol.

it is bassically another form of a layer mask… only morew used to for showing effects at differnt lebels rather than just the opacity of the layer

Thanks everyone. Actually, this was coming from this tutorial (don’t know if it has already been posted): http://computerarts.co.uk/tutorials/type/tutorial.asp?id=32297

pom :crazy: