Application of viewfinder
The optical viewfinder is a tool to composition and review images before shooting. It also helps the photographer to choose the focal length of the lens. Also, when the light is low, it is a great help to image composition.
An important part of this device is the optical system. This tool should be able to create an image of super wide-angle at least 140 degrees, directly (no reverse). For this purpose, I used WinLens 3D software for basic design. And according to the patents, and study them, I have created a sketch. This lens is comprised of three elements in the two groups. The front section containing two negative lens and a positive lens is included in the back section.
The next step was cutting and polishing glass lens according to the design. After a long time search, I found artisan it, I ordered for the production. Next step, collection lens is built based on the design, should be assembly inside a chamber. Thus, external body of viewfinder, also designed and were made.
The composition system
But, for composition in landscape,with a variety of formats and lenses, I made special frames (mask) for it, which will be installed in front in viewfinder. To make this part, I used from a glass transparent plastic (Plexiglas). By using machines, according to lenses angle of view, I've carved frame with very thin lines. In this regard, I have tried as far as possible do remove error parallex. Table below shows selected format, compared to the focal lens in optical viewfinder.
|focal lenght of large format lens|
Optical viewfinder by using standard flash mount, can be installed on a variety of cameras.
Viewing Angle: 140°
Masks: 5 Piece, 6X6cm – 6X9cm – 6X12cm – 6X17cm – 4X5in
Material: Aluminum Alloy 7075
Internal Paint: Anti-reflective black
External color: Semi-gloss black coating
External dimensions: W:77, H:87, D:80 mm