SLR-Single Lens Reflex – i.e. one-objective mirror.
Not especially pressing in technical details – difference of these cameras from going below that you look at object of shooting through an objective of the camera. The Parts of the world are reflected in the case of the camera from inclined a costing mirror and transferred in the view-finder of the camera (thus you see that the camera “sees”), at shooting the mirror rises, opening access of light to a shutter of the camera and a film. Optics (objective), as a rule, replaceable. It enables to adapt the chamber for any kind of shootings. More in detail about that what there are objectives. Not replaceable optics have only small group 35¼¼ the mirror cameras which are let out by firm Olimpus-IS–100/200 and IS-3000. Usually mirror camera gives greater of opportunities for the creative approach.
In turn mirror cameras share on some kinds:
1. These are mechanical cameras
These cameras assume manual operations such as: translation on following the staff, manual adjustment for sharpness, manual installation of endurance and a diaphragm. These cameras in the big honour at professional photographers. Photographing by such cameras assumes presence of the certain skills and experience. The most known mechanical cameras: NIKON F3, NIKON FM2, Minolta X–370/x-9, Minolta X-700, Pentax K-1000, Pentax P30t. Some cameras are completely mechanical and do not depend on the power supply, the some people are considered electromechanical as possess operated electronic shutter.
2. Autofocus cameras
As a rule completely automatic cameras. Their nomenclature is huge. Have system of an auto focus: the special device allowing to define distance up to removed object and in appropriate way to adjust an objective. The distance up to object is calculated on contrast. Speaking easier the auto focus in the mirror cameras is arranged as follows: on frequent strips from a photosensitive material (a matrix of an auto focus) the image which has been last through an objective gets. If object not in focus – the image is washed away – next “strips” are shined almost equally; if object in focus – the image precise – the difference of illumination of the next strips is significant. The microprocessor of the camera analyzes the received information and adjusts an objective before reception of the contrast image, the objective informs the camera distance up to object, the device calculates necessary parameters of shooting.
Autofocus cameras share in the class as on two groups
1. Cameras with replaceable optics (you can put any objective which approaches for your camera. For example MACRO for shooting fine subjects the, TELE for shooting removed objects, WIDE for shooting the nature).
2. Cameras with the built in objective (you can change parameters of an objective only by application of special adapters) to concern. To these cameras first of all known series IS of firm Olimpus. For example IS–100/200 or IS-3000 the Successful combination of quality and opportunities of the mirror camera to carelessness of “soap trays”.
Not mirror cameras
You see object of shooting through the special view-finder, not dependent on an objective, the scale of the image and border of the staff in such cameras usually coincide with real, but there is the phenomenon of a parallax (displacement) connected with some distance between an optical axis of the view-finder and an objective. Also it is impossible to supervise such parameters as depth of sharpness or accuracy of focusing that brings the certain uncertainty in end results. In chambers about a zoom the scale of the image in the view-finder is coordinated by an objective with a current focal length of an objective
Not mirror cameras are subdivided on:
1. Cameras with the built in (not replaceable) objective. Such cameras the overwhelming majority. This type of cameras usually strongly limits opportunities of management in parameters of an exposition. During too time compact cameras possess small dimensions, and qualitative models provide quality, compared with quality of mirror chambers.
2. Range-finder cameras (usually replaceable optics). Good range-finder cameras allow to operate parameters of an exposition. Due to absence of a mirror (that is fair and for compact cameras) the sizes noticeably less, than at mirror chambers.