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Preface
PART
In fact, on September 10, 2003, Kodak, the largest film company on the planet, announced that it was no longer investing money in the development of traditional film technologies. Kodak, which generated tens of billions of dollars in profits for more than a hundred years, admitted in a single statement that film - its cash cow - was no longer a growth business.
What Do You Mean by “Digital Photography”?
Digital photography focuses on speed, which is one of the advantages of digital film. The fastest and cheapest way to get a digital photo doesn't even involve a PC or fancy color printer.
Why Flash Media Is Important
This is simply one of the cheaper ways to get involved. Take some photos and post them on the net using one of the free web page builder websites offered by Yahoo.
Is Digital Photography Expensive?
Is Traditional Photography Really Less Expensive?
Consumer-grade digital cameras are not capable of higher resolutions than you would get from a 35mm camera with a third-rate lens. Low-end digital cameras currently match instamatics on price, but above that consumer level, a serious digital SLR camera body costs two to three times more than a traditional camera body.
Capture Delays
Your goal should be to find a camera that has no lag, or at least a lag you don't notice.
Sensor Resolution and Crummy Lenses
The RGB Color Space
For this reason, the CMY color space is called a "subtractive model". The black (K) component is added so that true black can be printed on paper (versus an artificial black of the three colors). This color space makes it possible to compress the chrominance (colors) in an image without affecting the brightness.
The CCD Image Sensor
Always try to use Adobe RGB if your camera can capture in that color space.
CCD and Color: Using a Color Mask
Three separate pixels dedicated to red, green and blue are combined in software to create a virtual pixel at the center of these sensors. By placing three pixels together to create a virtual pixel in the center, the amount of space between the actual pixels and the virtual pixel is considerable.
CCD Competition: Low-Cost CMOS Image Sensors
In addition, the imprecise sensors used with a Bayer mask require "blur filters" to reduce color artifacts. The random appearance of artifacts and the required blur filters force the software to reduce sharpness.
What About Foveon?
Aliasing and Other Imager Problems
It is created using the color data in the pixels around it - a drawback of the Bayer mask method. Each manufacturer uses different software to increase the color and detail available to the number of pixels in a CCD camera.
Highlights and CCD Sensitivity
Digital Camera Technologies and Standards
Click once on an image in the file browser, then view its metadata (data about data) on the left side of the browser window. If you cannot see the file information on the left side of the file browser, click the double arrows to display the other half of the file browser (see Figure 2.9).
Exif Print
You can also view an image's EXIF metadata by choosing File, File Info in Elements or Photoshop. The most useful information is probably the date the image was created and the X and Y sizes, which tell how big the image is in pixels.
PictBridge
Direct Print
Design Rule for Camera File Systems
Digital Print Order Format
The two you will notice first and most often are battery drain and shutter lag. Today's digital cameras evolved from film cameras and require the same knowledge of sensitivity, color and resolution.
Choosing a Color Film
Types of Color Film
Negative Film
Reversal Film (Slide Film, Transparency Film, or “Chromes”)
Professional Film
Professionals keep foil refrigerated until use and develop it as quickly as possible. However, once the film is opened (you take it out of its plastic wrap), it is better to store at room temperature and should be exposed and developed immediately.
Films for Specialized Color Balance and Exposure Times
Professional film is shipped with its qualities near their peak and refrigerated by camera shops to ensure it is in the best condition. Conversely, amateur film may be shipped before it is ready because the manufacturers expect it will not be used immediately.
Selecting and Using Film
Negative or reverse "professional" film is also designed and manufactured for professionals who require accurate color balance. Professionals usually buy large quantities of film, preferably all from the same production batch, and shoot test rolls to determine its exact ISO and color balance.
Color Balance and Film
Do You Need a Film for a Special Purpose?
Storing Film Properly
Film Speed
Film Speed Rating Systems
The higher the number in a given system, the faster the film—and the less light you need for a correct exposure (see Table 3.1). Slower film speeds are used for portrait photography because maximum brightness is desirable (see Table 3.2).
Film Speed and Grain
Recent advances in technology have changed the previously fairly direct relationship between film speed and graininess. The DIN rating adds 3 to the rating every time the film speed doubles.
Fast-Speed Film: When Speed Is Essential
Medium-Speed Film: The Best General Purpose Film
If the light is moderately bright, medium-speed film still allows you to use a relatively fast shutter speed, so you can hand-hold the camera or take sharp shots of moving subjects. The slowest film speeds would require a tripod to hold the camera still during extended exposures of the same scene.
Slow-Speed Film: Maximum Detail
How Film Responds to Light
This chapter focused on film, which you might not expect to see in a digital photography book. Focal length. You've probably heard the numbers surrounding lenses, such as a 28mm lens and a 400mm lens.
