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Third: the types of lenses

The most important thing about a lens is its suitability for the subject to be photographed, not its brand, price, speed, or popularity. Based on this, we will briefly discuss the types of lenses and explain their use:

Standard or standard lenses: It features a speed of up to 1.8/F for the 35 camera or 5.6/F for the studio camera 4 x 5 inches. It is also characterized by a focal length close to the diameter of the film with which it is used. These lenses give a perspective close to what the human eye sees

Clearly. These are the most useful lenses and are often included with a camera

the purchase .

High-speed lenses: They are characterized by a lens speed (or a very wide pupil) that is wider than 1.8. These lenses are designed for speed, usually at the expense of some other properties. Therefore, we see that these lenses, compared to the standard lens, are larger in size, heavier in weight, more expensive, and usually less sharp and more vulnerable to the defect of unequal lighting.

These lenses are very necessary in the event that a very wide aperture is required, as in photographing subjects under inappropriate light conditions. Or to get a shallow depth of field for a subject or to stop a fast movement using the fastest shutter speed possible
It is not recommended to use these lenses in normal photography, although most companies now produce lenses with a speed of 1.4 / F, which correct most of the defects in an excellent way. As for the lenses 1,2, 1/F, these defects appear in a clear way.

Most of these lenses have a standard focal length, and some have a long focal length of up to 85 mm.

3- Wide-angle or obtuse lenses: These lenses are characterized by a shorter focal length than standard lenses, in addition to a greater coverage capacity - and while we find that the standard lens sees an angle of view of about 45, these lenses range from 60 to 180, and in these The condition is called fish-eye lens

These lenses are designed with one purpose, which is high coverage strength at the expense of other properties, which makes them more vulnerable to irregular light distribution defects and image distortion.

These lenses come in several types: (a) wide-angle lenses that give straight lines: these show straight lines as straight no matter how far they are from the center of the image, and their angle of view ranges between 60 and is used in architectural photography. And

(b) Wide-angle lenses distort straight lines: making the straight line more distant from the center of the image, the more curved it is to give barrel aberration. And we need these lenses in cases of shooting from a place very close to the subject and in other cases due to considerations
Artistic
(C) Fish eye lens: This has a viewing angle of about 180 degrees in all directions, and this type has a focal length of 8 mm to DM. These lenses are used for special technical purposes

It is not suitable for public photography at all

Wide angle lens uses:

(a) Let's get the whole view if that's not possible with a standard lens and we can't go back

(b) To exaggerate the spatial relations, we make the distance between the near and the far seem more than it really is.

(c) To get rid of things that blur the view, by approaching the subject to be photographed and leaving the distractions behind the camera.

(d) To obtain a large depth of field

.

(E) When we have to use a slow speed holding the camera by hand

(f) When using the camera from a vibrating surface, such as a train, for example.

(g) To photograph close objects.

Macro lenses: Close-up or macro lenses

The lenses are designed to give their best performance at short distances, which are measured in centimeters and millimeters, not meters. They are usually called macro lenses, although the company (Nikon) calls them lenses and micro

These lenses can usually be adjusted to give an image on the film of the size of the original object, and sometimes even a shade equal to the size of the original object.
We photograph the original body in a 1:1 ratio, and the focal length of these lenses for Camera (35) ranges between 100.50mm. These lenses are ultra-sharp and have no distortion or curvature in the field, so they can also have normal views. These lenses are slow, as their maximum pupil aperture ranges between F/2.8/F/4, F.

There is another type of these lenses that does not have a distance adjustment ring for use with the extension bellows to enlarge very small subjects up to 12 times the size of the original subject. These lenses are short focal length in the range of 18 mm to 35 mm.

Process lenses: These are relatively long focal length lenses. . It is characterized by sharpness, lack of arc in the field, and a small opening. It is used to transfer artwork or advertising photography for products. They are only available for large studio-type cameras of 4" x 5" and larger. pupil.

6- Soft-focus lenses: These lenses give images that are neither sharp nor blunt, but rather between. The boundaries of the subject consist of a sharp nucleus surrounded by a blunt halo. This lens is preferred by some photographers who specialize in photographing women and artists, as it hides wrinkles and gives softness to the skin. These are specialized lenses and they are not of much use except for the above.. These lenses are made by not completely eliminating the spherical aberration of the optical group. There are types that can control the degree of softness from completely sharp to very soft. This lens can be dispensed with by using a light-distributing filter in front of the lens
Telephoto lenses: These are long focal length lenses, but due to the development that occurred in the design of the lenses, they are no longer as large as they were previously. These lenses may tend to give aberration and sadism in some types.

A standard lens from the same place, and these lenses are given, compared to photography, a larger shadow on the film with the same ratio of the focal length. For example, a lens with a length of 100 mm gives an image that is twice as long as what is produced by a lens whose focal length is 50 mm, and so on.

These lenses are used for:

(a) To obtain a large image of a distant subject by bringing it closer to the camera optically.

(B) for portrait photography, where good proportions are given to the face

No distortion occurs.

(C) to compress the perspective and reduce the spatial relations, making the distance between objects appear closer than it is in nature) the perspective of the lens

telephoto??

. (D) To get rid of the noise in the image by photographing the required subject only and making the rest of the image that blurs the original subject not sharp, i.e. we get a shallow depth of field.

The disadvantage of these lenses is that just as they magnify the subject to be photographed, they also magnify any camera shake during photography. Hence it is necessary to be careful when photographing with such a lens that the camera is completely steady, or that it use the fastest shutter speed that can be used.