INTERMEDIATE RINGS
Cameras used for amateur purposes allow such an increase in the distance between the lens and the film, that you can get close to the subject you are photographing 70-50 cm. As you get closer to the object, the distance between the lens and the focusing screen increases, to get to twice the distance on the film with a life-size image, as in the pictures "for infinity”.
in a moment, when the image on the focusing screen is equal to the size of the photographed object, we are talking about macro photography, you can also magnify the image on the focusing screen two, three or more times than the original, but then the distance between the focusing screen and the lens must also be two, three or more times longer than with the infinity setting.
To achieve such distances, we use an additional bellows lift or intermediate rings between the lens and the focusing screen. If the design of the camera does not allow it, we deal with additional lenses put on the lens, and shortening its focal length.
Almost all lenses allow focusing in the range of 50-70 cm. Meanwhile, the whole field of macro photography,
reprography, technical photos, they sometimes require approaching the object to a distance of several centimeters, to get an image of it on a large enough scale.
Drawing. Intermediate rings (Exact in Exa).
Intermediate rings are used for this (drawing), assumed (in SLR cameras with interchangeable lenses) between the camera head and the lens.
A series of three adapter rings of different sizes is usually sufficient; this way you can get an image to scale 1:1, i.e. in natural size. By combining rings or using more rings, you can get even closer to the object, obtaining on the matting screen an image sometimes several times larger than the original (see article on macro photography).
Cameras with auto iris lenses often experience difficulties when using extension tubes, because the automatics disconnected by using the ring not only does not work, but sometimes it complicates the work, not allowing the lens to be fully opened or the aperture reduced to the desired size. These difficulties are eliminated in Exakta and Exa by a special connecting device, bypassing the ring.
In any case, a series of rings or, what's even better, intermediate bellows on the rails should be part of the equipment of every photographer interested in macro photography or reprography.