Depth of field question: Maybe I'm overlooking something obvious, but I wonder if someone could explain in somewhat simple terms why it is that a smaller aperture creates greater depth...

Inthewoods

Maybe I'm overlooking something obvious, but I wonder if someone could explain in somewhat simple terms why it is that a smaller aperture creates greater depth of field.

rwilson1942 Loc: Houston, TX

Google is your friend.
https://physics.stackexchange.com/questions/83303/why-does-aperture-size-affect-depth-of-field-in-photography

orrie smith Loc: Kansas

Inthewoods wrote:

Maybe I'm overlooking something obvious, but I wonder if someone could explain in somewhat simple terms why it is that a smaller aperture creates greater depth of field.

You are possibly misunderstanding aperture. A smaller number aperture is actually a larger aperture, or more open if you will. 1.4 aperture would relate to a larger opening and would bring less into focus than an 8.0 aperture, resulting in more depth of field. Hopefully that helps.

Linda From Maine Loc: Yakima, Washington

Another article for the OP about the physics: https://photographycourse.net/physics-of-depth-of-field/

orrie smith wrote:

You are possibly misunderstanding aperture. A smaller number aperture is actually a larger aperture, or more open if you will. 1.4 aperture would relate to a larger opening and would bring less into focus than an 8.0 aperture, resulting in more depth of field. Hopefully that helps.

The OP's question seems straight forward - wanting to know the "why."

But you bring up an interesting discussion about whether it's common or correct to refer to a "smaller-number" aperture. I have always used the term relating most closely to the physical reality (smaller aperture), not the number.

jaymatt Loc: Alexandria, Indiana

Smaller number = bigger opening = more lens curvature = less depth of field because of rounder lens area.
Larger number = smaller opening = less lens curvature = more depth of field because of flatter lens area.

Inthewoods

rwilson1942 wrote:

Google is your friend.
https://physics.stackexchange.com/questions/83303/why-does-aperture-size-affect-depth-of-field-in-photography

I guess I WAS overlooking something obvious.

dyximan

jaymatt wrote:

Smaller number = bigger opening = more lens curvature = less depth of field because of rounder lens area.
Larger number = smaller opening = less lens curvature = more depth of field because of flatter lens area.

I like your answers and style, to the point, and actually answered the question as asked. thank you.

Inthewoods

dyximan wrote:

I like your answers and style, to the point, and actually answered the question as asked. thank you.

Yes.

jaymatt Loc: Alexandria, Indiana

dyximan wrote:

I like your answers and style, to the point, and actually answered the question as asked. thank you.

You’re welcome. I was a writing teacher, so . . . .

alby Loc: very eastern pa.

jaymatt wrote:

Smaller number = bigger opening = more lens curvature = less depth of field because of rounder lens area.
Larger number = smaller opening = less lens curvature = more depth of field because of flatter lens area.

good explanation.... always wondered myself.... lens curvature.... thanks

CHG_CANON Loc: the Windy City

It's science. There are not easy terms.

Chaostrain Loc: Hillsboro, Oregon

I've narrowed it down to the smaller the F-stop number the smaller amount of focus area in the photo. I'm good with that. Any more explanation would just be confusing.

jaymatt Loc: Alexandria, Indiana

Chaostrain wrote:

I've narrowed it down to the smaller the F-stop number the smaller amount of focus area in the photo. I'm good with that. Any more explanation would just be confusing.

pbradin Loc: Florida

the simple explanation is that the smaller aperture only allows the light coming through center of the lens to be used to make the image, and that light is not being bent as much as light coming from the outer edges of lens, where that light from those outer edges is being bent a lot more and traveling a longer distance.

jerryc41 Loc: Catskill Mts of NY

Inthewoods wrote:

Maybe I'm overlooking something obvious, but I wonder if someone could explain in somewhat simple terms why it is that a smaller aperture creates greater depth of field.

It's for the same reason that squinting makes things look sharper. You can get the same effect by making a pair of binoculars out of your hands and looking through them. You will see more clearly because you are blocking extraneous light.