SHoPP Intro to Digital Photography
Lesson 1: Photography Terms and Definitions for Digital Photography - By
understanding the terms used in digital photography, you will be able to use your camera more effectively.
Read through the following information, then read through your camera’s manual and highlight
Camera and Photographic Equipment Terms
Digital camera: a camera that captures the photograph using an electronic imaging sensor to record data in pixels on a memory card instead of on traditional film.
Digital zoom: a zoom lens that moves closer to the subject by cropping the image within the LCD screen. The drawback to a digital zoom is the loss of quality. A digital zoom is essentially no different than cropping and editing in a digital photography software program.
Optical zoom: a zoom lens that moves your view closer to the subject without losing photographic quality. It is the traditional zoom lens.
Flash card: a memory card designed for use in your camera that uses flash memory. There are several types of flash cards.
Flash memory: a memory chip that retains the data after being shut off.
Image resolution: the number of pixels in a digital photograph.
Lag time: the time that elapses between when the shutter release is pressed and the camera takes the photograph. Most digital camera models except digital SLRs experience shutter lag.
Liquid Crystal Display (LCD) screen: a viewing window that allows previewing or reviewing of images and allows camera settings to be changed.
Memory card: small card inserted into the camera, used to store images. Images are downloaded from the card, generally to a computer, and the card can then be reused.
Memory stick: a small memory card for storing photographs using flash memory.
ISO Speed: Similar to the traditional film camera rating system, ISO speed is determined by the camera's imaging sensor. As in traditional film cameras, the higher ISO, the lower the image quality.
Aperture: The camera's aperture is the hole through which light enters the camera. Apertures are measured using a relative scale, called "F numbers" such as F/4, F/5.6, F/8, F/11, etc. The smaller F-numbers refer to larger openings to let in light. The larger the aperture (smaller F number) the less time the camera needs to take a picture. For any particular light level and ISO, there is a range of "equivalent exposures" which will produce the same digitally exposed
For example, the following combinations of how long the shutter is open (shutter speed) and aperture opening (f number) will produce the same exposure:
; 1/500 at F/4
; 1/250 at F/5.6
; 1/125 at F/11
; 1/60 at F/16
Although the above settings will produce the same exposure, the results will often look
rather different. As an example, if you are photographing a moving car, 1/500 at F/4 will probably give a fairly sharp result because the aperture is only open a very short time. However, if you use the slower shutter speed of 1/60 at F/16 you will get a blurred result, since the car has moved quite a distance in 1/60th of a second.
Part of the challenge involved with digital photography training is that there are so many different digital cameras available. Since each camera uses different modes, controls, and technologies, digital photography training has to stay somewhat generic.
Many simpler cameras do not allow you to control the aperture independently. However, they may offer different "program modes," such as a "sports" or "action" program.
These programs use a very fast shutter speed, typically between 1/500 and 1/2000. Check your manual for specific details.
Aspect ratio: the width divided by the height of an image.
Byte: a unit of measure equal to 8 bits of digital information.
Dots per inch (DPI): a measurement of the resolution of a digital photograph. The higher the number the greater the resolution.
Dots per inch (dpi): a measure of the number of pixels per inch.
Histogram: a graph that shows the range of tones from dark to light in a photograph.
Image pixels: the image itself is composed of pixels in a series of rows and columns. The size of each pixel depends on the size the image is displayed. A smaller image size will have larger pixels and a larger image size will have smaller pixels.
JPEG: the most prevalent standard for compressing image data.
Megapixel: a measurement equal to one million pixels.
Pixel: the single point of a digital image that makes up a photograph. Digital photographs contain thousands or millions of pixels.
RAW image format: the digital information coming directly off the camera sensor with no in-camera processing.
Thumbnail: A small version of a photograph.
Digital Image Storage
Compact disc (CD): a read-only storage for digital media.
CD burning: the process of saving your digital file to a CD.
Compression: the process of reducing the size of a digital photograph to speed processing and transmission time and reducing file size.
Download: the process of moving computer data from one location to another such as transferring photographs from a memory card to the computer.
File: a computer document.
Hard drive: a storage device that holds the data to be accessed by the computer.
What are Megapixels?:
A camera’s megapixel rating will help you
determine the largest size of prints you can
expect to make without sacrificing the quality of
the image. It also will help you determine how
much flexibility you will have with photo-editing
software after an image has been captured.
The following guide will help you know what size
of high-quality print you can expect from each
It’s important to remember that these measurements are for professional-quality prints. You
can print any image at any size, and in many cases it is very difficult to see a significant decrease in quality as you enlarge images.
This photo was taken at three different megapixels and resulted in the following image sizes: 1.6 megapixels -- 1536 x 1024 2.8 megapixels -- 2048 x 1360 6.3 megapixels -- 3072 x 2048 When each of these is printed at 4” x 6” you will hardly notice a difference in the prints. If you print them each at 8” x 10” you will begin to see a slight difference in the quality of the 1.6
According to most photo developing services, an image that is 1600 x 1200 pixels can be printed with good results up to as large as 8” x 10”. Therefore, you can actually use a 2.0 megapixel camera and have prints made as large as 8” x 10” with very little loss of quality.
The higher the number of megapixels your camera has the more flexibility and options you will have when editing, cropping and printing your pictures. A larger original image will allow you to crop a smaller portion of the large photograph and still have a high quality print at 4” x 6” or larger (as shown below).
In the next two images (below), the same section of the photograph was taken from the 6.3 megapixel image as well as the 1.6 megapixel image. The higher megapixel image on the left does have a slightly crisper image than the lower megapixel image, but at a small print-size, it’s barely noticeable.
Choose a camera with a megapixel rating that will allow you to meet your photography needs. While it’s
probably better to buy more than you need rather than less, it’s not necessary to spend extra money on a 6.0 megapixel camera if all you require is 3.0 megapixels.
If you don’t plan to print larger than 4” x 6” and aren’t interested in cropping or editing images, a 2.0 megapixel camera is probably sufficient and will give you great prints. If you’d like more flexibility with cropping and enlarging prints to 8” x 10”, a 3.0 or 4.0 megapixel camera will give you that option. If you
want to be able to print a poster-sized print--just in case you get a photograph that turns out fantastic-- a 6.0 megapixel camera might be more what you’re looking for.
The bottom line: More megapixels equal more detail. While you can print an 8” x 10” from a 2.0
megapixel camera with good results, the same photo printed from a 3.0 or 4.0 megapixel camera will be sharper and more detailed.
What size photos will I be printing? Can I tell a difference between 2.0 and 4.0 megapixels? Are the additional detail and original image size important to me?