Lens Focal Length
Focal length also controls the angle of view, the amount of scene displayed on a given film size. As a result, long lenses must include in a given film size less of the scene in which the subject appears.
Normal Focal-Length Lenses
The difference between what is considered a normal focal length lens for each type of camera is described in Table 4.1. A lens with a normal focal length has certain advantages over lenses with a longer or shorter focal length.
Focal Length and Digital Cameras
Long Focal-Length Lenses
Because a long lens has less depth of field, objects in the foreground or background can be photographed out of focus, bringing out the sharply focused subject. With these devices, the effective length of the lens increases, but less light reaches the film.
Short Focal-Length Lenses
A tele-extender or tele-converter contains an optical element that increases the effective focal length of a lens. It attaches between the lens and the camera body and magnifies the image of the lens on the film.
Special-Purpose Lenses
Fisheye Lens
Because a wide-angle lens can be focused close to an object, it is easy to get this kind of exaggerated aspect ratio. It's not a lens for every situation, but it can produce surprising and effective views.
Macro Lens
Soft-Focus Lens
Perspective-Control Lens
Photoshop, these lenses were the only way 35mm and medium format architectural photographers could correct the distortion of buildings.
Catadioptric (Mirror) Lens
Automatic Focus
It also allows you to photograph fast-moving objects that are not in the center of the frame (see Figure 4.8). Some wide-area AF systems use light bouncing off your eyeball to determine where you're looking in the viewfinder and thus which aspect of the image to focus sharply on.
Types of Autofocus
Active autofocus emits a beam of red light that the camera uses to measure the distance to the subject. Passive autofocus uses the contrast in the scene to determine when the subject is sharp.
Center-Weighted Autofocus Lock
After you lock onto a subject, some cameras predict where the subject is likely to be next, keeping the subject in focus even as it moves across the frame. The system works particularly well when the subject, such as a racing car, moves towards or away from the camera at a constant speed.
Focus and Depth of Field
Controlling Depth of Field
To decrease the depth of field and make the scene in front of and behind the subject clearer, use a wider aperture, such as f/2.8 or f/4. To decrease the depth of field and make the scene in front of and behind the subject clearer, you can use a longer lens or move closer to the subject.
Lens Focal Length, Aperture, and Light
You can increase depth of field by switching to a lens with a shorter focal length or moving away from the subject, although either choice will also change the image in other ways. If the focal length of the lens is 300mm, you'll need a 75mm aperture to get an aperture of f/4.
Digital Cameras and Color Balance
Daylight film is balanced for 5600° Kelvin (or K) light and produces accurate colors with midday sunlight or electronic flash. The indoor film, called type B or tungsten film, is balanced for 3200°K light and produces excellent colors with professional quartz-halogen lights (powerful lights up to 1000 watts).
Color Balance and Slide Film
Color film can record colors that your eye doesn't see when the picture is taken. This is because incandescent bulbs produce more light in the red wavelengths than daylight.
Exposure Latitude
Some professional digital cameras capture 36 bits per pixel instead of 24 and can handle high-contrast scenes better than cheaper point-and-shoot digital cameras. Although 24 bits per pixel means millions of possible color combinations, 36 bits per pixel increases this capacity to billions.
Film Latitude
In contrast lighting, color reversal film and most digital cameras cannot capture the full range of brightness. In scenes with very bright highlights (such as snow or sand) and very dark shadows, the brightness range of the scene (its total contrast) is greater than the exposure range of the film or sensor.
Working with Scan Software
Making a Scan Step by Step
Set the color space in the scanner software: Grayscale, RGB or CMYK, the bit depth (if necessary) and the sampling rate. More advanced scanner software allows you to correct the preview image for brightness, contrast and color balance.
Determining the Samples per Inch of a Scan
An image in a print 8 magnifications × 250 pixels per inch 2,000 samples per inch An image on a monitor 4 magnifications × 95 pixels per inch 384 samples per inch A poster size image 48 magnifications × 50 pixels per inch 1280 samples per inch Offset (magazine ) 8 magnifications × 300 pixels per inch 2400 samples per inch printing on 120 screen. For example, a magnification of 10 for a print at 200 pixels per inch requires a scan of 2,000 samples per inch.
Scanning for Internet Output
But what if the output does not match the aspect ratio of the negative or print. If the image is scaled naturally or after cropping, determine what the output requires in ppi (pixels per inch).
Scanning for Inkjet and Dye-Sublimation Output
Scanning for Laser and Offset Printing
Alternatives to Scanning
This format is more powerful and flexible than the TIFF format, but is not used as often. This format is commonly used when importing work into QuarkXPress, Adobe InDesign, PageMaker, and.
