AF (Auto focus) Lock

Focus Lock is used to stop auto focus operation once the subject is in focus. This allows you to focus, compose, shoot.  On most cameras you can press the shutter half way down and the focus will lock and display the focus points until you release it.  Related Terms: Servo Mode, Manual Focus

Ambient Light

 

Ambient light is the available light in the scene being photographed before you add an artificial light.

Angle of View

 

The area of a scene that a lens can cover. The focal length of the lens determines the angle of view. A wide-angle (short-focal-length) lens includes more of a scene than a standard (normal-focal-length) lens or telephoto (long-focal-length) lens. Angle of view is basically the angle at which light rays can pass through the lens to produce an image on the film.

 

Aperture or F-stop

 

The scientific explanation is F-stop = (diameter of the) aperture / focal length.  The simple explanation is how wide the opening is in the path from the front of the lens to the sensor. The lower the f-stop number the more light allowed through the lens and the less the depth of field or area in focus.

ASA

Abbreviation for American Standards Association. In conjunction with a number, e.g., ASA 400, refers to film "speed" or sensitivity. The higher the number, the more sensitive the sensor is to light. This is an archaic term and has been replaced by ISO.

Auto Exposure Bracketing

 

Auto-bracketing is a feature of some cameras where the camera will take several successive shots (usually three) with slightly different exposure settings. This can be a useful technique when you plan to use HDR(high dynamic range imaging) techniques with a photo editing program. When you use this approach you will have three photographs taken for each time you press the shutter. See: High Dynamic Range (HDR)

Backlit

 

A backlit subject is a subject where the dominate light source is behind the subject. When a subject is backlit you will likely loose detail in your subject. (See assignment flash)

 

Bracketing

Bracketing is a technique photographers use to ensure they capture an image. When bracketing an exposure, a photographer will take a number of shots of the same image with different metered exposures. Exposure Bracketing is an excellent tool when you are not sure of an exposure or you plan to use HDR techniques later. See: High Dynamic Range (HDR)

Some cameras will even take three pictures for you. This may work in some situations, but not when the subject is moving.

Burn Out/Wash Out/Blinkies

 

Burn Out is the term that photographers use to describe over exposed highlights. If your digital camera supports it, wash out is displayed on the back camera display as flashing areas of your image. (Check Highlight Display in your manual.)

If you printed your image with an ink-jet printer and then looked at the picture you would see that no ink was deposited on the paper. The term probably goes back to slide film photography. When shooting slides an over exposed area on the film would be clear, like all the emulsion had been burned away by the light.

 

Camera Angle

The camera angle refers to the positioning of the camera in relation to the subject. A camera held above a subject and shooting down towards the subject will tend to diminish the subject. This is a good technique to use when your subject is people who are perhaps larger springs. Their face up and reduces the perspective of their body size. If you shoot a low, camera angle and you shoot up towards the subject. It tends to add stature for the subject and will have the effect of giving the subject. A wider base and a smaller top.

CCD

Charged Coupled Device, a light sensitive chip used for image gathering. In their normal condition these are gray scale devices. To create color a color pattern is laid down on the sensor pixels, using RGBG color mask. (Red, Green, Blue, and Green) The extra Green is used to create contrast in the image. The CCD Pixels gather the color from the light and pass it to the shift register for storage. *

A CCD transports the charge across the chip and reads it at one corner of the array. An analog-to-digital converter (ADC) then turns each pixel's value into a digital value by measuring the amount of charge at each photosite and converting that measurement to binary form.

CMOS

CMOS (complimentary metal-oxide semiconductor) This is the newer technology which is constructed in a similar manner to computer processors. CMOS devices use several transistors at each pixel to amplify and move the charge using more traditional wires methodology. When compared to CCDs CMOS sensors are less sensitive to light but may use 1/10 of the power of a CCD.

