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Posted on 06/11/07 11:57:54 PM |
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PhotoShoppie
* Posts: 3 Reply |
Alpha Channels
Hello, I have the previous CS2 version of this great Photoshop resource and had a question about Alpha Channels. Unfortunately, that aspect is not covered too specifically, although it is used in a few projects (making a coin, and creating metal effects). The projects seem to focus more on the use of lighting effects with alpha channels. Still, AC confuse me to no end (and I can't figure out why - I understand it's a way of selecting but I still don't understand how you can use these selections with the various filters and effects). Anyway, can somebody recommend a good, easy to understand source for explaining alpha channels and how they can be used to apply effects? Thanks for any help you can provide. PhotoShoppie |
Posted on 07/11/07 07:45:47 AM |
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Steve Caplin
Administrator Posts: 7068 Reply  |
Re: Alpha Channels
Alpha Channels are used to store selection information, just like a Pen path. The difference is that paths can store only hard-edged selections, but Alpha Channels can store selections with transparency. To make a new Alpha Channel, first make your selection using QuickMask, or whatever tools you like. Choose Select > Save Selection to save it to a new Channel, and give it a name. You can load this selection by choosing Select > Load Selection. And, really, that's what Alpha Channels are for. The fact that the Lighting Effects filter happens to make extra use of them in this way is unique to that filter; no other filters use Alpha Channels directly. Some 3D and animation applications, however, use Alpha Channels as a way to select cutout information from a Photoshop file. Hope this helps! |
Posted on 07/11/07 11:36:33 AM |
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Claude37
Souris superbe Posts: 46 Reply  |
Re: Alpha Channels
Hello, nothing to add to what Steve just said. That's enough ! But if you need more, look at this excellent book written by Scott Kelby: http://books.google.fr/books?id=8G5mCJPtI90C&dq=scott+kelby+channels+masks&pg=PP1&ots=-7k7DN7Zup&sig=xy3UCWhQnPOvrC-0akPCKYw7_FU&prev=http://www.google.fr/search%3Fhl%3Dfr%26client%3Dfirefox-a%26rls%3Dorg.mozilla%253Afr%253Aofficial%26hs%3Dxf3%26q%3Dscott%2Bkelby%2Bchannels%2Bmasks%26btnG%3DRechercher%26meta%3D&sa=X&oi=print&ct=title&cad=one-book-with-thumbnail#PPA4,M1 It covers everything about masks and channels in PS. And for the french users, it has been translated in french !!! 
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Posted on 07/11/07 12:09:13 PM |
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GKB
Magical Montagist Posts: 4057 Reply  |
Re: Alpha Channels
I totally agree with Claude about Scott's book. It is excellent and tells you just about everything you will ever need to know about channels. By the way, bienvenue Claude. Gordon |
Posted on 07/11/07 12:26:31 PM |
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Claude37
Souris superbe Posts: 46 Reply |
Re: Alpha Channels
Gordon, I thank you for your welcome and I wish you a good flight !!! |
Posted on 26/11/07 01:46:58 AM |
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zapat
Audio Artist Posts: 44 Reply  |
Re: Alpha Channels
i agree with you guys scott's book is really excellent. it's written during the cs and cs2 period. now cs3 comes with new black and white filter which you can integrate its function when selecting using channels. |