Channels 1 BChannels 1 B I have repeated this demonstration to try and make it very clear that the mask is a map. It is a map of “How Much?” instruction for Photoshop to use when a selection is created from that mask, and colors, adjustments, filters, or effects are added. It tells Photoshop exactly how much to affect the existing pixels with whatever you add. When you open an RGB, or CMYK color mode image in Photoshop, there are color channels created for each of those color components. Each of those individual color channels is a map which tells Photoshop “How Much?” of that color is applied to each pixel in the image. For example, if I want to look at just the Blue information for an image, I would click on the Blue channel’s name to select it, and turn off the ‘eyeball’ for all the other channels by clicking on the eye icon next to each of those channels.
You would see the grayscale image, shown below. This is the map of all the blue pixels in this photograph.
The white flowers show a lot of blue content, as the color white is made up of the RGB values, R 255, G 255, and B 255, or max content of all three colors. The blue, which is the central color on the gradient at the bottom of the image, shows white as it is pure blue. The little “blue” flowers show as a light shade of gray. Pure colors rarely occur in nature. The flowers look blue to us, but, in reality there are other colors in them. In fact, the highest amount of blue I could find in the flower, by dragging with the Eyedropper, and watching the Info palette was this.
As you can see, there is quite a lot of green, and red included in this flower. This color value came from near the center of the detail shown below. The blue channel detail of that flower follows.
CMYK channels use black to indicate the areas where there is more of a color, and white to show where there is less. This is the reverse of the RGB channels, or your default alpha channel settings. For example, here is the yellow channel.
The most yellow in the photograph occurs at the center of the big white flowers, a detail of which is shown here. As you can see, the yellow part is displayed as black.
The black channel in CMYK, which is the K channel, is shown below.
Again, to repeat, in the CMYK channels, white indicates areas where there is none of the color, and black indicates areas which are filled with it. You should not delete any of your color channels, but you can edit them using the various Image > Adjust commands such as Levels, and Curves, and filters such as the Unsharp Mask, and Gaussian Blur. Sometimes image problems are specific to one of the color channels and can be corrected more subtly by working, specifically on that color’s channel. Be careful, though. This is not for beginners. In addition, color channels can be used to make selections. If you have a distinctly colored object which would be very difficult to select, such as flying hair, or a tree with a million leaves, check the color channels. If one of them shows your object as clearly defined, and distinct from the background load that channel as a selection, and then use the Lasso tool with the Subtract from Selection option to remove unwanted
If you view an alpha channel with the other channels also visible, you will see it, not as a black and white mask, but as a semitransparent, reddish overlay to the RGB image. Here is what you would see if you had all channels visible, while editing the alpha channel I created with the various shapes.
If you turn off the color channels, you see the black and white mask used throughout this tutorial. Now that you know what channels are, and how to edit them, what can you do with them? Anything. Everything. Remember, channels are stored masks. Masks are selection maps. Anything you can do with a selection can be done better by using the flexibility, the editability of a mask. Selection tools, painting tools, and retouching tools as well as filters such as Gaussian Blur can be used to edit masks. Once you have your mask, and have loaded it as a selection, think of all the things you can do. Filters can be applied to selections. Fill can be applied to selections. Stroke can be applied to selections. Curves, Levels, Contrast/Brightness, Hue/Saturation, and Color Balance can be applied to selections. Use your imagination. Slightly off topic, but I will mention that most of the things which can be done with alpha channel masks also can be done with Layer masks. The latter are more like selections than masks since they are active, not passive maps, and they are specific to one layer. However, they serve the same function as the alpha channel masks, i.e. they tell Photoshop “How Much?” to affect the underlying layers’ pixels with the pixels in the layer that the mask is attached to. When a layer with a mask is selected in the Layers palette, a temporary channel for that mask shows up in the Channels palette. It only appears when the layer with the mask is selected. It can be edited in the Channels palette in the same way as any other alpha channel.
