Digital Photography
Glossary - Definitions of Terms
Pixel - "Picture Element" - the smallest dot of a picture. In color photographs, consists of three smaller dots (or stripes) one each of red, green and blue.
Aspect Ratio - The ratio of the width of a picture to its height. It is the width divided by the height. Most computer screens and most digital cameras use the ratio: 4:3 meaning that the picture is 4 units wide by 3 units tall. Common screen and camera ratios are:
640 x 480 (640 pixels wide by 480 pixels tall)
800 x 600 (average PC Screen resolution)
1024 x 768 (1 megapixel)
1200 x 900
1600 x 1200 (2.1 megapixel)
2048 x 1536 (3.3 megapixel)
Digital Film - Not film at all, but RAM in a small package that fits into the camera. This "film" is erasable, so that once the pictures are downloaded to computer, it may be erased and used many times. There are many formats for "digital film." Here are some of the more common:
Compact Flash RAM
Smart Media
Secure Digital RAM
Memory Stick
USB Port - Universal Serial Bus. This is a port on the back (or maybe front) of your computer that allows the connection of other USB devices. Most digital cameras use the USB port to transfer pictures from the camera to the computer. Most external memory readers use the USB port as well. Many other devices such as scanners, printers, and web-cameras use the USB connection. It is quite possible to run out of USB ports on your computer, as most have only two. One can purchase a USB "hub" for about $20. which increases the number of ports.
Most digital cameras come with a USB cable to attach the camera to the computer. They invariably include software to enable this connection, and to facilitate downloading and manipulating photos. Sometimes this software is very good, but it is often very limited. Thus the best use may be to download the photos to a known location on your computer so that they may be edited with a better photo program.
Cradle - Some cameras come with a device that attaches to the USB port and sits near your computer, ready to accept the camera, which fits neatly on it. The camera has connectors on the bottom which match up with the cradle's connectors to do three things: recharge the battery, download your photos, and to use the camera as a web-cam for video conferencing, etc. At this point, only a few Kodak and Hewlett-Packard cameras use the cradle approach.
SanDisk - Trade name for a brand of memory card readers. The SanDisk brand is so well known that many other brands are incorrectly being called by this name. This is much like the "Crescent wrench" which was originally made by the Crescent Tool Company, or the "Vise-Grip."
Memory Card Reader - A device for reading the memory card from your camera into the computer. This device usually connects to the USB port and sits on or near your computer. To download your pictures, you remove the memory card from your camera and insert into the card reader. Windows recognizes the card reader as a disk drive, allowing you to use Windows Explorer, My Computer, or the software that came with your camera to download photos from the memory card to your computer. You may also erase the memory card as if it were a disk drive, to prepare it for another round of picture-taking.
Memory card readers are fairly inexpensive nowdays, ranging from $10.00 to $30.00. Most will read only one format (compact flash, smart media, memory stick, etc.) but some have more than one slot and can read multiple types. Make sure you get one that can read the type of memory your camera uses.
Some USB printers, scanners, and combination printer/scanner devices have built-in memory card reader ports. There is even a USB mouse that has a memory card reader built in.
Photo-Editor - This is a program with allows one to make changes to photographs. At the very least, it should allow one to rotate, crop, resize, brighten/darken, and perform red-eye reduction. Most will do much more, but these are the essentials.
Some of the better-known photo-editors are:
Adobe Photoshop - the professional program. If you are editing photos for a living, you need Photoshop. It costs about $600.
Adobe Photoshop Elements - a limited version of PhotoShop. It doesn't have all the bells and whistles, but it has enough for most purposes and costs about $100.
Paint Shop Pro - from JASC software - an outstanding shareware photo editor. It is comparable to PhotoShop Elements in performance and price, and perhaps easier to learn. You may download and use it for 30 days free of charge, after which you will need to register and pay for it in order to continue using it.
Microsoft Photo-Editor - Often supplied with Microsoft Office, this is a fairly good basic photo editor. Not nearly as extensive as Paint Shop or PhotoShop, but adequate for most purposes.
Corel Photo-Paint - another editor from Corel Corporation. It is good, but I haven't used it enough to make serious comparisons with the others.
IrfanView - Actually intended to be a picture viewer/reviewer, but has substantial editing capabilities. It is freeware, available for no charge, and worth many times the cost! IrfanView performs batch conversions, allowing one to resize many pictures all at once, will create contact-sheet style webpages including small versions of your photos which automatically link to the larger version, and has several other outstanding features. It is a good addition to your primary photo editor.
