Modern digital mirror cameras are most often used for focusing the optical viewfinder. Amateur photographers call it simply ‘peephole‘. Abbreviated Optical Detector called OVI. OVI differ from each other in optical crystal, coating and zooming in, focusing displays, lightening and used LCD, LED displays. In this article I want to describe exactly the size of the HVI.You can look here about how the work of the HUR on a modern SLR camera is arranged. When shooting on different cameras, I very often encounter the fact that different cameras have different OVIs, it is pleasant to work with some cameras because of a good OVI, and others have a small and ‘dark’ one. Usually in the characteristics of the cameras for the description of the HUR, there are two parameters:
Frame coverage – frame coverage (viewfinder coverage). For example, for a Nikon D5200 camera, it is indicated that Frame coverage = Approx. 95% horizontal and 95% vertical
Frame Magnification – frame magnification (viewfinder magnification). For example, for a Nikon D600 camera, it is indicated that Viewfinder Magnification = Approx. 0.7x (50 mm f / 1.4 lens at infinity, -1.0 m-1)
Both of these parameters are very important. Frame coverage is set in percent, and shows how much space vertically and horizontally from the actual image can be seen through such a HUR. For example, if it is indicated that the HUR has 95% vertically horizontally, this means that only 95% of the central image of what is in the image can be seen in the HUR. After the picture is taken, an extra image will be added to the edges, which was not visible in such a JVI. It sometimes annoys me that on some cameras there are parts of what I did not plan to include. Most often this is the front lens of the lens of my videographer, part of the person in the frame, any other extraneous details. This picture then have to crop.
In fact, if the HUR displays only 95% of the image vertically and only 95% horizontally, then by the area itself the HUR displays only 90% of what is in the picture. It turns out with such an HVI 10% of the image is simply not visible. Manufacturers specifically indicate the percentage of the width and height of the frame, as a figure of 90% in area could have alerted many when buying such a camera. Few people pay attention to the frame coverage. Good cameras should have a 100% coverage of the field of the frame, in such cameras everything that you see in the JVI will be on the image and there will definitely not get anything extra.
If your camera doesn’t have 100% frame coverage, then Live View can always come to the rescue, which gives you 100% coverage of the field of view. Also, modern cameras with an electronic viewfinder almost always provide 100% coverage. You can also simply get used to and anticipate the possibility that something extra can climb into the frame.
Another important indicator of JVI is its immediate value.
The Frame Magnification parameter is usually responsible for the value. The more HVI, the more convenient to work with him. The real difference in the magnification of different OVI can be felt when comparing full-frame cameras and full-frame cameras. Full-frame cameras usually have a much larger viewfinder with an increase of 0.7-0.8x, but the cameras that go with increase with 0.8-0.95X. The picture above shows how much the viewfinder is different for different cameras.
Usually the ‘bad’ jies have old crooked SLR cameras. In such cameras, for example, in the Canon 350D, Nikon D40, the OVI is very small, through it it is not always so easy to disassemble what is in the frame. Especially important is a good JVI when working with ‘dark lenses’ and with the manual focus method. By 95% over time you just get used to it.
Usually photographers work with a reflex camera looking at space with one eye through the HUR, this is a good, time-tested method of sight. Choosing a camera for yourself is very important to have a good HUR that will help in the work and will not force the photographer to squint with all his strength to see the details of the picture.