Home · Register · Join Upload & Sell

Moderated by: Fred Miranda

FM Forum Rules
Macro World Resource

FM Forums | Macro & Still Life | Join Upload & Sell

Archive 2018 · Some Thoughts On Diffraction Blur

e6filmuser
Offline
• • • • • •
Upload & Sell: Off

p.1 #1 · p.1 #1 · Some Thoughts On Diffraction Blur

The current wisdom seems to be that diffraction through small apertures is caused by collisions in crowded streams of photons.

That electrons are not in perfectly parallel paths must be due to imperfect alignment by an imperfect lens. However, there seems to be scope for reducing diffraction by using lenses of high quality and optimised for the application.

One way of reducing the crowding of electrons might be to use a longer exposure, at reduced levels of illumination, or lower ISO. This would require the subject to be static and the camera and lens setup free of vibration.

Has anyone tried anything like this?

Harold

Edited on Feb 20, 2018 at 04:52 AM · View previous versions

Feb 20, 2018 at 03:36 AM

charlyw
Offline
• • •
Upload & Sell: Off

p.1 #2 · p.1 #2 · Some Thoughts On Diffraction Blur

Sorry, what you write is absolute physical nonsense. Diffraction is an optical phenomenon - thus no electrons far and wide...

I'd suggest you first understand that Photons (the real fundamental particles behind light) do behave like waves in certain aspects (and particles in other) and that diffraction is linked with the wave side of their properties:

https://en.wikipedia.org/wiki/Diffraction

So it will not matter how uncrowded your light path is, it does not matter one iota - the same (in a statistical sense) amount of waves will be diffracted at the edges of the aperture, no matter how few pass through the lens in a given timeframe.

Feb 20, 2018 at 03:39 AM

e6filmuser
Offline
• • • • • •
Upload & Sell: Off

p.1 #3 · p.1 #3 · Some Thoughts On Diffraction Blur

charlyw wrote:
Sorry, what you write is absolute physical nonsense. Diffraction is an optical phenomenon - thus no electrons far and wide...

I'd suggest you first understand that Photons (the real fundamental particles behind light) do behave like waves in certain aspects (and particles in other) and that diffraction is linked with the wave side of their properties:

https://en.wikipedia.org/wiki/Diffraction

So it will not matter how uncrowded your light path is, it does not matter one iota - the same (in a statistical sense) amount of waves will be diffracted at the edges of the aperture, no matter how few pass through the lens in a...Show more →

The bending of light round corners theory is long dead.

This is from one of the leading specialists in the use of lenses in macro:

http://www.photomacrography.net/forum/viewtopic.php?t=6176&highlight=diffraction+theory

Harold

Feb 20, 2018 at 04:18 AM

charlyw
Offline
• • •
Upload & Sell: Off

p.1 #4 · p.1 #4 · Some Thoughts On Diffraction Blur

e6filmuser wrote:
The bending of light round corners theory is long dead.

Strangely it is healthy and highly vital in the link you posted. And still no electrons (which are charged particles no less and thus behave completely differently to photons which carry no charge) far and wide.

Feb 20, 2018 at 04:28 AM

alundeb
Offline
• • • • •
Upload & Sell: Off

p.1 #5 · p.1 #5 · Some Thoughts On Diffraction Blur

e6filmuser wrote:
Has anyone tried anything like this?

Harold

Yes, it does not affect diffraction.

Feb 20, 2018 at 04:44 AM

e6filmuser
Offline
• • • • • •
Upload & Sell: Off

p.1 #6 · p.1 #6 · Some Thoughts On Diffraction Blur

charlyw wrote:
Sorry, what you write is absolute physical nonsense. Diffraction is an optical phenomenon - thus no electrons far and wide...

Quite right. A slip of the mind. I wrote electrons when I meant photons. Edited. I know the difference.

Harold

Feb 20, 2018 at 04:55 AM

e6filmuser
Offline
• • • • • •
Upload & Sell: Off

p.1 #7 · p.1 #7 · Some Thoughts On Diffraction Blur

alundeb wrote:
Yes, it does not affect diffraction.

Thanks, Any details?

Harold

Feb 20, 2018 at 05:03 AM

alundeb
Offline
• • • • •
Upload & Sell: Off

p.1 #8 · p.1 #8 · Some Thoughts On Diffraction Blur

e6filmuser wrote:
Thanks, Any details?

Harold

The diffraction pattern is independent on the photon flux. It is kind of fascinating how each photon path (to the degree that we can record that) gets bent in a random way with a given probalility that follows the statistical distribution of many photons. The statistical distribution does not change depending on how "crowded" it gets.

Feb 20, 2018 at 05:17 AM

e6filmuser
Offline
• • • • • •
Upload & Sell: Off

p.1 #9 · p.1 #9 · Some Thoughts On Diffraction Blur

alundeb wrote:
The diffraction pattern is independent on the photon flux. It is kind of fascinating how each photon path (to the degree that we can record that) gets bent in a random way with a given probalility that follows the statistical distribution of many photons. The statistical distribution does not change depending on how "crowded" it gets.

Weird but very interesting. Thanks.

So what it bending those photon paths?

Harold

Feb 20, 2018 at 05:36 AM

charlyw
Offline
• • •
Upload & Sell: Off

p.1 #10 · p.1 #10 · Some Thoughts On Diffraction Blur

e6filmuser wrote:
So what it bending those photon paths?

The interaction of the light wave at the aperture edge. That forum thread you refer to is 10 years old - and isn't that easy to misunderstand but you managed it.

Feb 20, 2018 at 05:48 AM

alundeb
Offline
• • • • •
Upload & Sell: Off

p.1 #11 · p.1 #11 · Some Thoughts On Diffraction Blur

charlyw wrote:
The interaction of the light wave at the aperture edge. That forum thread you refer to is 10 years old - and isn't that easy to misunderstand but you managed it.

Diffraction is one area where we need the wave model of light to explain the phenomenon. The particle model does not explain it.

Feb 20, 2018 at 05:53 AM

Taylor Sherman
Offline
• • •
Upload & Sell: On

p.1 #12 · p.1 #12 · Some Thoughts On Diffraction Blur

I think you need to focus on refining the ether within the lens body.

/sarcasm

Feb 20, 2018 at 03:50 PM

LightShow
Offline
• • • • •
Upload & Sell: Off

p.1 #13 · p.1 #13 · Some Thoughts On Diffraction Blur

The Quantum Experiment that Broke Reality | Space Time | PBS Digital Studios:

Here is a demo of single slit and round aperture diffraction patterns, the round pattern is what happens to the PSF, and is what causes the softness, sunstars is sort of a combined effect of both.

Feb 21, 2018 at 03:58 AM


FM Forums \| Macro & Still Life \| Join Upload & Sell

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.