Gamma Correct
Technically, gamma correction is intended to compensate for the difference between the way a camera takes in light and the way a computer screen displays it. On the average, the screen will tend to show bright colors darker than what the camera takes in. In practice, gamma correct is a good way to brighten dark pictures, or to darken washed-out photos. It often does a better job than using the "brightness" control, as it doesn't wash out the colors as much. Some washout occurs anyway, but increasing the contrast may compensate for this somewhat.
Brightness
Pretty much what it sounds like - this increases or decreases the luminance of a photo or selected area by whatever amount you specify. 0 means no change. A positive number is the percentage by which brightness will be increased, a negative number the percentage by which it will be decreased.
Contrast
Increases or decreases the difference between bright and dark areas. Less contrast gives a flatter picture, more a deeper one. It is good for salvaging a photo that is "washed out." Experiment, and remember the Undo feature!
Compression
Reduces the number of bytes in a JPEG picture file, without changing its actual size. Picture quality is reduced, but at moderate compression levels the difference is not obvious. This allows the picture files to transfer more quickly through the Internet, and so is concern to web designers, and those who send pictures through e-mail.
Compression also allows more pictures to be stored on your camera's memory card. Most digital camera have a "Picture Quality" control, which is the same as compression. If you select a lower quality level, your camera card will hold more pictures. But they won't look as good. Sorry. That's the breaks. Make your choice, high quality or more pictures. Or break down and buy another memory card! You can have more than one, you know.
Examples, Three ways to reduce a picture:
 |
+ Compression = (this is 80% compression, |
 |
Same picture size, smaller file size, lower quality |
|
+ Resize = |  |
Smaller picture, smaller file size, same quality |
|
+ Crop = |  |
Smaller picture, Smaller file size, same quality, eliminates undesired object. |
Compression: higher number is lower quality
Quality: higher number is higher quality.
Resize
.jpg
.gif
.bmp
.psp
.cdw
.....
Ulead
Website:https://jamesyawn.com/photo/index.html
Purpose of course:
To develop an understanding of the tools of digital photography,
advantages, disadvantages, and how to do things with it.
Topics:
I.Buying a camera
II.Taking pictures
III.Getting them into the computer
IV.Doing things to them
V.Doing things with them
You will need:
Yourself!
Your glasses, if you wear them,
A playful, inquisitive attitude!
Bring your digital camera if you already have one
Why digital?
After initial investment, digital photography is cheap
- no film cost
- no processing cost
- allows lots of experimentation
-results are available quickly
- most cameras offer immediate preview
- download to computer in a few minutes
- print directly to some printers, no computer needed
- digital photos are easily manipulated (improved?)
- photos are (often almost) ready for e-mail or the Web.
Why not digital?
- Cameras are expensive compared to film
- Digital Cameras EAT BATTERIES
- Lower picture quality than film
- Lenses, attachments, and other devices not readily adaptable
- Slower response, hard to get action shots
- Scanners can digitize film photos
Some even read slides or negatives!
- If you print, costs may not be much lower than conventional photos
Buying a camera, questions to ask:
- What is its resolution?
- What kind of lens does it have?
- What kind of memory?
- How does it connect to the computer?
- What kind of batteries does it use?
- What software is supplied?
- What are its “Native” file types?
JPEG?
TIFF?
Proprietary?
Kinds of batteries
AA alkaline
Alkaline rechargeable
NiCad rechargeable
Nickel-Metal-Hydride NiMH
Lithium-Ion
Camera Characteristics:
Price ranges
Less than $100: Cheap, toyish, but may be crudely functional
$300 or so – Can buy a good basic camera for informal purposes
$500to $1000 – Semi-professional cameras, better lenses, higher resolution, more features
$1500 to $5000 or more – Digital SLRs, near-professional level
Resolution
320/200 – inadequate for serious purposes.
640/480 – adequate for e-mail and web shots, not adequate for printing
1 megapixel – more than adequate for web/email, OK for informal printing
2 megapixel or higher – adequate for print publications, near professional
(Computer Screen has 4:3 ratio of height to width.)
Camera Size:
Miniature, Pocket-sized, Larger, Professional
Lenses
Cheapest cameras often have plastic lenses and have NO zoom
Optical zoom – good!
