A Glossary of Digital Camera Terms and Definitions – Pixels and Pictures
Sharper, brighter – a better picture, a clearer image. That’s the goal of digital cameras today. And the technology they use to achieve this goal can get fairly complicated. But if you look at it in simple terms, it can become clearer. So this glossary of digital camera terms and definitions is designed to simplify some of the technical terms you’ll come across as you explore the world of digital photography. So sit down and focus.
- A/D converter
The A/D converter works with the CCD. It’s the device that actually converts the information from the CCD into digital format.
- AE (Auto Exposure)
AE automatically sets the exposure in three ways, according to the available light conditions. It uses either programmed, that automatically adjusts the aperture and shutter speed; aperture priority, that automatically adjusts the shutter speed and you adjust the aperture; or shutter priority, that automatically adjusts the aperture and you adjust the shutter speed.
- AF (Auto Focus)
The AF on a digital camera allows you to lock in the focal point by placing it in the middle of the focus “window” in the viewfinder, pressing the shutter button halfway down, then moving the camera to change the position of the focal point. This allows you to place the image you want to focus on, off to one side of the picture.
An algorithm is a mathematical process used to solve an equation. In a digital camera, an algorithm is used to determine the compression and color mix that produces an image. To properly understand algorithms, you need a degree in calculus (which we don’t have!).
The aperture is the opening in the lens that accepts the amount of light let in by the shutter and transfers it to the image sensor.
- AWB (Automatic White Balance)
AWB is an option on some digital cameras that automatically sets the brightness of the image.
The battery in a digital camera is usually a standard alkaline AA battery, but some digital cameras use rechargeable batteries.
A bit, short for binary + digit, is the smallest unit of memory in a computer. In digital cameras, it’s a term used in conjunction with digital compression.
Brightness refers to the range from light to dark in an image. Its expressed in levels of 0, which is totally black, to 255, which is totally white.
- Burst mode
Have you ever watched a professional photographer taking continuous pictures, one after the other, without seemingly stopping? That’s called burst mode and it’s done by just holding down the shutter button.
- Card reader
A card reader is a device designed to transfer images from a memory card to a computer. You can get ones that accept Compact Flash cards, or Smart Media cards, or both.
- Carrying bags
Carrying bags, sometimes called camera cases, are designed to hold your digital camera, along with all the necessary accessories, like camera lenses, filters, etc.
- CCD (charge-coupled device)
A CCD is an integral part of a digital camera. It’s actually a tiny light-sensitive computer chip that gathers image information using electrical charges and converts it, with the A/D converter, to digital format.
Chroma is made up of the combination of saturation and hue, to determine a pixel’s color.
- Color balance
Color balance refers to how close a photo resembles the real-life scene.
- Compact Flash
Compact Flash is a removable memory card designed for use in digital cameras made by Samsung, Hewlett Packard (HP), Casio and Canon.
Compression is the digital process of breaking down the analog parts of an image into smaller digital parts, so it doesn’t take up as much data space, and allows more images to be stored.
- Continuous AF
When continuous AF is activated, the autofocus is on, even when the shutter button isn’t pushed.
- DOF (depth of field)
DOF refers to the focus range, which is determined by how much the aperture is opened. A large aperture opening makes the DOF shallow, while a small opening makes it deeper.
- Digital zoom
A digital zoom makes the center half of your picture bigger by cutting off the outside. As the image gets bigger, it loses its sharpness.
- Docking station
A docking station is a device developed for use with some HP and Kodak digital cameras, that’s designed to download images from your camera to your computer. You just put your camera in the dock and push a button.
- DSLR (digital SLR)
A DSLR camera is a digital camera that allows you to change the lenses. It’s a fairly new development and is used mostly by professionals. Manufacturers of DSLRs are Canon, Fuji, Kodak, Nikon, Olympus, Pentax and Sigma.
- EXIF (Exchangeable Image File format)
EXIF is the information relevant to each picture you take, such as date/time, resolution, orientation, etc., that’s “stamped” on the image as its transferred to your computer.
Exposure refers to how much light is let into the camera, and is determined by settings of the lens aperture and shutter speed.
The flash in most digital cameras is built-in. There are several flash modes for adjustment with certain conditions. There’s Autoflash, where the flash fires automatically in low-light situations; Fill-flash, where the flash fires with each exposure regardless of the amount of ambient light; and Red-eye reduction, where multiple flashes are used before the main flash to reduce red-eye.
- Flash memory
Flash memory is the name given to the removable memory cards that record images in a digital camera. The data isn’t lost when the power’s off, and the space can be continually erased and used again. Examples of flash memory are Compact Flash, Smart Media and Memory Stick.
- Hot shoe
A hot shoe is the connector on top of the camera where a separate flash unit can be attached. It fires at the same time a built-in flash would.
The hue in a color image refers to the predominant color in that image.
- Image sensor
The image sensor is the part in a digital camera that collects the image data let in by the aperture.
InfoLITHIUM is a battery pack made by Sony that has a chip inside that tells you how many minutes you have before your battery dies, if you continue to use it at the current rate of discharge.
Interpolated images are those that have been given enlarged resolutions, using a combination of software and those complicated algorithms.
