(شرح جدول رقم ٤٤) مقدار الزيادة فى الوقفات Srors أو التعريض. 

(Explanation of Table No. 44)

The amount of increase in pauses, sorrows, or exposure.

In extreme close-up conditions

(Macrophotography) If we know the focal length of the lens, and the distance of each of the film and the body from the lens, then we will use a 35mm or 16mm camera.
(with lenses with focal lengths of 2, 3, 6,4 inches)

An introduction to extreme close up or macro photography

What is meant by this expression is the conditions in which the magnification ratio reaches 1:1 or more than that, i.e. the conditions in which the length of the image recorded on the film is equal to the length of the body in nature, or the conditions in which the length of the image is greater than the length of the body

Extremely close photography has another equivalent name, macrophotography, and it is well known that the conditions of extremely close photography in general are
You must use any of the following means:

(a) The use of additional positive supplementary lenses, sometimes known as Diopeter Lenses, to be placed in front of the original lens.
In camera .

(b) Use of extension tubes. extension tubes

(c) Use of an additional blower.
bellows extension


In cases B and C, both methods increase the distance between the photographic lens and the sensitive film in a way that suits the closeness of the distance between the lens and the object to be photographed. The closer the object is to the lens, the greater the distance between the sensitive film and the lens. and schedule
No. 44 p. 91 guides us in these two cases, on the following data.

1- The required increase in exposure or the increase in stops.

2- The magnification ratio, which is the scale of transmission (the ratio of image length to object length)?

3- The length of the extension pipes or the length of the bellows extension.

Example (1):

To know the amount of increase in stops when photographing close-up.

Assuming that I used a lens with a focal length of 4 inches (10) cm, and the distance between the diaphragm and the body = 4 inches, and the distance between the diaphragm and the film is 24 inches, in order to photograph a very small object. What is the amount of pauses to be increased?

Answer: From Table No. 44 91, we conclude that the number of stops to be increased is Y = E and Stops

Example (2):
To find out the amount of exposure factor nursing factor. That is, the increase in nursing.

Assuming that I used a lens with a focal length of 3 inches (7.5 cm), and the distance between the diaphragm and the body = 36 inches, and the distance between the diaphragm and the film = 18 inches, what is the exposure factor?

Answer: From Table No. 44 p. 91, we conclude that the exposure must be increased by 39 times.

Example (3) Knowledge of the Magnification Ratio

If the focal length of the original lens in the camera = 6 inches (15 cm) and the distance between the diaphragm and the body = 7 inches. The distance between the diaphragm and the film = 42 inches, so what is the scale of transmission or what is the percentage of magnification?

Answer: From Table No. 44 p. 91, we conclude that the magnification ratio = 6:1

Example (4):
​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​ ​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​ ​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​knowi ng the amount of bellows extension, or the length of extension tubes that should be used if we know each of the following: - (1) the focal length of the lens (b) the distance between the diaphragm and the body.

Assuming that you have a camera (whether 35mm or 16mm) with its original lens that has a focal length of 2 inches, and you want to photograph a postage stamp that is 24 inches away from the lens diaphragm, what is the length of the bellows extension or the length of the extension tubes that would allow photographing this The body is extremely close.

Answer: From Table No. 44 p. 91, we conclude that the length of the blower extension or the length of the extension tubes must allow that the distance of the film from the diaphragm be: 14 inches. It is noted that this dimension is the same as referred to in the table as (the dimension of knowledge about the diaphragm).