ARRI ARRIFLEX 416
COMFORTABLE, ACCURATE & EFFICIENT
Advantages of Optical Viewfinders
Optical viewfinders, as used in all ARRI cameras, provide by far the most comfortable, accurate and efficient way to work when capturing images. Operators see a bright and sharp, full color image and are able to accurately judge focus. By their very nature, optical viewfinders have zero delay, showing exactly what is happening, right when it is happening.
Optical viewfinders show an area larger than the image recorded on film, ensuring that microphones, light stands and other debris do not make an ap- pearance in frame, thus minimizing the need for
In addition, optical viewfinders work without power, are less fatiguing to the eye than electronic viewfinders and can be equipped with a range of accessories such as medium and long eyepiece extensions, eyepiece levelers and heated eyecups. A large exit pupil ensures that the operator has more freedom to move without losing the image.
How Does an Optical Viewfinder Work?
An optical viewfinder is essentially a small rear projection screen and a mag- nifying glass. The taking lens projects light onto a screen; for 16 mm cameras this is usually a fiber optic screen, while for 35 mm cameras it is usually a ground glass. An image is formed on the screen. The screen has a specifically chosen granularity that allows the operator to precisely judge focus and depth of field.
The rest of the viewfinder is a very sophisticated magnification apparatus that allows the operator to view this image properly. Since the image on the screen will be magnified about 8 times by the viewing system before it reaches the human eye, high quality viewfinder optics and precision assembly are crucial. Through the use of mirrors and prisms the viewfinder can be
A small part of the light in the viewfinder is split off and directed to a CCD sensor, which creates a video image - the so called "video assist" - allowing others besides the operator to see the image.
The specific light path pictured here is from the ARRIFLEX 416 cameras, but it is similar in principle to that of all optical viewfinders.
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