JPEG File Format
Excellent image fidelity. The JPEG format is designed to be fast and provide high fidelity compressed images. This format is also designed to be customizable, allowing users to "dial in" the level of compression they want.
How JPEG Works
Baseline optimized. This encoding uses an improved compression algorithm that results in better compression with the same quality as baseline sequential. Photographic Experts Group and offers a scale multiplier that the user (you!) can adjust: the Quality slider in Photoshop.
The Replacement for JPEG: JPEG2000
When the JPEG file is opened, it is decompressed based on the file header information. When browser manufacturers finally implement this standard in their browsers, the appearance for JPEG2000 may improve.
TIFF File Format
The first byte is 20, which represents the number of X's it found in the file. If you're doing a lot of work on an image and using a Photoshop product, save it in the Photoshop format.
Using PC Inspector File Recovery
If you are desperate and need to recover files now, the next section will help. If you're not exactly in panic mode, you might want to skip to the end of the chapter to learn how a file system stores files first.
Recovering Lost Images from Flash Media
These sliders are preset to half the capacity of the flash media unless the media is small (less than 32 MB). Sliding the bottom slider to the right forces the software to scan the entire flash media card.
Recovering Specific Images
Partially Corrupt Files
Select your camera's megapixel size and read on to find a suggested default file size setting. Medium (Normal JPEG compression, Enter. Non-RAW or TIFF image sensor size resolution) Default file size.
Filesystems at Work: The File Allocation Table (FAT)
Further cluster numbers are found in the file allocation table (FAT) and read from the corresponding clusters in the data area. It then looks at the corresponding first cluster entry in the FAT and finds where the file continues (next file cluster number).
What Happens to Lost Data
Preventative Maintenance: Defragmenting Flash Media
FAT16: The file system used for almost all flash media is based on a 16-bit binary number to hold cluster numbers. Hardly any flash media is formatted with the FAT32 file system, even with these advantages (smaller file size, larger capacity, etc.).
Another Disaster Point: USB
An interesting irony of FAT32 vs. FAT16 is that you can now buy high-speed flash media that stores photos much faster than older media. In the Safely Remove Hardware dialog box, click on the flash media reader to highlight it.
Finding an Image on Your Computer
Editing with Photoshop Elements
Printing Resolution
Resizing an Image Step by Step
If Resample Image is checked (see Figure 9-4), Elements changes the number of pixels in the image. When the Image Size dialog box appears, clear the Resample Image check box (see Figure 9-5).
Resampling an Image
Change the print size of the image by typing a number in the Width, Height, or Resolution (pixels per inch) field. If you enter a number in this range in the Resolution box, the image will print fine on the printer.
Rescan or Resample a Photo
Resampling 101
The number of pixels will automatically change to fit the size of the new document (print).
Modifying an Image in Elements
Perspective Correction in Elements
If you don't like the change and aren't sure how to undo it manually, just click the undo icon at the top of the toolbox. This perspective correction fixes the perspective issue by making the sides of the building appear parallel.
Rotating an Image in Elements
Click and drag down on one of the corners of the bounding box (see Figure 9.12). Press and hold the Shift key, then click on a corner of the bounding box and drag with the mouse (see Figure 9.14).
Unlimited Transformations in Elements
Press and hold Alt+Shift to adjust the entire image symmetrically (see Figure 9.15). Use this command to distort the image freehand by dragging a corner (see Figure 9.16). This command is often used to place images on objects other than textures.
Editing with iPhoto
Working with the Print Dialog Box in iPhoto
Click the down arrow next to Presets to force the printer to print on photo paper at a higher resolution (see Figure 9.20). Always preview your image by clicking Preview in the Print dialog box (see Figure 9.24).
Introduction to Selection Tools
The first time you open a JPEG file, you must e.g. save it with a new name as a TIFF or PSD file to preserve the original and prevent further compression of the image. Make a duplicate of the file so that the original file remains intact by choosing File, Save As (give the new file its own name).
Toolbox Options
Try some of the procedures shown on the following pages, or experiment yourself.
Fly-Out Menus
The Most Popular Selection Tools
Lasso tools. Click and drag the Lasso tools to outline items and draw shapes freehand (see Figure 10.8). Then choose Image, Adjust, Levels or Image, Adjust, Curves to lighten or darken the selection, the equivalent of dodging or burning (see Figure 10.10).
Using the Magic Wand Tool
A low tolerance setting (such as 10) will only select pixels that are almost exactly the same in brightness and color as the pixel you're clicking on; a high tolerance setting (120) will allow more pixels in the selection (see Figure 10.12). To select an unrelated area of similar color and brightness, highlight the icon for Add to existing selection in the tool options bar and click the Magic Wand again.
