35mm Equivalent

(also:
Crop Factor
Focal Length Multiplier)

Anti-Blur

A camera mode that attempts to use a fast enough shutter speed (by upping the ISO) to prevent camera shake.

Using a higher ISO usually results in higher noise in your images.

Do not confuse with "anti-shake" or "image stabilization" technology where either the lens or CCD image sensor is stabilized to prevent camera shake.

Anti-Shake

(also:
Image Stabilization
Vibration Reduction)

A technology that stabilizes either the lens or image sensor to effectively reduce blur due to camera shake when using a slow shutter speed.

This allows the hand-holding of a camera at slower shutter speed (without upping the ISO).

Do not confuse with "anti-blur" or "picture stabilization" where the camera selects a higher ISO to allow the use of a fast enough shutter speed to counter the effect of camera shake.

Crop Factor

(also:
Focal Length Multiplier
35mm Equivalent)

Not to be confused with "Crop" of a picture, these terms are exclusively used in the context of relating focal length to field of view (FOV), using a full-frame sensor size (24x36mm) as a reference.

When a 35mm lens is used on a digital SLR using an image sensor that is smaller than full-frame, the smaller sensor records only a "crop" of what a full-frame sensor can, thus recording a narrower field of view.

For example, an APS-sized image sensor is about half-frame and therefore has a crop factor, or focal length multiplier, of 2x (more accurately, 1.6x).

The term focal length multiplier is commonly used because, to obtain an accurate indication of the actual field of view covered, we multiply the 35mm focal length of the lens by the crop factor (focal length multiplier) to obtain a 35mm focal length equivalent.

Technically, lenses made specifically for a smaller than full-frame image sensor has no crop factor. Thus, we don't specifically speak of a crop factor for P&S cameras.

However, because image sensors in P&S cameras come in many different sizes, the specified focal lengths of the lenses do not accurately represent the actual field of view recorded and cannot be directly compared one to another. They do not really make any sense until we can relate all of them to a standard reference. By using a full-frame sensor and the lenses made for them as our reference, we can then assign a "35mm Equivalent" focal length to each lens/sensor size combination to obtain an accurate indication of the field of view covered.

Using "35mm Equivalent" focal lengths, a 35mm-50mm lens is considered normal (35mm is a slight wide-angle, but pretty much the norm in today's P&S cameras), a 28mm or less is a wide-angle, a 100mm-200mm is a medium telephoto, a 300mm-400mm (and longer) is a long telephoto.

Focal Length Multiplier

(also:
Crop Factor
35mm Equivalent)

The image sensor is the equivalent of 'film'.

An image sensor contains millions of pixels (megapixels) arranged in a matrix whose job is to catch and record light when you take a picture. Each pixel registers the brightness -- or, intensity -- of the light falling on it. By using colored filters and an array of small lenses, the image sensor is able to record color values in a small footprint.

A high resolution image sensor (3 megapixels and up) can capture much more variation in light than a low resolution image sensor (less than 3 megapixels), and can therefore reproduce an image more faithfully and realistically.

We recommend an image sensor with a resolution of 3 effective megapixels and up .

The size of an image sensor also contributes to the quality of the images captured. In general, the larger the image sensor, the less noise in the images. So, all things equal, a 1/1.8 in. 4 megapixels image sensor will capture less noisy images than a 1/2.7 in. 4 megapixels image sensor.

Image Stabilization

(also:
Anti-Shake
Vibration Reduction)

see Anti-Shake

How the camera measures the amount of light available to expose a picture.

Centre-Weighted: Readings are taken at various part of the picture, with a special emphasis for the centre.

Spot: Readings are taken at a specific point.

Besides the above two light metering options, each camera manufacturer has its own variations, such as Matrix Metering, Multi-Pattern Metering, etc.

Megapixels, effective

Millions of pixels (usually used in reference to the resolution of an image sensor).

A digital camera can have an image sensor that is rated 4.2 megapixels but delivers an effective resolution of 4.0 megapixels. The higher the effective resolution, the higher the quality of the picture that can be recorded (providing the lens is able to produce the quality image in the first place).

