1
$\begingroup$

When reading about the basics of photography and the physics involved, I learned about  depth of field. Long story short, the message is that with a smaller aperture, the length of the depth of field increases. For a wide-open aperture one gets a smooth bokeh for example.

The human eye does have an aperture as well (the iris). But I never noticed seeing any different with respect to depth of field no matter if it was a darker (wider iris) or brighter (narrow iris) environment.

Why is this difference presumably not as pronounced as it is for photography? Or am I mistaken?

Improve this question
$\endgroup$
1
  • $\begingroup$ The same principle applies to eyes. That's a major reason why squinting can help you see more clearly. See invision2020.com/see-better-squint $\endgroup$
    – D. Halsey
    Commented Jun 12, 2018 at 21:09

2 Answers 2

Reset to default
3
$\begingroup$

Because your eyes are young, you will not experience a difference.

However, once you age, depth of field makes a BIG difference, because your eye gradually loses the ability to shift the focus of the lens. To see close objects sharply then requires bright illumination so your iris contracts to a small opening and your depth of focus goes up; this compensates for the loss of ability to focus on close objects.

Improve this answer
$\endgroup$
1
$\begingroup$

With increasing age power of accomodation to vary iris diameter diminishes. So to compensate for focussing inability (contraction of tiny sphincter like muscles in the iris that work like the diaphragm in a camera) brighter objects are used/needed by the old. You seem to be young with no such problem.

Improve this answer
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.