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| ＜Example＞ Sony DSC-W1 5.3
Megapixe Camera |
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Focal length of lens |
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f＝7.9〜23.7mm
f = 38~114mm (35mm film equivalent) |
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FStop |
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| The focal length is 38-114mm when converted into 35mm
film format. The actual focal length is 7.9-23.7mm. At the wide
angle the camera is F2.8 and at the tele angle F5.2. |
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| ＜Example＞ TSN-824M with
the TSE-14WE (32×W) eyepiece |
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32×W：Effective focal length = 252.8〜758.4mm |
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| 32×7.9=252.8 / 32×23.7=758.4 |
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F Stop Calculation
F= Effective focal length ÷ Objective lens size |
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252.8 ÷ 82 =
3.1 (Wide Angle)
758.4 ÷ 82 = 9.3 (Tele Angle) |
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FStop |
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| ＜Example＞ TSN-824M with TSE-21WE
(21×W) eyepiece |
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21×W：Effective focal length = 165.9〜497.7mm |
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21×7.9=165.9 / 21×23.7=497.7 |
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F Stop Calculation
F= Effective focal length ÷ Objective lens size |
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165.9 ÷ 82 =
2.0 (Wide Angle)
497.7 ÷ 82 = 6.1 (Tele Angle) |
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When as above, the calculated F
Stop of the system is smaller (brighter) than the F stop of the camera, the F
Stop of the camera will be the F Stop of the system. |
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