Glossary of Photo Terms

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I-O

IBIS – In-Body Image Stabilization
Introduced by Minolta in 2003 IBIS is a technology that moves the sensor to compensate for camera movement instead of moving lens elements as in lens-based image stabilization. Several manufacturers have asopted this method and some models with IBIS can coordinate with stabilized lenses for even more effective compensation.

i-Contrast – Intelligent Contrast Correction
Canon term for image dynamic range enhancement technology implemented in their cameras that uses software to balance the highlight and shadow exposure to more closely represent how the human eye sees. i-Contrast applies the changes automatically as the image is recorded or in the camera afterward if you forgot to turn it on while shooting.

IF – Internal Focusing
A lens that focuses by moving smaller internal components rather than the larger, heavier front elements.

ILC – Interchangeable Lens Camera
Refers to any camera design that allows for a variety of lenses of different focal lengths and various other properties to be mounted interchangeably. The three major types are DSLR (SLR), Mirrorless and Rangefinder.

ILCE – Interchangeable Lens Camera E-mount
Successor to the Sony NEX cameras The new Alpha mirrorless cameras use this designation in their catalog model numbers.

IS – Image Stabilized
Canon term for their lens-based image-stabilization technology

ISO – International Organization of Standardization
The American Standards Association (ASA) developed a scale that all film makers could use to standardize the sensitivity of film. The ASA standard was adopted by the International Organization of Standardization and the rating was changed to ISO. Digital sensors rate their sensitivity using the ISO film standard and use standard values like ISO50, 64, 80, 100, 160, 200, 400, 800, 1600 and so on.

i-TTL – Intellegent Through The Lens
This is Nikon’s term for their advanced electronic flash technology. It allows the camera to evaluate the exposure for the flash by using a pre-flash and measuring the exposure before firing the main burst.
JPEG – Joint Photographic Experts Group -A JPEG image is a compressed bitmap image format that was developed in the early ’90s and is available as a recording option in virtually all digital cameras. Files are appended with “.jpg”.

JPEG – Joint Photographic Experts Group (.jpg)
A JPEG image is a compressed bitmap image format that was developed in the early ’90s and is available as a recording option in virtually all digital cameras.

L – AsphericaL
Designation given to the highest tier of Canon lenses that use advanced lens materials and designs to optimize image quality.

LD – Low Dispersion
A type of glass that refracts all wavelengths of light more equally than normal glass to reduce Chromatic Aberration. 

LR – Lightroom
Common forum abbreviation for Adobe’s Lightroom workflow program

M Mode – Manual Mode
Just what it sounds like. You set the shutter, aperture and ISO manually.

Macro – Close Focusing
Macro lenses are specially-designed to focus down to extremely short distances and produce a flat field of focus for copying documents and such. True macro lenses will focus close enough that the image produced on 35mm film or a full-frame sensor is life-size. In other words, if you took a 35mm slide of a dime, the image on the slide would be the same size as the dime. This is called a 1:1 macro. You’ll see a lot of zoom lenses with “macro” tacked onto their names. These lenses focus close, but seldom give more than a 1:4 ratio (the image on the film would ¼ the size of the dime). Macro lenses are usually f/2.8 and come in 50mm – 200mm fixed focal lengths. Whether 50mm or 200mm, they seldom get closer than 1:1 but the longer the lens, the farther away you can be from the subject at 1:1. This is useful for photographing small living things that get nervous as things get closer.

Matrix Metering – Automatic Multi-Pattern, Evaluative, Honeycomb
A metering mode that measures many parts of the frame and based on a set of pre-programmed evaluations, balances the exposure to give the best overall exposure to the scene. This mode performs a “best guess” based on the pattern detected by the metering and will automatically fire the flash to fill an under-exposed area or over-expose the background if the program perceives the subject (it will try to guess the subject based on the pattern) to be under-exposed. Over the years the “best guess” has evolved into a remarkably accurate process.

