Mikrotron eosens TS3, Руководство пользователя, Страница: 99 / 120

TS3 User Manual
page 90
Appendix J: Crop Factor
Crop Factor is a term used in digital photography that expresses the size of the sensor image
plane as compared to that of 35mm film. In Figure 9-9 through Figure 9-11, below, the Black
border represents the image on 35mm film, the R ed border represents the image on the sensor
using the same focal length lens.
Diagonal of 35mm film / Dia g onal of the Sensor area used = Crop Factor
The diagonal of 35mm film is 43.3, c ompared to the 22.95mm diagonal of the TS3, you get a
crop factor of 1.89:
43.3mm / 22.95mm = 1.89
The photographic advantage of knowing the crop factor is that if you know the lens you would use for
a given field of vi e w with a 35mm camera, you can divide the crop factor into that number to give you
the focal length of the lens with the same field of vi e w for your TS3. For example, if you are using a
125mm lens on your 35mm SLR, you will need about a 65mm lens on the TS3 at full resolution
(125mm / 1.89 = 66.14).
H-Res V-Res Diagonal Crop Factor
1280 1024 22.95 1.89
1280 720 20.56 2.11
1024 1024 20.27 2.14
1280 256 18.27 2.37
800 600 14.00 3.09
1024 600 16.62 2.61
640 480 11.20 3.87
800 480 13.06 3.32
512 512 10.14 4.27
320 240 5.60 7.73
320 200 5.28 8.20
256 256 5.07 8.54
Figure 9-9: Crop Factor 1280 x 1024
Figure 9-10: Crop Factor 1280 x 720 Figure 9-11: Crop Factor 800 x 600
Table 9-7: Crop Factor