Here is a great article by Jon Seivert
Selling And Leasing Your PhotosExcerpted from Chapter 9 of Concert Photography. ________________________________________ Selling and Leasing Most music-business photographers I know began photographing musicians solely for sheer love and enjoyment. Shooting for profit was almost an afterthought that came when expenses began to mount and the quality of their work started drawing attention. That's a pretty good way for you to approach it while learning your craft, although that doesn't mean you shouldn't try to recoup some of your expenses as soon as you can. There are more places to sell and lease music-business photos today than ever. If there is any "secret" to selling your photos it is this: Make technically and emotionally strong photographs that stand out, and get them into the hands of the people who can use them, when they need them. Who will buy my photos? There are two ways to make money photographing musicians, music-industry figures, and products. You can freelance your work, or you can be hired by a band, a magazine, a record company, a manufacturer, or another commercial party. Obviously, it's better to get a fee, all expenses paid, and a guarantee of publication, but that will come only after you've proven yourself by freelancing. For the most part, you'll be shooting photos on your own and hustling prints and slides for publication to get your foot in the door. Once you get a few good shots and begin to acquire an inventory of artists on file, you'll find there are many potential markets. You can't sell them efficiently with a shotgun approach, however. Target marketing is crucial. Keep a running list of the names in your files, preferably sorted by idiom. That way you can tailor the list to the market you are soliciting. Bluegrass Now, for instance, doesn't care if you have photos of Smashing Pumpkins. They want to know what you have of Bill Monroe and Alison Krauss.
Buy a copy of Photographer's Market (Writer's Digest Books, 1507 Dana Ave., Cincinnati, OH 45207). Updated annually, it lists 2,500 photo buyers, including advertising, public relations, and audio-visual firms; art/design studios; book publishers; record companies; stock photo agencies; and all types of magazines and newsletters. Each listing provides addresses, phone and fax numbers, the editor's name, circulation, frequency of publication, subject-matter focus, photo needs and requirements, preferred means of making contact, and pay. Except for an informative section on small record companies, you won't find many specific music-business photo buyers here. Still, the information is invaluable self-education on how the market works. In addition to the listings, each edition contains a series of articles and interviews by and about successful photographers and publishing figures. You should be able to find Photographer's Market at just about any bookstore. Here are some potential markets and how you can reach them: Magazines Magazines present the most bountiful territory for getting your work published, if only because of sheer numbers. Appendix 1 lists several hundred publications that focus exclusively on music, musicians, or some aspect of the music industry, and there are hundreds more worldwide. Still, they represent only part of the picture. Think of all the other magazines where you find photographs of musicians or music-business figures on a regular basis, such as Time, Newsweek, Life, Vanity Fair, Fortune, Esquire, and Playboy. And that's just on the most visible level. The computer has put desktop publishing within the financial and creative reach of anybody who really wants to try it. Some efforts last only a few issues; others strike a resonant note with readers and advertisers and thrive. Either way, each new issue of every magazine requires a certain number of photographs, and some of them can be yours. Publications dealing strictly with the music or entertainment business represent the complete spectrum, with circulations ranging from the hundreds to the hundreds of thousands. Most are written to appeal to music consumers and are circulated by newsstand and subscription sales. There are also many trade publications geared to specific segments of the music industry, such as music-store owners, equipment manufacturers, and the recording trade. These publications have narrowly targeted, controlled circulations that are restricted to certain members of the music industry. With few exceptions-Billboardand Mixcome to mind-they are not available on newsstands. In recent years the most growth has come in the area of 'zines-publications with small circulations dedicated to a single subject. These are usually labors of love by one or two devoted fans with access to a computer. Music has proved a particularly fertile ground for these types of publications, with dozens of 'zines devoted to a single artist, band, or style of music. These can take just about any form, from well-written, slick publications featuring four-color photos-for example, Backstreets(Bruce Springsteen) and Dupree's Diamond News (Grateful Dead)-down to unreadable four-page newsprint rags. The next big-growth area is online publications. There are already quite a few on the World Wide Web, and new entries are coming online every day. Unless you've sneaked some great shots from the first three rows of a Barbra Streisand or Michael Jackson concert, your best bet when starting out is to target local publications. If you're into a musical idiom with a relatively small but devoted audience, such as blues, bluegrass, or folk, search out and join local or regional appreciation societies or clubs. They're great places to meet local musicians and knowledgeable fans, and many of them publish a magazine or newsletter to keep members advised of local concerts and events. These publications can provide an important forum for your photos, even though you probably won't be paid for them. They can, however, provide photo access to events featuring famous musicians in the idiom, as well as local bands and artists.