MB  – Megabyte
Equal to 1,048,576 bytes (closest exponent of two to one million). Used to denote the capacity of computer-related media such as memory chips or discs.

Mb    – (Mbit) Megabit
Equal to 1,000,000 bits. Most commonly used as a measure of transfer speed of binary data (Mb/s). Because capacity is measured in megabytes (8 bits x 1024 x 1024) and speed in bits, a one megabyte file would take 8.38 seconds to transfer from a camera to a computer at 1 Mb/s.

MF – Medium Format
A class of cameras that use much larger film or sensors than cameras based on 35mm film cameras. Their exceptional image quality comes at a price that mostly limits their use to businesses and working professionals. 

MF (again) – Manual focus
A camera or lens that is focused manually.
Mirrorless  – Non-SLR digital camera -Interchangeable Lens Camera that uses an electronic viewfinder that reads directly off the sensor to view what the camera sees through the lens

MFT – Micro 4/3
This is a standard developed jointly between Kodak, Olympus, Panasonic and through Panasonic, Leica in 2008 to provide a designed-for-digital format that would allow for compact, fully-functional DSLRs that uses a defined sensor size and could interchange lenses between manufacturers via a standard mount. The name comes from the agreed-upon standard sensor’s aspect ratio that is 4:3 which is similar to most P&S cameras rather than a typical DSLR which has a 3:2 aspect like 35mm film. This format replaced the short-lived Four Thirds format from 2006 which used the same mount but used a DSLR mirror boxinstead of live-view on the LCD or an EVF for composing.

Micro-Adjust – AF Micro-Adjust
DSLR Camera setting to compensate for small errors between the phase-detection sensor calibration and the actual focal point on a lens that causes a small amount of front or back focus. The camera maintains a database of lenses that it has been adjusted for and loads the setting when a particular lens is attached. MIrrorless cameras aren’t susceptible to this since their autofocus sensors are on the focal plane already and don’t require calibration. Some mirrorless camera do have a micro-adjust setting if lens adapters are available to them that use reflective phase-detection technology like the Sony LA-EA4.

Micro Four Thirds – Micro 4/3, MFT
This is a standard developed jointly between Kodak, Olympus, Panasonic and through Panasonic, Leica in 2008 to provide a designed-for-digital format that would allow for compact, fully-functional DSLRs that uses a defined sensor size and could interchange lenses between manufacturers via a standard mount. The name comes from the agreed-upon standard sensor’s aspect ratio that is 4:3 which is similar to most P&S cameras rather than a typical DSLR which has a 3:2 aspect like 35mm film. This format replaced the short-lived Four Thirds format from 2006 which used the same mount but used a DSLR mirror boxinstead of live-view on the LCD or an EVF for composing.

MLU  – Mirror Lock Up
A feature on some SLRs and DSLRs that allows the reflex mirror to be locked into it’s shooting position. This feature is used in long telephoto and macro work to eliminate the vibration caused by the slap of the mirror as it flips up out of the way when the shutter is released. Many DSLRs with this feature will include MLU in the 2 second self-timer function so the mirror is flipped up and the camera waits 2 seconds before releasing the shutter to allow the vibration to die down.

NEX  – New E-mount eXperience
Sony’s Mirrorless camera series that features extremely compact bodies with large APS-C sensors. Unlike the Alpha series, they do not feature in-body stabilization and rely on lens-based stabilization in optics made for the new E-Mount.


NR – Noise Reduction
Common forum abbreviation for various technologies and processes used to reduce the effects of digital noise in images.

OOF  – Out Of Focus
Not in focus. A soft image may be soft for a number of reasons. OOF is a common reason. Also refers to areas in an image that are intentionally not in focus.

OS – Optical Stabilizer
Sigma term for their lens-based image-stabilization technology

OSS – Optical Steady Shot
Sony term for their lens-based image-stabilization technology.

OVF – Optical Viewfinder
Camera viewfinder that used lenses, either a separate assembly synchronized with the camera’s lens or directly through the main lens via a mirror. 

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