CMYK

Cyan, Magenta, Yellow, Black;

These are the colors used when printing images and are referred to as subtractive colors because they filter the light reflecting back to the viewer. Monitors are based upon RGB and they emit light.  Thus they are using additive colors of Red Green and Blue to build the desired color.

Compression

Process of compacting digital data, images and text. Software algorithms search the raster image to build a greatly condensed (from a file storage perspective) format of the image. (See File Formats)

 

 

Color Balance

Your camera has a setting called Auto-White Balance.  AWB will look at the image and try to determine what color of light is striking the subject. You can also tell your camera what kind of lighting you have on your subject or perform a custom white balance.
(See Color Balance Page for basic explanation)

Color Saturation

You have the option of telling your camera to increase or decrease color saturation. Increasing color saturation is handy when shooting landscapes on cloudy days.

Custom White Balance

 

You can more accurately control color by selecting a user-defined white balance.

Many digital cameras have a Custom White Balance setting that is quite easy to use, though it may take a few minutes to get the hang of it. Since each procedure varies check your owner's manual.

Depth of field/focus

This is the area that is in focus.  In reality, the area in focus extends in front of and behind the point of focus. Understanding how this works can be very vital in creating great images.

 Shallow Depth of Field means that only a small portion of the picture will be in focus, and the remaining parts of the picture will be softly out-of-focus. When photographing people this helps draw attention back to the subject.

 

 There are two main ways to obtain a narrow depth of field. Purchase a 50mm f1.8 lens, and set the lens to f1.8. You should always focus on the subject's eyes, and everything else should go out of focus. This effect is greatest when working closer to the subject.

 

If you are using a point and shoot camera simply set the camera to the PORTRAIT setting for a shallow depth-of-field.  Another method is to us AV mode and select a small value.

Digital Zoom

A feature that enlarges the subject within an image to fill more of the frame; using a digital zoom reduces the resolution of an image. Since all you are doing is zooming in digitally most experienced photographers will recommend turning this feature off. The image can be zoomed in later when you can decide if the loss of quality is worth the improved view.

DPI - DOTS PER INCH

Printing term that describes the number of dots per inch laid on the print media which creates the image.

Exposure

Correct exposure is the process of recording a digital image so that you have maximum detail of your subject across the range of highlights to shadows.

When you take pictures in an automatic mode you are asking your camera to determine the correct exposure based upon an average scene. Depending upon your subject matter, you may or may not get great photographs. A single light or dark object in your photograph can confuse your camera and cost you a great image. You should consider you and your camera as a team sharing a common goal of getting great images.

Exposure Bracketing

Sometimes, on one picture, you might have some areas of underexposure (usually in the shadows) and some areas of overexposure (we call them 'highlights'). If you meter for the shadows, the highlights will be 'blown' -- i.e. way overexposed. Conversely, if you meter for the highlights, the shadows will be way underexposed and you'll lose all details there.

One solution is to use exposure bracketing. Take one picture metering for the shadows; without moving the camera (hence the use of a tripod is mandatory here), take a second picture metering for the highlights; then, take a third picture with an average metering. Load all three images into your favorite image editing software and overlay one on top of another. By carefully removing the portions of the image that are not properly exposed (or, if you prefer, by carefully combining the portions that are correctly exposed), you end up with one image with correct exposure throughout.

Fast Lens

A fast lens is a lens with a very wide aperture capability. When you look at a lens and see that it has a minimum aperture value of f4 or less is would be considered a faster lens.

Filter

This usually refers to a piece of glass or other material that is placed in front of the lens to modify the scene before the light passes through the lens. Common filters used are polarizing filters and neutral density filters. Some cameras and editing programs also have filters which are designed to emulate the same effect by using a mathematical formula.

Fill Flash

Fill flash is a photographic technique used to brighten shadow areas. The technique is useful any time the background is significantly brighter than the subject of the photograph, particularly in backlit subjects. To use fill flash, the aperture and shutter speed are adjusted to correctly expose the background, and the flash is fired to lighten the foreground.

