Figure 2-91 Vertical plate camera
1 – prism and lens 2 – Lighting 3 – original frame Yard Flags And Banners
Vertical process camera sensitive film frame and the original frame is perpendicular to each other, plus in front of the camera's prism, 45 ° bevel the original image reflection, image reversal, and then through the lens reversed, so that the sensitive film on the original image Yam in the same direction like. Cheap Flags For Sale
The composition of (4) plate camera. Plate camera is the main tool for photoengraving, which consists of a rack, the original frame, the camera obscura, lenses and photographic equipment. Yard Flags And Banners
issued on frame: to fix original, you can move back and forth to adjust things distance.
(b) Lens: the lens is the lens group barrel and aperture lens group is the most important part.
The main parameters of the lens as follows: Customized Flags Order
Focal length: a bunch of parallel light through the lens converging point, the point called the focus, the focus distance to the center of the lens is called the focal length.
Field, like a field, refers to the lens like angle: the so-called lens photographic ability, in the sensitive film on the scope of the image clear. Called as nodes in the field external to the lens open angle like the angle.
The aperture of the lens aperture factor: Yard Flags And Banners
a) the effective aperture: the maximum diameter of the lens and the focal length ratio.
b) The relative aperture: all levels of the light-hole diameter and focal length ratio.
c) the scale of the aperture factor: Aperture factor at all levels, namely the relative aperture, the scale of the common at all levels of relative aperture: F5.6, 8,11,16,22,32,45,64,90. The scale of the aperture coefficient based on every change a light hole, and then doubled to reduce or increase the luminous flux through the lens scale. : Aperture from F8 to 11, reduced by the luminous flux of the lens to double the contrary, the luminous flux of the lens is doubled. Best Flag Quotes
Resolution: The resolution of the lens of the lens is clearly the ability to reproduce the objects most small parts. Usually sand in the aperture (F11-22), the resolution capability of the width and equally spaced lines to measure, namely the number of lines per mm can be recorded.