Aperture and Dust
Apr 2, 2020 07:49:03 #
johnec
Loc: Lancaster county, PA
On a different forum I read where a Nikon D850 user sent his camera to Nikon for sensor cleaning because dust was showing up in images. According to him, Nikon cleaned sensor but told him that shooting at high f-stop, because of high resolution in D850, would show dust that couldn’t be removed. He was advised to shoot at lower f-stop. Could someone please explain to me why, when shooting at any given ISO and shutter speed, reducing the amount of light getting to the sensor (f22 versus f12) would more easily reveal sensor dust?
Apr 2, 2020 08:02:24 #
Not sure. A high f number would be the smallest opening and use only the central part of the glass, so doesn't make sense. Dust on the lens doesn't show much because the same point in the world strikes the lens everywhere. It's the same exposure value no matter what combination of aperture and shutter. Perhaps you misunderstood? Lens aberrations are more evident at the lowest f numbers, diffraction is more evident at the higher f numbers, Maybe that is what they are referring to.
Do you know it is April 2nd?
Do you know it is April 2nd?
Apr 2, 2020 08:08:21 #
Apr 2, 2020 08:11:01 #
LWW
Loc: Banana Republic of America
johnec wrote:
On a different forum I read where a Nikon D850 use... (show quote)
Depth of field.
Apr 2, 2020 08:17:03 #
Linda From Maine wrote:
https://photographylife.com/why-sensor-dust-is-more-visible-at-small-apertures
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I wouldn't have thought of that in a million years.
Apr 2, 2020 08:19:38 #
bleirer wrote:
I'm looking forward to the UHH techies expanding our knowledge further (maybe with more detailed charts and graphs?) I wouldn't have thought of that in a million years.
Apr 2, 2020 08:25:56 #
johnec wrote:
On a different forum I read where a Nikon D850 use... (show quote)
I don't know why either but it does. It has nothing to do with the amount of light striking the sensor because using a smaller aperture and increase the light on the subject still reveal the dust more. However, doing test I can't see dust at f/5.6 or f/8.0 but certainly I can see them at f/22.
Apr 2, 2020 08:28:14 #
Linda From Maine wrote:
I'm looking forward to the UHH techies expanding our knowledge further (maybe more detailed charts and graphs?)
Don't encourage them Linda😆
Apr 2, 2020 08:30:30 #
A lot of cameras have dust delete data as an option, but I think it only works if you use the software that comes with the camera.
Apr 2, 2020 09:54:48 #
BebuLamar wrote:
I don't know why either but it does. It has nothing to do with the amount of light striking the sensor because using a smaller aperture and increase the light on the subject still reveal the dust more. However, doing test I can't see dust at f/5.6 or f/8.0 but certainly I can see them at f/22.
It’s similar to the difference between sharp shadows your get from a small hard light source vs softer shadows from a larger one.
Linda’s link above explains it well:
https://www.uglyhedgehog.com/t-639275-1.html#11082792
Here’s an illustration from it:
Apr 2, 2020 10:00:04 #
johnec wrote:
On a different forum I read where a Nikon D850 use... (show quote)
Below are two of the three links you might consider for why you don't need to get smaller than f/11 on modern digital cameras. Since there was a request for charts, graphs and equations, that link is responds to Linda's comment. So beyond revealing dust, the photographer at small apertures is creating softer images, not sharper.
https://www.cambridgeincolour.com/tutorials/diffraction-photography.htm
https://luminous-landscape.com/understanding-lens-diffraction/
Apr 2, 2020 10:00:54 #
Linda From Maine wrote:
I'm looking forward to the UHH techies expanding our knowledge further (maybe with more detailed charts and graphs?)
This post should have enough equations to make one's head hurt and why you don't need to be smaller than f/8 to f/13 with your modern digital cameras.
https://expertphotography.com/lens-diffraction/
Apr 2, 2020 11:08:45 #
GoofyNewfie wrote:
It’s similar to the difference between sharp shadows your get from a small hard light source vs softer shadows from a larger one.
Linda’s link above explains it well:
https://www.uglyhedgehog.com/t-639275-1.html#11082792
Here’s an illustration from it:
Linda’s link above explains it well:
https://www.uglyhedgehog.com/t-639275-1.html#11082792
Here’s an illustration from it:
Thanks goofie!
Apr 2, 2020 11:10:18 #
BebuLamar wrote:
Thanks goofie!
Thank Linda.
I just copied and pasted.
She’s awesome!
Stay well everyone.
Apr 2, 2020 12:35:12 #
johnec wrote:
On a different forum I read where a Nikon D850 use... (show quote)
[Captain Obvious here removing his post that would have not been posted had he read the other responses]
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