P8
Film and Digital -- Angle of View and Focal Length
Film :
300mm
Digital :
200mm
Digital :
50mm
Film :
78mm
Digital :
18mm
Film :
28mm
*Film = 35mm format.
Telephoto 7˚59'
Standard 31˚11'
Wide 75˚33'
*Digital = Digital cameras with smaller-size imagers.
P7
Designed to fit smaller-size image sensors
in order to reduce its diameter
General
Image sensor
*When pictures taken with a
Di-II lens mounted on a 35mm
film camera or digital SLRs
with image sensor larger than
24mm x 16mm, image corners
become dark ( ie., vignetting
becomes noticeable).
Image circle
for Di II lenses
Vignetting
when used
with a 35mm format camera
35mm Film
When designing a lens having a short focal length range (when designing a
wideangle lens), the diameter of the lens inevitably becomes large. However, in
designing the 18-200mm Di II lens, Tamron has successfully solved this problem
by using an image circle designed to match that of general image sensor (smaller-
size image sensor), achieving almost the same compactness as the 28-300mm
lens (A061), which offers the same angles of view produced in 35mm film format.
36mm
24mm
about
23.2mm
about
15.5mm
