Technical terms I - L


image noise

Electronic image sensors, such as those used in digital still cameras or camcorders, have an inherent noise that consists mainly of the dark noise (noise even without illumination), a shot noise (photon noise) and the receiver noises (noise of the amplifier or read-out electronics). These noise components are critically dependent on the technology and size of the pick-up sensor, the quality of the electronics and also the ambient temperature. Some of the noise can be greatly reduced by appropriate signal processing, which is now standard in high-quality cameras.


image sensor

The term image sensor has a broad meaning, being in the digital photo technology for the recording sensor, which takes the picture two-dimensionally instead of the film. In practice, this takes over a CCD or CMOS chip. As an indication of the theoretically achievable resolution of a digital camera, the pixels of the sensor are specified in megapixels.


image stabilizer

Image stabilizers are used to reduce "blurring", as they happen, for example, when shooting from the hand with long focal lengths (telephoto lenses) very fast. But they do not help with motives that move. Image stabilizers can either be part of the lens or the camera. The manufacturers of lenses or cameras each have their own name for this system. At Nikon VR, Canon IS, Sigma OS and Tamron VC to name a few.


Interchangeable lens

Interchangeable lenses are lenses that have a connection system. Through the connection system you can change the lenses. Beware, every camera manufacturer has its own system. That means lenses from Canon do not fit on Nikon and vice versa.


intermediate rings

They are only available for cameras with obligatory interchangeable lenses. These rings are screwed between the lens and the body to increase the focal length.


iris diaphragm

Opening aperture made of metal or plastic lamellae, which is continuously adjustable and whose adjustment is made with the diaphragm ring located on the lens. In this type of aperture, the slats go in and out. The problem with this panel is that the slats must be well lubricated otherwise the exposure times are not correct. Over time, this oil will resinify, reducing the speed of the iris and causing false exposure. (Over-exposure, too bright photos)


JPG or JPEG Format

Joint Photographic Expert Group. This short form refers to a compression technique for image data, which can reduce the data size by accepting quality losses up to a factor of 10. This is a widely used format and is currently the most popular compression method in digital photography.



A ground glass pane partly depending on the quality with compensation. You can find them in every lens.


lens hood

The lens hood is used to shield the recording against diffused light. This will significantly improve the contrast of the shots in most shooting situations. Depending on the manufacturer, there are different versions, but usually there is a lens hood made of black plastic and is placed in front of the lens of the camera.



As Lensbaby an interchangeable lens is called, which can be freely selected by a flexibly movable lens barrel focus area.


light meter

A light meter of a camera measures the light reflected from the object. These values are used as the basis for controlling the auto exposure mode. Formerly there were external exposure meters because the cameras had not installed. The values then had to be transferred to the camera. Of course, there are still these handheld light meters today.



Lenses from the professional line of Canon with very high quality. Often they stand out because of their white color.