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How is the exposure time calculated when using remote conversion means?

The installation of a teleconverter between the primary lens and the camera body diffuses the light over a wide area, thus reducing the brightness of the image. Thus the 2 x converter effectively reduces the amount of light reaching the film by about a quarter effectively reducing the luminosity by 2 E/stops and the 3 x converter reducing the luminosity by 3 stops / 4 No tolerances are required for this when the camera is equipped with an exposure time meter light is read through the lens, but this factor must be taken into account when the camera is not equipped with a TTL meter or when flash light is used, in which case the shutter should be opened to the appropriate number of stops / 4 to that specified by the exposure meter or by a guide table Exposing the film to light or a flash calculator even when the flash device is automatic, and it is not necessary to adjust the aperture position for cameras in which the exposure meter takes readings during flash exposure operations

What is the order in which the close-up lenses are mounted when two or more lenses are used?

Close-up lenses are individual convex meniscus elements that, when mounted on the front of the lens, shorten the minimum focusing distance

It has its own focal length, and these lenses are manufactured and are equipped with different refractive powers of light, alternating with their focal length estimated in meters. Thus, we find that the lens in which the average power is one includes a focal length equal to one meter. They are each mounted one way on a filter and screwed into the spiral inside the front of the lens barrel. do not need. capture lenses. Close-up means an increase in exposure and can be used either individually or in combination as the one with the most power is installed in the lens first and then the one that follows in strength. If a filter is also used, it must be installed at the front of the close-up lens, and with several additional surfaces at the front of the lens, it must be used. Lens cap. It must be ensured that the work is not interrupted or interrupted by the large number of additional accessories on the front of the lens

Can a telescope or a pair of binoculars be used as a telephoto telephoto lens?

Although photographs may be taken with a telescope or with a pair of binoculars (of appropriate length to mount the camera) now the resulting images may not be as clear as desired. This is due to the fact that optical issues related to telescopes and binoculars are designed according to purely optical requirements and not according to photographic standards and regulations. However, the effectiveness of such devices could be somewhat improved by installing an aperture disk in the front of the front element of the accessory, although this will reduce the aperture efficiency of the position calibration

Good pictures can be taken directly with a telescope or binoculars, but the accessory must be attached to the front of the camera lens and be focused on the infinity position, and the aperture position of the camera lens should be set to its maximum aperture.
To calculate exposure time on non-TTL scales, the focal length of the lens is multiplied by the magnification of the accessory and divided by the diameter of the front element of the accessory or by the diameter of the aperture in the lens's aperture disk. Aperture For example, when using a 50mm lens with a standard 10x70 accessory the equation becomes (10x50) + = about 4/7. And this . The effective to be used for all future exposure calculations for this mode is

What is better to use a group of elongation rings or bellows?

Extension tubes (or extension rings) and bellows have their own uses in close-up photography, and this really depends on the type of work you intend to do, how close you want to be to the subject and how small the object is (Fig. 28 elongation tubes enable the lens to focus more tightly than close-up lenses do and to produce an image of it the same size as the object photographed (i.e. the magnification ratio is 1:1 and this is sufficient for objects the size of a postage stamp or a colored glass slide for copying One of the disadvantages of elongation tubes is that they give only fixed distances from the lens to the object to be photographed, but they are considered relatively cheap with the possibility of carrying and moving with them.

As for the bellows devices, on the other hand, they are relatively expensive, but they provide an unlimited variable range of distances through which the lens can focus its focus. There are many of these devices with which independent upward and transverse movements and tilting movements of the camera or the lens support platform are made. Which enables a certain degree of correction of perspective distortion and vertical lines grouped and controlled
depth of field. One of the minor disadvantages of the blower is that. The minimum elongation is often greater than the smallest elongation tube, so there may be a small area that cannot be covered between the area of ​​the unassisted lens and the lens attached when the bellows assembly is fully compressed