If you like photography, keep in mind that the viewfinder is an essential part of a camera.
The camera system in the viewfinder may vary depending on the type of camera.
And what is the visitor for? What’s your goal?
The viewfinder is used to process images captured by the lens, it also works by setting the composition, before the camera records the image.
Many cameras use the sensor to allow a preview on the LCD screen, so the most used system was the SLR or Single Lens Reflex, so that the photographer can see the optical projection through the lens.
Display structure
The main viewing sessions are:
We’ll talk about each of these elements soon.
Focus screen
The light passes over the mirror, which forms an image through the viewfinder, supported by the same light that is projected onto the surface.
Condensation lens
This lens, called convex, has a mission to focus the image, act on light capture and make the photo brighter.
Single digital lens
This type of lens combines optics and mechanisms with a digital image sensor, unlike the photographic film, in this lens, the light passes through the lens and then goes to a mirror that alternates to send the image. When using a single lens, a DSLR viewfinder displays an image captured by the camera sensor.
The mirror of this camera allows the lens light to create exposure.
Pentaprisma
This lens allows light to appear in several directions, so its polyedral prism changes the direction of light. The shape of this lens allows the camera to capture an image in the viewfinder, very similar to what the human eye is able to see, thus giving more clarity and naturalness to the images.
The base of this lens receives the image that is inverted in the condenser lens and jumps to the image 3 times, before you can project the image into the camera viewfinder.
Contact lens
This type of lens can change the size of the image and can be composed of several lenses. And thanks to it, you can take very nice photos, adjusting the distance of the eye lens from the camera.
Principles for displaying information on the screen
Different types of data are displayed in the viewfinder, such as: camera status, exposure settings, and AF collimator position.
Information presented outside the field of view is sent to the pentaprism, through prisms and display units, immediately reflecting inside the pentaprism to reach the eyepiece in the same way that images are captured.
The information presented in the field of view is overlapped or displayed by a communicative liquid crystal.
The overlay method is to overlay the red light indicating AF collimators, which are selected for the image in the viewfinder.
There are two ways to overlay the cameras; the first can be mentioned with an overlay made directly on the viewfinder, and the other with a dichroic mirror to reflect the information in the eyepiece. The dichroic mirror is an optical filter and has the characteristic of reflecting light with the length of a given wave, allowing light to pass through it.
Method of transmitted liquid crystals
This method involves placing the liquid crystal between the focus screen and the prism prism so that the LCD information is placed in the photographed image, to show af collimators.
Using liquid crystal, it is possible to display different types of information in the field of view, including the level of the electronic viewfinder and grids.
Viewer performance
The display performance is developed using 3 indexes, these are:
Roof
Coverage shows the percentage of the area covering the screen as part of the image, and even when the lens is changed, it remains unchanged.
If the coverage is less than 100%, parts of the shooting results cannot be viewed through the viewer.
The maximum coverage is 100%, so if there is more, it will mean that some parts will be visible in the photographed images.
augmentation
The playback rate is part of a technical term for photography and defines the size of an object’s image.
Enlargement has a similar meaning. In other words, the image magnification is displayed through the viewer. This image index is seen by the human eye as a number 1 of height/width ratio, i. e. the lower the height/width ratio, the smaller the image on the screen.
The size of actual images will change depending on the focal length of the camera lens. This means that magnification and magnification will be defined according to the specific measurement condition.
Here are some examples
If you have a 50 mm lens, it means you will have a focal length of 50 mm, adjusting the focus to infinity, without having diopters in the viewfinder (focus).
The m?1 unit is used for diopters and indicates a refractive index that is mainly used for DSRL glasses and cameras, which are usually 1 m?1.
This value indicates that you can clearly see 1 m in front. By adjusting the diopter to negative values, the myopia can be corrected. Hyperopia requires adaptation to positive values.
Viewing angle
This angle indicates the area where the eye can be separated from the viewfinder. The higher the angle, the greater the view of possible movement.
Point of view
Displays a tolerable area, where the eye can move slightly away from the eyepiece while you can see the image through the camera viewfinder.
After this course, discover the options of professional and semi-professional cameras!