Camera Encyclopedia

Paraxial camera theme * * * is divided into three parts:

What is paraxial camera and its early development (I)

(2) The development of modern paraxial camera and its comparison with SLR camera (to be continued)

Introduction of Classic Paraxial Camera (Ⅱ) (to be continued)

Further reading: Camera Encyclopedia | What is a SLR camera?

Paraxial camera, also known as paraxial camera, is named "paraxial camera" because its viewing optical axis is located next to the optical axis of the photographic lens and parallel to each other.

In the whole process of camera technology development, paraxial camera is the most diverse category, and its structure is also very different, so it has the most cultural characteristics. From the outstanding Leica products, to the famous Lulai double reflex, and then to the world's first paraxial digital camera Epson R-D 1, they are all members of paraxial cameras, so paraxial cameras are undoubtedly an important part of camera development.

The paraxial camera we usually call now basically refers to the range finder camera (RF). But it's just a paraxial viewing system. RF is paraxial, but paraxial is not just RF.

Before the design of the single-lens reflective viewfinder system, the paraxial viewfinder system was the most widely used viewfinder system, and its viewfinder was also improved from the early head-up viewfinder (or optical viewfinder, that is, the viewfinder used on a fool's machine).

Because the paraxial camera uses an independent viewfinder, there will be some parallax at close range, but some advanced paraxial cameras will design parallax compensation mechanism.

Due to the limitation of the paraxial camera's own structure, it is impossible to install a super telephoto lens, so it was later replaced by a SLR camera.

Paraxial camera is widely used in documentary photography, humanistic photography and landscape photography because of its compact body design, and the reflector of SLR camera has no noise and vibration when working, and the wide-angle lens and ultra-wide-angle lens are far stronger than SLR camera.

In the early days of the camera industry, hand-made camera products were mainly influenced by painted black boxes, and products with wool screen coaxial viewing mode occupied an important position.

However, the use of rough screen framing is greatly limited.

On the one hand, restricted by the development of early photosensitive materials, enough ambient light is needed to take pictures; On the other hand, rough screen images are easily disturbed by external stray light when taking pictures, which leads to contradictions.

We know that contradiction will definitely lead to change, so this contradiction finally stimulates the change of framing method, and paraxial framing is the most thorough product of this change.

There were several types of early paraxial cameras. From the structure of paraxial viewfinder, the simplest one is called frame viewfinder, which can be installed on any coaxial viewfinder as an additional viewfinder.

Because the principle of frame viewfinder is simple and easy to make, its framing accuracy is basically acceptable when shooting scenes at a certain distance, so the products equipped with frame viewfinder in early cameras are more common, such as Chambre Automation1860 produced in France and Eka 1924 produced in France.

Look at the picture below. Is the frame viewfinder on the camera simple, like a sight?

Another viewfinder device with lens on the basis of frame viewfinder is called Newton viewfinder, which consists of negative lens (also called concave lens) and frame. The characteristic of this viewfinder is that it can be made much smaller under the condition of obtaining the same field of view, and it is possible to get a brighter viewfinder with good lens material.

Le Pascal 1898 produced in France, Ernemann j tropical 1904 produced in Germany and Ensign Cupid 1922 produced in Britain are all cameras with Newton viewfinder.

As another kind of paraxial camera, dual-lens reflex camera appeared in the late19th century. Its principle is to image the scene whose optical axis is at a 90-degree angle with the reflector on the wool screen through one or a group of positive lenses (also called convex lenses), and the viewing optical path is vertical. Because the framing lens and the photographic lens are axially parallel and adjacent, the framing error is greatly improved, and this advantage is very prominent, so it is rapidly popularized.

For example, 1887 French-made Kinegraphe and 1889 German-made Krugener Simplex belong to the early products of dual-lens varieties;

At the same time, reflective viewfinder with the same principle as dual-lens reflective camera is also widely used, such as Le Royal Detectif o Ultime Special produced in Belgium in 1893 and folding mahogany Rodolphe produced in 1903.

Bright viewfinder is actually a variant of reflective viewfinder, which was popular at the end of 19 and the first half of the 20th century.

The main difference between it and the reflective viewfinder is that it uses a positive lens instead of a wool screen, so that the spatial image of the scene can be obtained and the viewfinder becomes very bright. However, the change of eye position often affects the viewing range and often causes the feeling of eye discomfort. So later, the bright viewfinder was mainly used as an additional viewfinder. 1905 Kodak's 1 folding pocket camera is one of many products that use bright viewfinder.

This bright viewfinder, in turn, paves the way for the promotion of simple dual-lens reflex cameras.

Compound viewfinder is another milestone in the development of early paraxial viewfinder. It installs two or more paraxial viewfinders on a camera, providing a variety of viewfinder modes. The biggest feature of compound viewfinder is that it gives users more choices. For example, Newton viewfinder and bright viewfinder are combined on the camera to provide two framing methods: head-up framing and waist-down framing;

Or combine the frame viewfinder and bright viewfinder on the camera to provide the same framing requirements.

The appearance of composite framing device has certain influence on the design of advanced products in the future. For example, in 1949, the German-made Pu Lauber Makina III D evolved this classic composite framing device, although the framing technology was greatly improved during this period.

In fact, the early paraxial cameras provided some necessary framing methods, and the beauty, convenience and miniaturization of the cameras were later (talk about it in the next issue, don't worry).

Next notice

Speaking of paraxial cameras, we have to talk about Leica. As the most classic representative of RF cameras, what kind of history has Leica M series gone through?

After World War II, Japan's camera industry developed rapidly. What are the characteristics and advantages of Japanese paraxial camera? (Not only cheaper than German cameras, right? )

Since it comes to paraxial, it is inevitable to compare it with SLR system. What are their advantages and disadvantages?

Don't worry, I'll tell you everything next time.