صنع الطبعات الفوتوغرافية ٢-a .. كتاب طبع وتحميض الصور الفوتوغرافية

The aperture of the lens the smaller the depth of its field, and thus the objects behind and in front of the object focused on it will appear selectively sharper if the aperture of the lens used is at f 22 - i.e. the smallest possible aperture - unlike when the aperture of the lens is at f 2.8

For example - large aperture lens. Thus, you now know that the aperture controls the amount of light entering the camera and the depth of field as well.

Magnifier again:

The aim of the magnifier is simply to enlarge the negative that is backlit as explained above. Negative lighting must be equal to it in order to be effective and correct.

It is possible to place a piece of milky glass behind the negative with the brilliant light source between the lamp and the negative to disperse the light and distribute it evenly. However, this measure does not provide strong lighting for the negative and does not always distribute the light evenly over its entire surface. Therefore, a more effective method was devised to achieve this, which is to put two convex lenses between the lamp and the negative in a way that makes the light directed to the negative in the form of a flat and strong beam. These lenses are usually thick in the middle and have a short depth

44 - Schematic view of the amplifier elements.

- the Flashlight . Base plate.

B - capacitors

C - negative holder.

D-lens.

Condensers are very condensers, and sometimes the lenses themselves are called condensers for short. The condenser provides a reliable way to illuminate the entire negative surface
equally.

In addition to the condenser, a magnifying lens is placed, projecting the image of the negative onto a flat surface below it. It is worth noting that the double condenser and the zoom lens are used in the slide show.

There are several common features between a magnifier lens and a camera lens. There are also regular lenses for the magnifier, which is a 50 mm lens, which is considered a lens for 35 mm magnifiers and for 35 mm cameras as well, although the two devices use two different 50 mm lenses.

A 75mm 4 lens, if the size of the film you use in your camera is an inch or 80mm, is considered normal for both the camera and the magnifier. 2

The normal lens in the enlarger allows enlarging a print up to a size of 27.5 x 35 cm with the normal enlarger. Similar to a camera lens, a magnifier lens also has an aperture, but since the image it displays is of two dimensions only, the depth of field is not given much importance in comparison to the importance of distributing the light evenly over the entire surface of the negative.

As in the camera, the focus must be adjusted in the magnifier when the distance between the negative and the focused image changes. As for the magnifier, adjusting the distance between the focused image that it displays and the negative due to a difference in the size of the focused image - the farther the magnifier is from the focus surface, the larger the image size - and of course it requires the depth of field of the lens To adjust whenever it changes its position in relation to the image, and because the magnifier magnifies the illuminated negative according to demand, it is possible to maintain the size of the final print even when we use only a part of the negative. In clearer terms, when you want to print only part of the negative and delete the rest of it, you have to enlarge the image more than if you were to print it without deleting it. The process of removing a section of a negative is called cropping

Remember that the scene must be composed before pressing the shutter release button on the camera and not during printing, as the cropping process is not without disadvantages. Deleting part of the negative and enlarging the remaining part to obtain the normal size of the negative leads to a deterioration in the quality of the final print due to the increase in the clarity of the grains in it. The larger the size of the print, the greater the clarity of the grains in it.
buy magnifier:

Inexpensive amplifiers are not always bad, especially for an amateur in the beginning of the road like you. In general, there are basic things that must be available in the amplifier, whatever its price, and must be paid attention to when buying. The magnifier consists of a head containing the capacitors, the lens, the film holder, and a

A vertical column on which the head of the magnifier moves up and down, and from a base plate to display the image on it.

amplifier elements from the outside.

- Head . B - head height adjustment lever. D - the lens.

C - Focus adjustment lever.

l - vertical column. Base plate.

We recommend that you pay special attention to the lens and focus adjustment switches, to the negative mount, and to the mechanism for raising and lowering the head. It is better to try the magnifier at the seller in order to make sure the level of lighting it displays is equal. Ensure the quality of the lens with which the magnifier is fitted and the movement of the lens aperture by moving it from the smallest aperture to the largest aperture. Any error in the consistency of its work is evidence of a mechanical error in the aperture mechanism. After purchasing the amplifier, make some prints of good quality negatives and study the results. Details should be visible on all of the lens slots you used during the print, especially at the edges and corners of the print. Better zoom lenses are equipped with larger apertures (smaller f-stops) like better camera lenses, to make focusing easier, and cheap zoom lenses are equipped with cheap lenses with a maximum aperture of 4.5 f or less.

The job of the negative holder is to keep the negative inside it flat and at the correct angle of focus relative to the axis of the lens, so make sure the holder is perfectly seated in order to

focus quality. There are two types of holders: with a glass window, and without a window. The stand without a glass window in the middle consists of a removable metal frame on which the negative to be printed is placed completely. The negative is placed in the holder with a glass window between two thin strips

of glass. The better type between the two is the one without a glass window, because the glass causes dust to accumulate on it, and if it is not cleaned constantly, dust particles appear in the magnifications in huge sizes.

On the other hand, if the holder without a glass window is not well-made, it will bend the negative inside it, causing some parts of the slide that we are about to come out.

Reprinted from focus. If you are going to make prints from 35 mm films only, then your choice of the holder without a glass window is the best, and the enlargers intended for the use of 35 mm films only are the cheapest. 1 If you are going to make prints from large format films such as -2 x -2

inch, so your choice of the holder with the glass window is ideal because that size of the negatives is difficult to keep completely flat in the holder without a window. In general, the most important aspects of the magnifier are the lens and the stand, and then comes the mechanism for the head to work up and down. Is it easy to use or complicated and harsh?