نظرية إستخدام آلات التصوير ذات الظهر المتأرجح للحصول على عمق میدان كبير .

The theory of using swing-back cameras to obtain a large depth of field:

(1) If we photograph an object with all its limbs located at a fixed distance from the imaging lens and the position of this object is perpendicular to the axis of the lens, then we adjust the distance according to its distance from the lens, we get an image of the object with sharp details: Sharp image even if the aperture of the lens used is large . This is a case in which there are no difficulties with regard to the depth of field, given that the edges of the body are at the same distance from the lens, as the body is round the lens, as the body is lifted on the axis of the lens, as shown in (Fig. His AB image is sharp in detail.

(2) The difficulty begins if the object being photographed is not perpendicular to the axis of the lens, as shown in Figure (44 “b”). If the distance is set on one end of the object as point B, an image of inflammation with sharp details will appear. As for the side A, its image will not be serious in detail if it is not adjusted. distance on this side.

(3) By using the camera with a swinging back, we find that it is possible to set the distance on each of the side closest to the object being photographed,

It also adjusts on the far side as well. (Fig. 44 (c), and it is noted that the side closest to A. The partition being photographed (side B) needs a different extension than that needed by the other side that is farthest (which is side A).

This process is done very simply by adjusting the distance on point A, then the extension of the blower is increased from the movable back on the other side until you see the closest point on the frosted glass, and the details have become sharp, then the movable back is fixed and imaging is done in the usual ways. The field, even if the aperture of the touch lens is, and thus we can combine the use of the large aperture needed to photograph fast movements. And between obtaining depth in the field .. and figures 45, 46 show us some of the results that can be obtained using this type of camera.