Some digital cameras might advertise the "interpolated" pixels. As an example, Fujifilm's Super CCD image sensor can capture "effective" pixels of 3.1 megapixels, then its software kicks in and interpolates them up to 6 megapixels. Do bear in mind a digital camera that outputs 6 interpolated megapixels will never deliver the same quality that a real 6 effective megapixels digital camera will, and should still be compared to a 3 effective megapixels digital camera.

What is important when comparing resolution of different image sensors in digital cameras is the effective megapixels.

Original Equipment Manufacturer.

While this is not technically a digital photography term, you may have come across it when reading about how many of the major digital camera companies do not actually make the cameras bearing their brands, and wondered if one brand was any different from another.

The questionis sometimes yes and sometimes no.

The OEMs outsource the manufacture to those low-cost third party manufacturers and then rebrand the cameras, sometimes adding value in the form of better lenses and firmware and sometimes not.

Now you know why some of these digital cameras have very similar features set (especially the image sensor characteristics) and why they even look the same, minus some cosmetic changes.

When a slow shutter speed is used (1/30 sec. and lower), the image degrades due to the buildup of electronic signal ("noise"). Software in the digital camera automatically compensates to reduce that noise. What is important is a camera with noise reduction that starts at shutter speeds of 1/30 sec. and lower .

Similarly, when a high ISO is used, noise starts to show in images. For now, most consumer digital cameras are not good at high ISOs, even though the camera might offer them.

Photo graphy + Digital Pi xels

Digital Photography is a marriage of traditional photography (you still gotta develop an eye for what makes a good picture) and digital pixels, hence:

Digital Photography = Photo graphy + Digital Pi xels = Photoxels .

For our purpose, let's just define this as the number of pixels used to capture an image. In reality, excellent image resolution is achieved by a combination of pixel count (image sensor resolution) and lens resolution.

If the image sensor resolution is expressed as numbers such as 2048x1536, just multiply them out and divide by 1 million to get the resolution in megapixels. In this case, we get 3+ megapixels.

Usually the higher the image sensor resolution, the better the image quality.

The amount of control you have in choosing how your digital camera captures an image.

All digital cameras usually have an Auto mode: the camera decides for you the best shutter speed/aperture settings.

Shutter Priority: Allows you to decide the shutter speed (e.g. fast at 1/500 sec. for stop action photography, or slow at 2 sec. for night photography), and the camera decides the best aperture.

Aperture Priority: Allows you to choose the aperture (e.g. large at F1.8 for portrait, of small at F16 for landscapes).

Manual: You have complete creative control in selecting both the shutter and aperture.

Scene Modes: Pre-set exposure control (shutter/aperture combination, plus other adjustments, such as white balance, exposure compensation, etc.) for various common picture situations, such as Night Scene, Portrait, Landscape, Action, etc.

The time elapsed between pressing the shutter release button and the camera actually taking the picture.

A short shutter lag (around 1/2 sec. or less) is desirable since it allows you to take candid shots.

A long shutter lag (around 1 sec. or more) means that you will find it difficult to capture the picture at the exact moment you desire (since the camera takes it one second or more after you depressed the shutter).

Vibration Reduction

(also:
Anti-Shake
Image Stabilization)

see Anti-Shake

When a digital pictured is captured, it can be manipulated, either using a image editing software (such as Photoshop) on your computer, or right at the time of taking the picture in the digital camera. White balance refers to the ability to adjust colors based on white as a reference color to give as true a white as possible; in the process, all the other colors are also corrected. Some preset white balance settings are daylight, cloudy, tungsten, or fluorescent. Using white balance properly is essential in digital photography.

Whereas an optical zoom uses the optics (lens) of the digital camera to move you closer to your subject, a digital zoom simply uses the existing image and enlarges it digitally.

Enlarging the image digitally reduces picture quality, and should therefore usually be avoided. However, a judicious use of digital zoom may sometimes yield images that are of quite acceptable quality. So, use with caution.

Some manufacturers label their lenses with the "total zoom" by multiplying the optical with the digital. Ignore total zoom claims because you can use any multiplier digital zoom you want in an image editing software.

What is important when comparing digital cameras is the optical zoom. Digital zoom can always be achieved later in an image editing software, such as Photoshop, so should not really be a determining factor when choosing a digital camera.