The lens aperture setting. The numbers may appear arbitrary, but they follow a mathematical sequence where each one lets through half the light of the one before. The sequence is (starting with the largest aperture) f1.0, f1.4, f2.0, f2.8, f4.0, [...]
Archive for the 'F' Category
Face detection is undeniably clever. Born out of the slightly creepy biometrics industry, it’s way of identifying the characteristic shapes of the human face in an image. The camera can then set the focus and exposure to reproduce these faces [...]
‘Feathering’ is where you soften the edges of selections so that you don’t get a hard division between the adjusted part of the image and the rest.
Digital cameras save images in the JPEG format or, with more advanced models, a RAW file format that preserves the full image data for conversion later on. Some models can also produce TIFF files, which are larger than JPEGs because they’re [...]
Digital cameras use their own file numbering systems for saved images, but you may well want to change the filenames according to your own system. Be wary of using purely descriptive names because as your photo collection grows you’re in [...]
The storage space taken up by the file or its size in megapixels. The file size of a digital image is important because it governs how many shots you can save on your camera’s memory card. JPEG files are smaller [...]
This is using flash with backlit subjects to lighten the side facing you, which would otherwise be in shadow. It’s often used in bright sunlight where the sun is casting ugly shadows. Due to the limited power of built-in flashguns, [...]
Fill light tools in software lighten the darker areas of images without affecting the midtones or highlights. They use different techniques for doing this, either shifting the darker tones upwards in the brightness scale or using selective masking techniques to lighten [...]
Traditional photographic film comes in a variety of forms and formats. Negative film is used to produce prints and may be colour negative film (used for snapshots and commercial portraiture, for example) or black and white negative film (used for [...]
A scanner designed for film only and not prints or documents. A good 35mm film scanner will typically cost around £500, several times more than a good flatbed scanner. A film scanner, though, will get every ounce of definition out [...]
Filters are used on the front of the camera lens to change the appearance of the photograph. It’s true that today it’s possible to simulate many filter effects using a program like Photoshop and to add many more, but there [...]
Filters are tools and special effects usually provided as ‘plug-ins’, which are like mini-applications which work within programs like Photoshop. Photoshop comes with many filter plug-ins as standard, but it’s also possible to download and install third-party plug-ins for specific tasks.
Interface used by digital camcorders and Mac computers. An alternative to the USB interface that’s used extensively by Apple computers and some more high-end peripherals like professional scanners and cameras. Firewire is much faster than USB 1.1, though the later [...]
Cameras contain hardware (the lens, shutter, sensor and so on), and ‘firmware’ (which controls the image processing, AF and other ‘logical’ or data functions). The firmware is essentially software stored within the camera’s circuitry. It’s common for camera makers to [...]
A fisheye is an extreme wideangle lens that no longer attempts to render straight lines as straight. Instead, they appear as curves which are more pronounced away from the centre of the frame. This distortion effect means that fisheyes are [...]
Image defect caused by shooting into the light. Flare shows up either as dots or ‘blobs’ of brightness diagonally opposite to the sun in the frame, or as a generally loss of contrast – an over-light ‘washed-out’ effect. If the [...]
Manually adjusting the power of the flash. Modern flashguns are designed to regulate their power automatically to produce the correct flash intensity for your subject. This doesn’t always work out (depending on the subject’s distance, characteristics, ambient lighting and so [...]
Memory with no moving parts using chips, like memory cards. All memory cards use flash memory, as do memory ‘sticks’ which plug into the computer’s USB port and are used for data transfer and portable storage.
Used for connecting an external flash. If your camera has a flash sync (x-sync) socket, you can connect it to studio flash systems. If it doesn’t, you may still be able to buy a flash adaptor from the camera maker [...]
The maximum shutter speed at which you can use flash. The shutters in digital SLRs are a set of ‘blinds’ or ‘curtains’ which move quickly in front of the sensor to expose it to the image, then cover it again. These [...]
Scanners turn prints and documents into digital images. They work a bit like a photocopier – you place the item to be scanned face-down on the glass plate. The item is ‘scanned’ into a digital file by a moving head. [...]
Flickr is a free online photo-sharing site. You can use it to show your pictures to the world at large or, by changing your privacy settings, share your photos only with selected people. Photos uploaded to Flickr are tagged so [...]
Converts focal lengths on other cameras into 35mm equivalents. The sensors in digital SLRs are usually smaller than the area of 35mm film frames, so while they can often use the lenses from film cameras, the effective focal length of [...]
A measure of a lens’s magnifying power or angle of view. Zoom lenses will have a focal length range, for example 35-105mm. The angle of view will depend on the size of the film used by the camera or the [...]
Horizontal or vertical curtains in front of the sensor. Shutters control the exposure. The shutter curtains cover the camera sensor until the shutter is fired. Then the first curtain is released, uncovering the sensor and exposing it to light, and [...]
Used to form the image seen in an SLR’s viewfinder. The image passes through the lens, it’s reflected upwards by the mirror and brought to a focus on a ground glass screen mounted horizontally in the pentaprism housing on top [...]
Making the flash fire whether it’s dark or not. In full auto mode, the camera will fire the flash in low light but leave it switched off in bright light. Forced flash mode makes it fire the flash in all [...]
This is the ‘active’ colour in Photoshop for painting, filling selections and so on. It’s set using the colour swatches at the bottom of the Tools palette. Clicking on this displays the Color Picker, but you can also set the foreground [...]
Erase the data on a memory card to make it ‘blank’. Normally, once you’ve transferred all the images from your camera’s memory card to your computer, you might simply use the camera’s ‘delete all’ command (or equivalent) to delete them [...]
Four Thirds is sensor and lens system developed by Olympus and Panasonic. The Four Thirds sensor is physically slightly smaller than the APS-C sized sensors in most digital SLRs, but the image quality is similar. The name comes partly from [...]
This is a unique three-layer sensor design used by Sigma in its SD14 digital SLR and DP1 and DP2 compacts. The Foveon sensor doesn’t organise red, green and blue pixels in a mosaic on a single layer. Instead, it copies [...]
How fast a camera can shoot continuously, in ‘frames per second’. A basic digital SLR might be able to shoot at 3 frames per second (fps) while a professional model might manage 8fps or even 10fps.
Normally, ‘frame rate’ describes the numbers of frames per second in movie footable. Sometimes, though, it’s also used to describe the continuous shooting speed of a stills camera. In practice, people use ‘frame rate’ and ‘fps’ interchangeably.
The Freehand Lasso is the most basic of Photoshop’s selection tools. You use it to outline the object or area you want to select by hand. It requires patience and care and even then it’s difficult to follow outlines with [...]
Digital SLR whose sensor is the same size as 35mm film. The majority of digital SLRs use a sensor that’s smaller than a 35mm film frame and closer to the size of an APS frame (which is why they’re sometimes [...]