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Does the resolution effect depth of field

depth of field resolution sensor

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#1 davide sorasio

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Posted 27 April 2016 - 06:11 PM

Hi everybody, I apologize in adavence if the question is silly but: I know that the bigger the sensor the shallower the depth of field is, but does that translate in digital related to the resolution of the camera?

To be clearer, on the same camera, for example an alexa super 35mm cmos sensor, shooting 3.2k or 2k or standard HD is it gonna effect the depth of field?

Thanks for the help!

 


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#2 David Mullen ASC

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Posted 27 April 2016 - 06:40 PM

At best, all I can say is "sort of" -- a major component of the depth of field calculation is the Circle of Confusion, a rightly named concept, based loosely on the idea of how far can the focus be out before point become a noticeable circle instead, or in other words, what is the focus range around the correct focus distance where a point still looks like a point and not a fuzzy circle.  And that Circle of Confusion figure is based on the degree of image magnification, another fuzzy concept since we see images at all sorts of distances to the screen or monitor.  But we have to pick a figure in order to make the calculations.

 

So logically you figure that the more resolution that the image and display together have, the more clearly you'd see whether a point was in focus or not.

 

Another issue is edge contrast and how quickly or gradually detail falls out of focus, digital tends to have a more "abrupt" transition from sharp to soft which makes the image seem like it has less depth of field.

 

All this to say that traditional depth of field charts work on assumptions regarding the degree of enlargement and the Circle of Confusion figure chosen that may or may not be correct today.


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#3 Mark Dunn

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Posted 28 April 2016 - 03:56 AM

OP, the word you mean to use is 'affect'. 'Effect' as a verb means "to carry out", not "to have an influence on".


Edited by Mark Dunn, 28 April 2016 - 03:56 AM.

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