- ISO (International Standards Organization)
ISO, sometimes referred to as the speed, is a camera’s light-sensitivity. Think of the film you used to buy – it was 100, 200, 400, etc., depending on how fast the images were going to be moving when you took the picture.
- JPEG (Joint Photographic Experts Group)
JPEG was named after the committee that designed the standard image compression algorithm. It’s the system used for compressing digital images of real-life scenes, as opposed to cartoons or drawings.
- Lithium battery
Lithium batteries, or lithium ion batteries, are one kind of rechargeable battery used in digital cameras. They’re about 50% more powerful than NiMH batteries.
Macro refers to a camera lens that takes close-up pictures that record the image in it’s actual size.
A megapixel is equal to 1 millions pixels.
Digital cameras use memory to store images, rather than film. The camera has an internal memory which stores a limited number of images. Most digital cameras have a slot for a removable memory card that provides extra storage space.
- Memory cards
Memory cards provide extra storage for images. Their size ranges from 4MB to 128 MB, with a 64MB card holding about 106 photos.
- Memory Sticks
Memory Sticks are memory cards made for Sony digital cameras.
- MMC (MultiMedia cards)
MultiMedia cards are removable memory cards that can store MP3 sound files, as well as image files.
NiMH stands for Nickel-Metal Hydride, and is the name for one of the types of rechargeable batteries used in most digital cameras. Just like the new cellphone batteries, it doesn’t need to be completely discharged before being recharged.
- OEM (Original Equipment Manufacturer)
OEM refers to something that carries one company’s label, but is really manufactured by another company.
- Optical zoom
An optical zoom actually moves, allowing wide-angle, telephoto or close-up pictures. It’s the same kind of zoom that SLR film cameras use but, unlike the digital zoom, it doesn’t reduce the resolution.
- Orientation sensor
An orientation sensor is a cool option on digital cameras that can tell when you turn the camera sideways to take your picture, and adjusts the finished image accordingly.
Pixel is a word that comes from “picture elements”. It refers to the smallest element, or dot, that makes up an image. The number of pixels determines the resolution.
- PPI (pixels per inch)
PPI refers to the size of a printed picture, with a higher number meaning the picture is more detailed.
You’ve all seen red-eye on those photos you used to get back after they were developed. It’s caused by the light of the flash hitting the blood vessels at the back of the retina. The closer the flash is to the lens, the more likely this is to happen.
- Red-Eye Reduction Mode
Red-Eye Reduction Mode is a flash mode that eliminates red-eye. It fires an extra flash before the main flash that makes the pupil close before the picture is taken.
Resolution refers to the number of pixels in an image which, in turn determines its sharpness. Its expressed as horizontal pixels x vertical pixels, in a ratio of 4:3, for example, 800 x 600, 1600 x 1200, 2048 x 1536, etc.
A picture’s saturation, or density, refers to how much light is present.
- SD (Secure Digital) memory card
An SD memory card is a removable memory card used in most of the newer digital cameras. Its smaller than other memory cards, about the size of a stamp.
Remember when all photos had a brown tinge? It’s called sepia. And now you can make your photos look that way again. Some digital cameras have a sepia option that, when activated, converts the image into shades of brown.
The shutter is the part of a digital camera that opens and closes to allow light to hit the image sensor.
A telephoto lens allows you to take pictures of distant objects, and make them appear closer, but not as close as a macro lens. This is one of several digital camera lenses available as part of a zoom camera, or as a separate lens to use with an SLR camera.
A tripod is a three-legged stand designed to hold a camera steady during critical picture-taking. It can also be used in conjunction with the self-timer, if you want to get into the picture yourself.
- USB port
The USB (universal serial bus) port is the terminal in the back of the computer where you plug your digital camera or card reader. When connected, you’re ready to download your photos from your camera to your computer.
- xD Picture card
An xD Picture card is a removable memory card, about the size of a stamp, designed for use in some Olympus and Fuji digital cameras.
- Zoom lens
A zoom lens gives a combination of focal lengths, usually from 35mm-105mm. They allow you to take pictures ranging from wide angle to very close up.
So there you have it – simple, but informative. Just the type of knowledge that’ll help you make the right decision when choosing a digital camera. And don’t forgot those accessories. There’s a wonderful world of helpful items that can make your photo-taking experience much more enjoyable.
And if you really want to increase your knowledge, take what you’ve learned here, and add to it with one of the many manuals, photography books and magazines. They’ll teach you how to use your digital camera just like the professionals.
And remember, there’s a digital camera war going on out there. Look at how many companies are competing for your business: Tamron, Sigma, Kodak, Sony, Casio, Canon, Pentax, Nikon, Fuji, Ricoh, Olympus – did we leave anyone out? We may have – there are so many. So if you want to get the best camera equipment to suit your individual use, do your homework. Check out the digital camera comparisons, ratings, and reviews. You’ll find everything you need to know on the Internet.
And then you can start taking those pictures, storing your memories to relive on those rainy evenings, just like your parents used to do. Except when you do it, you’ll be sitting at your computer. Enjoy!
About The Author
Gareth Marples is a successful freelance writer providing valuable tips and advice for consumers purchasing fast multimedia digital projectors, flat projector screens and digital cameras, cases & accessories. His numerous articles offer moneysaving tips and valuable insight on typically confusing topics.
This "Glossary of Digital Camera Terms and Definitions" reprinted with permission.
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