<p>This effect is called <a href="https://en.wikipedia.org/wiki/Vignetting" rel="noreferrer">vignetting</a>. The cases you talk about are specifically natural and pixel vignetting as explained on the wiki page. Digital cameras compensate these effects, but optical vignetting has to be done in image software for DSLR's with interchangeable lenses. For example if you import an image to Lightroom, there's "lens correction" option, which removes vignetting, distortion and chromatic aberration caused by the lens based on the lens profile.</p>

CC BY-SA 3.0
2017-03-24T20:08:14.883Z
Yeah, I've read that article. But does this phenomenon occur if we consider idealized film? Where there is no shadowing by the pixel sensor edges and no attenuation due to nonzero color filers thickness. I'm asking about phenomenon caused just be geometry.
ciechowoj
CC BY-SA 3.0
2017-03-27T03:26:20.610Z
Yes, that's the "natural vignetting" on the wiki page
JarkkoL
CC BY-SA 3.0
2017-03-24T13:50:31.327Z
2017-03-24T13:50:31.327Z
JarkkoL
<p>Consider hypothetical camera with pinhole (in mathematical sense) lens and is sensor, like in below image. Is it the case that the central region of the sensor will receive more light (pixels will be brighter) than the pixels closer to the border?</p>

<p>Will the darkening be proportional to the cosine of the sensor normal and the direction which the light comes from?</p>

<p>Is this phenomenon occurring in digital cameras, is it corrected digitally?</p>

<p><a href="https://i.sstatic.net/ALd2E.jpg" rel="noreferrer"><img src="https://i.sstatic.net/ALd2E.jpg" alt="enter image description here"></a></p>

<p>EDIT:</p>

<p>I mostly interested in case of idealized film. Digital cameras exhibit this effect due to light attenuation caused be some participating media.
I'm asking about pure geometrical effect like in Lambertian law.</p>

CC BY-SA 3.0
2017-03-24T01:46:08.027Z
You will see circles, due to diffraction
Milo Lu
CC BY-SA 3.0
2017-03-24T20:41:42.987Z
What if we assume infinitesimal pinhole and classic optics (no diffraction).
ciechowoj
<raytracing><lighting>
Amount of light reaching the sensor of pinhole camera model
ciechowoj
# Amount of light reaching the sensor of pinhole camera model

(Asked by: username_0 on 2017-03-23)

Consider hypothetical camera with pinhole (in mathematical sense) lens and is sensor, like in below image. Is it the case that the central region of the sensor will receive more light (pixels will be brighter) than the pixels closer to the border?

Will the darkening be proportional to the cosine of the sensor normal and the direction which the light comes from?

Is this phenomenon occurring in digital cameras, is it corrected digitally?

[![enter image description here](https://i.sstatic.net/ALd2E.jpg)](https://i.sstatic.net/ALd2E.jpg)

EDIT:

I mostly interested in case of idealized film. Digital cameras exhibit this effect due to light attenuation caused be some participating media.
I'm asking about pure geometrical effect like in Lambertian law.

**Tags:** raytracing, lighting

> **Comments:**
> **username_1**: You will see circles, due to diffraction  
> **username_0**: What if we assume infinitesimal pinhole and classic optics (no diffraction).  

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## 1 answers

### Answer by username_2 on 2017-03-24. Score: 5 | Accepted answer

This effect is called [vignetting](https://en.wikipedia.org/wiki/Vignetting). The cases you talk about are specifically natural and pixel vignetting as explained on the wiki page. Digital cameras compensate these effects, but optical vignetting has to be done in image software for DSLR's with interchangeable lenses. For example if you import an image to Lightroom, there's "lens correction" option, which removes vignetting, distortion and chromatic aberration caused by the lens based on the lens profile.

> **Comments:**
> **username_0**: Yeah, I've read that article. But does this phenomenon occur if we consider idealized film? Where there is no shadowing by the pixel sensor edges and no attenuation due to nonzero color filers thickness. I'm asking about phenomenon caused just be geometry.  
> **username_2**: Yes, that's the "natural vignetting" on the wiki page  

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