Автор: Nedelcho1
Дата: 23-04-14 10:02
Колко много писаници и спорове, без нито едно приведено доказателство .
Хайде един линк, да видим какво са изчислили учените .
http://www.clarkvision.com/articles/human-eye/index.html
The Focal Length of the Eye.
What is the focal length of the eye? I did a google search and found many "answers" ranging from 17mm to 50mm (50 is totally absurd). For the correct answer, is Reference: Light, Color and Vision, Hunt et al., Chapman and Hall, Ltd, London, 1968, page 49 for "standard European adult":
Object focal length of the eye = 16.7 mm
Image focal length of the eye = 22.3 mm
The object focal length is for rays coming OUT OF THE EYE. But for an image on the retina, the image focal length is what one wants. E.g. see: http://galileo.phys.virginia.edu/classes/531.cas8m.fall04/l11.pdf.
So this explains the commonly cited ~17mm focal length, but the correct value is ~22 mm focal length
This then makes more sense for the f/ratio: with an aperture of 7 mm, the f/ratio = 22.3/7 = 3.2.
Of course these values vary, with cited values from 22 to 24 mm, same with the aperture. The maximum aperture also decreases with age.
T.e. 22.3 mm f/3.2
Публикацията е редактирана (23-04-14 10:02)
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