Meeting 3

Chi fa da se' fa per tre (e per altri trentatre)

Topics: File naming conventions, more tools basics, selections

Files needed from the server:

For Fun: A list of some strange Photoshop mistakes.
http://creativenerds.co.uk/inspiration/30-horrific-commercial-photoshop-disasters/

Here's another...
http://www.photoshopdisasters.com

File Naming conventions
In a mixed platform world of Macintosh, Windows, and Unix computers, you must pay attention to how you name your file. On PCs, you usually append a three-letter file extension after the file name to tell the computer what program to launch when it is double-clicked. Programs on the PC do this automatically, but the same programs running on the Mac often do not. However by default Photoshop (starting with version 5.5) appends the proper file extension to various file formats, i.e. JPG, TIF, PSD, etc. This is a Photoshop preference that can be altered, but unless there is an unusual need, do not change it.

Never, NEVER simply select the file extension and change it (i.e. myfile.tif --> myfile.jpg) in an attempt to change the file format. That does not work! You must instead resave the file from within Photoshop in the new format you wish to use.

There are additional things you should avoid when naming files for use on all platforms (i.e., web images, multi-media/CD presentations).

Things to avoid:

Don't use odd punctuation or characters in the file name. For example, don't use #. %, forward or back slashes, ampersands, and question marks or any other strange glyph. Stick mostly to letters and numbers. Dashes and underscores are good for separating words.
Good: my_file.jpg
Bad: my/file.jpg

Don't put more than one period in the file name. Use only one period at the end of the file name just before the three-letter suffix.
Good: very_big_splash.jpg
Bad: very.big.splash.jpg

Don't omit the 3-letter suffix. Add the correct 3-letter suffix to the file name if none is created by the application program. ALL web browsers require a suffix to be able to tell a picture file from a text file, for example. Don't add inaccurate suffixes either. If you name a TIF file "goodpicture.jpg", the picture won't display properly on a web browser. For a list of PC file name suffixes, go to suffix.html.
Good: promo_pic.gif
Bad: promo_pic.newone
Bad: promo_pic

Avoid spaces in filenames. High-speed Unix-based web servers dislike having spaces in the file name. Your pages and files with spaces in the name may work on a Mac or PC server, but if you ever migrate the files to a Unix server, you're could be in trouble. Most experienced web designers use underscores in the file name to separate words for clarity.
Good: my_new_car.jpg
Bad: my new car.jpg

Note that spaces in a web address are replaced by confusing "%20" symbols on the url. Click this link and look at the url line on the web address to see the confusing text.

Gradient filling a selected area
Open Golfer Silhouette.tif (found in the Exercises 1 folder).

Change the file's Mode to Grayscale, then change it once more to RGB Color...
    (Image> Mode> Grayscale, then Image> Mode> RGB).

Select the background. We'll find that the venerable Magic Wand tool works perfectly well with this picture. Photoshop CS3 introduced a useful Quick Selection Tool that is grouped with the Magic Wand tool. The Refine Edge button on the Options bar for this tool appears to give a fair amount of control over the initial selection. However, we won't use it for this exercise.

Choose the Magic Wand tool (NOTE: don't confuse it with the Quick Selection Tool).

Turn anti-aliasing OFF in the Magic Wand tool's Options bar (uncheck the box). Anti-aliasing should be OFF when selecting black and white line-art like this picture or you could get grayish edges on the artwork after subsequent editing.

Select the white background around the golfer with the Magic Wand tool by clicking on it. You should see an animated marquee - often called 'marching ants'.

Fill the selected background area with a gradient fill of your choice of colors using the Gradient Fill tool and different background and foreground colors.

After filling with a gradient, then try to select the background gradient with the Magic Wand after filling to see how poorly the Magic Wand works on objects comprised of varying colors. The workaround for this file is to first select the golfer silhouette then choose Select>Inverse to select the background. That works because the silhouette itself is all one color (black).

More tools using Clocks1.tif

Open clocks1.tif in the Exercises 1 folder. Use Zoom tool to see how the faces are backwards. Then use Image> Image Rotation>Flip Canvas Horizontal to correct the mistake.

Handy Tip: When you are zoomed in on a picture, you sometimes need to get to another part quickly. To do that, hold the keyboard spacebar down to change whatever tool you are currently using into the Hand tool. This enables you to quickly pan around the zoomed view. When you release the spacebar, the cursor switches back to the tool you were using before. This saves a lot of mousing around between the picture and the toolbox.

TIP: Beginning in CS4, "Flick Panning" is enabled as a default. This lets a panned picture "coast down" to an eventual stop. To disable Flick Panning, go to Photoshop>Preferences>Tools and uncheck "Enable Flick Panning".

Practice using the Dodge/Burn, Sharpen/Blur tools and their options on the Options bar.

Clone stamp tool -- select a source area by Option-clicking from where pixels are to be copied, then move the mouse to a new location and begin painting. Notice how the cross-hair cursor shows where pixels are being copied from, and the other cursor shows where they are being copied to. A common problem for beginners is selecting a source point too close to the destination point. Odd repeating artifacts may appear once the painting source indicator overlaps the already retouched areas. Another problem is trying to do all the retouching in just one extended click/drag of the mouse which will also invite repeating artifacts.

Note: Beginning with CS4, Photoshop shows the clone tool cursor with the content carried inside. If you wish to return to the earlier way the rubber stamp tool worked, choose Window>Clone Source to show the Clone Source palette, and uncheck Show Overlay in the palette.

Selecting an area using the lasso tool

Open Clocks1.tif from Exercises 1. The Magic Wand tool won't work on this picture's background. Use the Lasso selection tool to select the clocks then choose Select> Inverse to select the background. Gradient fill the selected background.

After selections have been made, they can be modified. Use the Option key with any selection tool to remove parts from an existing selection, and use Shift with any selection tool to add additional parts to an existing selection. In summary....

Shift adds,
Option subtracts!

More About Selection Tools
There are other selection tools that can be used and combined to add power. Additionally, using the Option button while making your first selection can change the behavior of the tool to that of another.

Open Clocks1.tif in Exercises 1.

As discovered earlier, the Magic Wand tool won't work on the gradient-tone background. When you click on a color, it looks for similar colors to select. When the colors or tones are different enough, they won't be selected.

Try using the Magnetic lasso tool (click and hold on the lasso tool icon to display it) but notice how it fails in areas where image tone matches background tone (low edge contrast).

Try the Magnetic lasso again, but hold the Option key in troublesome areas to temporarily override the automatic selection function. Release the Option key in areas of high contrast edges to resume automatic selection of image edges.

When you are making an INITIAL selection, hold the Option key to prevent the regular lasso tool from closing and to easily create straight lines in the selection. Click and hold to continue drawing curved selections. If you have the straight line lasso tool selected, hold the option key to create curved lines. Remember that the Option key changes behavior once a selection has already been made (it subtracts from an existing selection).

Select>Inverse and fill with a different color gradient. (Select> Inverse chooses opposite parts of the picture from what was selected previously.)

Don't forget how to modify selection areas -- subtracting from selection (Option key), adding to a selection (Shift key).

The Polygonal Lasso tool allows you to select straight lines easily. Holding Option during the initial selection permits tracing curves.

Selection tool tip: If you are switching between the rectangular and the ellipse marquee tools, press Shift-M to toggle between them.