Flash Sync Speed

SLR cameras have a maximum shutter speed. They can use when the electronic flash is turned on. For many cameras, this is 1/200 of a second. This can be a problem when working outside trying to use fill flash techniques. Photographers often use a neutral density filter is a way to reduce the ambient light of the scene so that they can then use their flash within the acceptable range of their camera.

Focal length

In non-engineers terms the Focal Length of a lens determines its angle of view or how much can your camera see. The end result is how much the subject will be magnified for a given photographic position.

The Focal length also helps determine the perspective of an image. Longer focal lengths require shorter exposure times to minimize blurring caused by camera or subject movement and will tend to compress an image.

Formatting

Completely erasing and resetting a camera's memory card. This is recommended on a periodic basis to refresh your media cards storage system. Formatting just wipes the index to the card. The files are actually still on the card and are accessible with special software. Cameras that offer a Low Level Format will actually wipe the card.

Focusing

Adjusting a camera's lens system to bring the subject into sharp view.

Focus lock

This camera feature allows you to make sure that your subject is in focus and then locking that focus so you can re-compose.

GIF

Graphics Interchange Format; a compressed image format. GIF was the first commonly used image format on the Web, but it has been largely replaced by JPEG.

Gigabyte (GB)

A unit of data equal to 1,024 megabytes.

 

High Dynamic Range Imaging(HDR)

 

High dynamic range imaging is a set of techniques that allow a greater range of brightness between the lightest and darkest areas of an image than you can capture with a single exposure. This wider range allows HDR images to more accurately represent the wide range of intensity levels found in your photographs. It can be used in scenes of all kinds from daylight to nighttime.

Highlights

 

Highlights refer to the brightest parts of your picture. When highlights are overexposed there is no data recorded in that part of the image. Based upon camera settings, you will see those areas as blinking.

 

JAGGIES

A street term for the stair-stepped appearance of a curved or angled line in the digital imaging process. The smaller the pixels, and the greater their number the fewer "jaggies" you will see. This is also called pixelization.

JPG or JPEG

This is the most common file format for the web.  JPG is a compressed format which means that you can lose picture quality when you save it.  It is sometime called lossy compression because it throws away image data to shrink a file.  Be very careful when saving pictures in this format.  (For a more involved discussion check out ForPhotography File Formats)

ISO Film Speed

 

This is the setting of sensitivity to light. Actually the camera does not become more sensitive. It amplifies the light that it sees. This is why the higher the ISO value the more noise you will see in the picture.

Lens Flare

Lens flare is typically seen in photographs as several star bursts, rings, or spheres. Lens flare is caused by the scattering and internal reflection of bright light source in the camera lens. It is most prominent when pointing the lens at or allowing a bright point source of light to strike the front of the lens. Lens flare patterns will angle across the photograph. If you want to avoid lens flare you should purchase a lens shade.

 

Mirror Lockup

Some cameras have the ability to lock the internal mirror in the up position. This can be very handy when you are shooting a lower shutter speed and want to reduce camera shake.

Optical zoom

As opposed to digital zoom an optical zooms changes the magnification of your subject using optics. This is generally considered to be sharper than Digital Zoom.

Panning

Panning is the process where you lock focus on your subject and follow it in the viewfinder. This is a way to take great action shots where the subject is sharp and the background is blurred. This preserves the look of action in your photography.

Photography

Photography derives from the words writing with light. A photo depends upon exposure of a light sensitive material.  That material can be film or a light sensitive sensor.

PICT

The native bitmapped file format for Macintosh&153; images.

PICT2

The native color bitmapped image format for Macintosh&153;, up to 32 bit color.

Pixel

The pixel is the smallest part of a digitized or Digital Image. This is used in measuring image size and resolution.

Pixelation

The stair-stepped appearance of a curved or angled line in digital imaging. The smaller the pixels, and the greater their number, the less apparent the "pixelization" of the image. Also known as the "jaggies".