Digital zoom – not so good.Better than no zoom at all but not much.
Connectivitiy
Serial port – slow!
USB port – Ususally requires Windows 98 or newer
SanDisk or similar memory card reader
Printer or scanner with card reader
Connect camera directly to TV/VCR
Floppy disk adapter for SmartMedia
Camera “cradle”
Infrared connection
Types of digital “film” – these are the most common types, but there are others
Memory stick (Sony)
Smart Media
Compact Flash RAM
Compact Flash hard drive
Floppy Disk
CD-Writable/Rewritable
Permanent storage
Floppy disk – doesn’t hold much, not very reliable for long-term storage
Hard drive – OK for storage, but your drive will fill up!
Zip Drive – holds a good amount, fairly reliable, disks are expensive
CD- Rewritable – OK, but less reliable and more expensive than CD-Writable
CD-Writable – Highly recommended.Cheap, reliable, holds a lot
Image Processing/editing
Software included with camera, common programs:
Adobe PhotoDeluxe
Adobe PhotoShop Elements
Kodak PhotoEnhancer
Corel Draw, Photo-Paint
MGI PhotoSuite
There are many, many others
Kai’s Super Goo – fun video effects
Professional software, rarely included with camera:
Adobe Photoshop
Paint Shop Pro
Corel Photo-Paint
Recommended Shareware/Freeware
Paint Shop Pro
GIMP
Irfanview
Sources for Shareware/Freeware:
Printing
Most inkjet printers do a good job.
Use paper appropriate to the quality you wish, glossy photo paper is best.
Taking photos
Be aware of:
qComposition
qLight
qMotion
qFocus
Composition:
What is the purpose of this picture?
Document and event
Describe an object or setting
Persuade or sell
Convey a feeling
Illustrate a process
Where will this picture go?
Electronic
qE-mail
qWebshots qComputer Desktop qWeb Page qSlide Show qPresentation qScreen Saver qPhoto-tutorial |
qPhoto Album
qTee-Shirt qRefrigerator magner qCoffee Mug qWord Processing Document qNewsletter qNewspaper qMagazine qBook |
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In general, use Landscape for Electronic photos – it fits the screen better.
Composition:Rule of thirds
Place subject of photo 1/3 of the way from left or right side, or 1/3 from top or bottom edge.
 |
This often yields a more interesting composition
Also think in thirds for depth – have:
qsomething in foreground,
qsubject in mid-ground,
qsomething in background.
Light:Quality, intensity and direction
Light:Quality
Natural daylight is best
Incandescent light is OK if bright enough
Flourescent light is worst, use flash
Light:Direction
Frontal light – good for exposition but may create “flat” subject
Overhead light – may make for good landscapes, odd shadows on faces
Oblique light – may make for dramatic light/shadow scenes
Backlight – may make subject too dark
Diffuse light – good for overall exposition, “soft” shadows
Light:Fill-in Flash
When subject is backlighted, force camera to flash to light it up.
Both background and subject will be lighted.
Composition: Be aware of every object in the viewfinder
If you don’t like something, remove it!
qClean up litter
qFind a different viewpoint
qWait until undesired object moves
q(erase it later with photo-editor)
Composition:Motion
Avoiding it:
qHold the camera steady until after the shot is taken “follow-through”
qUse image stabilization, if available
Catching it:
qSelect a fast shutter-speed, or shutter-priority mode.
qTo have a moving subject clear, move the camera to keep up.Background will be blurred.
qTo have background clear, keep camera steady.Moving subject will show motion-blur.
Composition:Know Thy Camera.Some terms:
AE – Automatic Exposure
ME – Manual Exposure
Modes for Automatic Exposure
AP – Aperture Priority – aperture stays where you set it, shutter speed varies to catch right amount of light
Smaller aperture – greater depth of focus
SP – Shutter Priority – shutter speed stays where you put it, aperture varies to catch enough light
Faster shutter – better motion-stopping
Spot Metering:Camera adjusts for light at a certain spot in the viewfinder.Good for lighting a specific subject.
Know thy camera:
qTake lots of pictures!Experience is the only teacher.
qRead the manual
qTalk with other users
Composition:Know Thyself!
Listen to your “inner voice”
Look for the scene that makes you go “Aah!” (or “Argh!” if that is the feeling you want to convey)
Know the rules, then break them.
JY rev. 1/29/03