Search out the publications that focus on the type of music you most love to shoot. Appendix 1 of Concert Photography is a good place to start, but it's hardly all-inclusive. Each year, magazines disappear and new ones are born to take their places. Haunt newsstands constantly to look for new titles. Ask knowledgeable friends and musicians about ones they've seen. If you are bilingual, your potential market expands at least twofold, particularly if you speak Japanese, German, French, or Spanish. Visit your local library and consult Ulrich's International Periodicals Directory. In Vol. 3, you'll find the names and addresses of more than 1,700 publications around the world listed under the heading of "Music." (Of course, you don't have to actually speak the language to do business with international publications, especially if they have someone who speaks English, but it makes it easier.) The best, and most complete, listings for magazines published in the United States are Bacon's Directory of Magazinesand Burrelle's Media Directory. Both are updated annually and can be found at many libraries. If you hear about a magazine that caters to your interests but can't find it on a newsstand, write and request a sample copy. Many publishers will be happy to accommodate you if you indicate your interest in providing articles and/or photos, although you still may have to pay. It probably depends on how convincing you are. Keeping track of all the 'zines is a bit more daunting because they come and go so quickly. The definitive in-print guide is Factsheet Five(P.O. Box 170099, San Francisco, CA 94117-0099), which lists and reviews from 1,000 to 1,500 publications of every conceivable ilk in each quarterly issue. The music section is often the largest. © 1998 humble press. Material may not be used in part or in whole, unless permission is granted by humble press. To get your copy of the book go to this link Humble Press
Questions for Channels
2 Questions Channels
1. Is the colour green represented in the Channels palette?
2. What does RGB stand for?
3. How do you bring Channels to the forefront when you go to the “Layers, Channels, Paths” tool?
4. What are the default channels in the CYMK colour mode?
5. Can you turn off individual channels?
6. Why would you use an Alpha channel?
7. What are Alpha channels?
8. What does the "Load Selection" icon look like from the Channel Palette?
9. Can you choose any colour to use as a default colour for an Alpha channel?
10. It is impossible to generate a new grayscale document from a Split channel, true or false?
11. Selections are stored selection masks, true or false?
12. An alpha channel is a black and white map of your colour image, true or false?
13. What does “Anti-Aliasing” do?
14. Go to Photo-Shop and tell me what the RGB values are of the following colours
a. Red b. Green c. Blue
15. What does the “Linear Gradient” button do?
16. What does a “Diamond Gradient” do?
17. Does the “Pencil Tool” make soft edged strokes?
18. What does “Feathering” do?
19. What does the letter “K” stand for?
20. You should always delete all of your colour channels when you are done, true or false?
21. When a layer with a mask is selected in “Layers Palette, a permanent channel for that mask shows up in the Channels palette, true or false?
Practical AssignmentCreate digitally, a CD cover and inside folders by taking a variety of photographs dealing with music, musically instruments, and musicians. But don't limit it to that, stretch your creativity, on C.D. covers anything goes! What do you need to do: 1. Take pictures 2. Do the wording 3. Make it to size 4. Have it high enough quality to print with good resolution 5. Must be at least 6 pages 6. Put all the work in a file, including the raw photo images. Make sure the images are properly histogrammed and channeled.
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