Polarizing Filter

Polarizing filters can be used to darken skies by increasing contrast between the clouds and the sky and giving them a more dramatic look.  In color photographs you will all see more saturated colors in your images. Polarizers are often used to remove reflections from the water, cars, or other outdoor shiny objects. The downside to these lens is that they will reduce the amount of light passing through the lens. You may need to increase your ISO or use a tripod to compensate.

PPI/DPI

PPI and DPI are often used interchangeably.  Technically, that is incorrect.  DPI stands for Dots Per Inch and PPI stands for Pixels Per Inch.  A pixel is a digital point of light.

Prime Lens

A prime lens is a non-zooming lens and will have a fixed focal length.

Raw Format

RAW file format is the un-compressed and unprocessed data as it was captured by the camera's image sensor. For former film photographers this format allows them to shoot more like they did with film. The end result is a file where you can change many camera settings while looking at the image on the computer. Warning: Proper exposure is still a must. Don't rely on the extra flexibility and get lazy.

Resolution

Think of this as how much information about the picture the camera records.  My recommendation is to always shoot at the highest resolution.  Resolution refers to how many dots, or pixels, are in a given amount of space. The higher an image’s resolution, meaning the more dots there are in the same amount of space, the less pixilation will occur, and the better the image will appear. Another way to understand this is to say that the more information that’s packed into an image, the smoother its appearance.

The resolution of an image on your computer screen is often measured by PPI (pixels per inch). A printed image’s resolution is often measured by DPI (dots per inch). An image that is 72dpi contains less information than one that is 300dpi. Images seen on a computer screen are usually 72 PPI, because 72ppi is what most monitors display, but 300dpi is the “industry standard” for photo quality printing. This leads us to the two different levels of resolution that a designer uses; screen resolution and print resolution.

Saturation

Saturation refers to the intensity of the color in an image. Increasing saturation VA your camera's menu system is an excellent way to give more color to the scene on a cloudy day.

Shadows

Shadows refers to the darker parts of your scene. When looking at the histogram shadows are depicted on the left-hand side of the histogram.

Shutter Lag

One of the major problems many people have with their digital cameras and action is shutter lag. On some digital cameras, it may take an entire second from when the shutter button is pressed before the photo is taken. A traditional film camera would have a lag of between 1 second and 50 milliseconds.

 

What this means is that the photographer must compensate for shutter lag when shooting action shots. Understanding this lag means allowing some lead time between when you want to take the photograph and when you depress the shutter button. Getting this timing right will make the difference between a photograph of "Oh WOW!" vs. "Oh Shucks".

Shutter speed

All cameras have a shutter speed. It may be fixed, or adjustable, or automatic.  The shutter speed is how long the light sensitive material is exposed to the light.

JPG

This is the most common file format for the web.  JPG is a compressed format which means that you can lose picture quality when you save it.  It is sometime called lossy compression because it throws away image data to shrink a file.  Be very careful when saving pictures in this format.  (For a more involved discussion check out ForPhotography File Formats)

 

 

White Balance

Digital cameras have the ability to adjust the color based on the lighting situation where they are used. This is known as white balance. The cameras use white as a reference and adjust the color balance to give as true as possible a white, correcting all the other colors by doing this. HP color scientists have developed a family of algorithms to automatically adjust white balance under a wide range of conditions and with remarkable accuracy.

TWAIN

Technology Without An Interesting Name; the standard interface between software applications and image-capturing devices such as scanners.

USB

Universal Serial Bus; a popular interface for connecting all sorts of external devices, including digital cameras, to most PC and Apple Macintosh computers. A USB device can be plugged in and used without restarting a computer.

Zoom, optical

– A feature that alters a camera's focal length, filling more of the frame with the subject.  Often referred to as a number like 5X optical.

Zoom lens

A lens with an adjustable focal length that lets you see a scene from a narrow to a wide field of view.

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