What causes shorter Depth of field with larger aperture ?

BADGER.BRAD

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I have just finished my first Pinhole Camera (35mm) but after reading about them having a very large depth of field I wondered what actually causes depth of filed to become shorter with wider aperture ?
 

RalphLambrecht

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BADGER.BRAD said:
I have just finished my first Pinhole Camera (35mm) but after reading about them having a very large depth of field I wondered what actually causes depth of filed to become shorter with wider aperture ?
Click to expand...
the geometry of image creation.
 

removed account4

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hi brad

have you seen fellow appugger kier's pinhole website ?
http://fslashd.com
there are articles + other information there ...
also eric renner's website
https://www.pinholeresource.com
also william christiansen's pinhole edun
http://www.pinholeedun.com/

these places might answer questions about the nuts and bolts of
pinhole and lensless-apertures ...
they sell laser made pinholes cut on a metal shim and zone plates ( concentric circle pinholes )

good luck !
 

Jim Jones

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cowanw said:
Although, as pin holes do not have a plane of focus, neither do they have depth of field; every distance is the same sharpness (with a weeny quibble of closeup work).
Click to expand...
There is an optimum size pinhole for every combination of focal length, subject distance, and film color response. At this optimum size, a pinhole can resolve line pairs of a resolution test chart that have a spacing noticeably smaller than the pinhole diameter. This is because at that critical size, diffraction actually improves instead of degrading resolution. This improvement is noticeable in critical pinhole photography. However, we may chose to deviate from this ideal to improve off-axis sharpness or to alter the appearance of the image in other ways.
 
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