Using the Lasso Tool
To select an item in a photo with a plain background (if your image has one), use the Magic Wand to select areas of the plain-colored background, then choose Select, Inverse, which will select the item. Choose Select, Inverse if you want to disable the object and change the background.
Using the Rectangular Marquee Tool
To add more, click the Add symbol in the Tool Options bar and outline the additional area. You can also press and hold the Shift key to add to an existing selection.
Using the Elliptical Marquee Tool
Introduction to Image Editing
Move the white slider to the left until the light tones on the screen look correct. The black slider will also clip all pixels to the left of it (all pixels will turn black).
Color Balance 101
Photoshop Elements includes Magnetic Lasso, which performs a similar function depending on the sensitivity you set in the Options toolbar. In the last chapter, you were introduced to the most common selection tools in Photoshop through a short exercise.
The Polygonal Lasso Tool
Magnetic Lasso
Edge Contrast tells the Magnetic Lasso tool how much contrast there should be between the subject and the background. If the Magnetic Lasso sets too many points, enter a smaller number in this field.
Single Row and Single Column Marquees
Quick Mask Mode
The Amazingly Versatile Pen Tools
When you release the mouse, the path changes to straight polygonal lines that mimic the freehand path you just drew (see Figure 11.12). Then they add anchor points to refine the rough paths created with a few lines (see Figure 11.13).
Saving Selections
When Your Software Tools Quit Working
The Power of the Color Range Command
For example, if the lightest pixels in an image are selected by Color Range and then you choose Adjust, Hue/Saturation, the saturation of the highlights will be changed a lot, the saturation of the midtones a little, and the shadow saturation will be unchanged ( see Figure 11.16). If you want to add a Color Range selection outside of an existing selection, hold down the Shift key while selecting the Color Range command.
Modifying Selections
Feather softens selection areas by blending the specified number of pixels with the area outside the selection. You can temporarily hide the marquee by choosing View, Show, Margins, or just pressing Ctrl+H (xH for Mac).
Feathering and Antialiased Selections
This is useful when you need to compare the selection to the surrounding area while making changes. In some cases, the selection bar can be a distraction, and you may prefer to work without it.
Don’t Forget the Crop Tool
Press and hold the space bar and move the mouse to see how the selection works. If you need to return to the image later and are not done yet, you can save the selection.
Understanding Different Terms for Resolution
So Cynthia asks Sarah to just print out the pictures and bring them to her house. The images were fine, but Sarah used the wrong resolution twice: online and in print.
Input Resolution
Digital Cameras and Resolution
To print it you need to change the resolution from 72 ppi to something usable on your printer, say 300 ppi. The size difference of CCD sensors versus film actually leads to other annoyances such as the "focal length multiplier". With digital SLRs (single-lens reflex cameras), the focal length of a lens must be multiplied by a number to determine the actual focal length.
Resolution of Film: How Many Pixels?
A professional photographer with a disposable camera will be able to take photos that are indistinguishable from a top-of-the-line 6-megapixel camera. An amateur with a 14-megapixel camera will make the same mistakes as with a disposable camera.
Scanner Software and Resolution
The higher the bit depth, the more tonal values will be available in the image. You may need to resample the image (explained in the "Digital Methods for Increasing Resolution" section).
Understanding Bit Depth
This increase in bit depth allows more brightness and color levels to be captured for each sample in a scanned image. This dramatic increase in sensitivity enables the scanner to capture subtle shadow detail in the darker areas of an image.
How Can a 48-Bit Scan Help Me?
A low-bit scan, which contains less information than a 48-bit scan, is further compressed by any changes to Levels or Curves. The result is gaps that appear as bristles in the resulting histogram of the image (see Figure 12-5).
Drawbacks to 48-Bit Images
You can't use adjustment layers on 48-bit images because Adobe wants you to make your tonal corrections with curves or levels and then convert the image to 24-bit. You really don't need to work with every image at 48-bit depth; with only the most important images in your collection.
Output Resolution
Save the new 24-bit image to the hard drive with a new name, and then delete the 48-bit mass file, or burn it to a CD/DVD-RW as a backup. After going through (actually, sleeping through) a 48-bit scan, you'll see why this feature only applies to your most important images.
Digital Methods for Increasing Resolution
For this reason, you should use levels or curves (or both) to adjust and then convert the file to 8-bits-per-bit. channel using Image, Mode, 8 Bits/Channel. When you are satisfied with the appearance of the image, convert to 24-bit using Image, Mode, 8 Bits/Channel.
