Canon 40D - EOS 40D DSLR, Руководство по обслуживанию

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Technical Information
8
1.5 Viewfinder
１）Viewfinder optics for easy viewing
With an optimized pentaprism and larger
diameter eyepiece lens, the viewfinder
looks bigger with less vignetting. Fig. 013
compares the viewfinder coverage with the
EOS 30D's viewfinder. Table 006 compares
the specifications.
Table 006 Major Viewfinder Specifications
Item EOS 40D EOS 30D
Coverage [Approx. %] 95
Magnification [Approx.] 0.95 0.9
Viewing angle [ ] 26.4 25.1
Eye point [Approx. mm] 22
＊
20
Dioptric adjustment [dpt] -3 - +1
＊ The EOS 40D's 22mm eyepoint is the distance at which the viewfinder image area can be viewed without any
vignetting of the viewfinder (on all four edges). Normally, most manufacturers define the eyepoint as the distance
where both the viewfinder image area and information display are visible. Therefore, when stating the eyepoint, also
add a note indicating that it is the distance where the viewfinder image area can be viewed without any vignetting on
all four edges.
２）Superimposed display
The basic configuration of the superimposed display optics is the same as the EOS 30D's.
３）Ef-series focusing screens
The Ef-series focusing screens have been newly developed. Ef-A Standard Precision
Matte, Ef-D Precision Matte with Grid, and Ef-S Super Precision Matte are available.
All three focusing screens have a fresnel lens area produced by a technique attaining
excellent transfer characteristics. This results in a bright focusing screen. (Same production
technique used for EOS-1D Mark III's Ec-C IV focusing screen.)
Eyepiece lens 1
Eyepiece lens 2
Eyepiece lens 3
LCD in the viewfinder
Main mirror
Focusing
screen
Pentaprism
SI lens
SI reflective plate
Fig. 014 Viewfinder Optics
: EOS 30D viewfinder coverage
Fig. 013 Viewfinder coverage comparison