آلة الريفلكس ذات العدستين .. طريقة عمل آلة التصوير .. كتاب التصوير الضوئي

The two-lens reflex machine .. How the camera works .. The book of photography

The two-lens reflex machine

This type of machine uses two lenses, one above the other, mounted on a moving body. The upper lens on the focus glass forms an inverted right/left image in the upper section of the machine. The lower lens that forms the image on the film contains a central shutter and an eye. The two lenses have the same focal distance: the image is adjusted by a button located on the end of the machine body that moves the lens holder forward and backward. There is a folding metal cover that protects the focus glass from intrusive light and carries a magnifying glass lens for calibration.

The great advantage of the two-lens machine is that it is very compact and has a wide-angle lens. This machine was introduced in 1930 and
The current machine has become easy to use and produces square images with the same dimensions as the calibration screw on the Karar film. This means. The machine is always used vertically whether the subject is horizontal or vertical. Negative films have a large surface area to give a clear contact drawing and can be framed when enlarged. The only drawback of this two-lens machine was that the pair of lenses could not be changed, so later models of additional lenses were introduced with other additional parts such as collimators that could be removed and installed. The regular models with fixed lenses are equipped with a rotating tool that advances the film, which feeds the shutter, and can receive a prism collimator for aiming at eye height. Some are equipped with a light meter (poise meter) built into the machine and can use 24 x 36 mm (135) film.

Image and Collimator

The collimator in the two-lens machine, which has the same dimensions as the negative film, shows almost the entire image. There is a slight difference in vision because the lenses are several centimeters apart. Some models have corrected this difference by a movable frame that doubles when calibrating and adjusting the image.

(Reflex Machine with two interchangeable lenses)


This model has two pairs of interchangeable lenses with 135-105-80-65-55
and 180mm burners. The lower lens of each pair has its own shutter. The calibration is done by a bellows that connects the case to the front body and can be used for very close range shooting. Many other additional parts increase the capabilities of this machine.