Can you explain this photo to me?

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SUMMARY

The discussion revolves around the phenomenon of "red dot flare" observed in photos taken with smartphones, specifically the LG Tribute Dynasty and HTC Desire 530. Participants clarify that this effect is caused by internal reflections between the camera sensor and a glass surface, rather than lens flare. The red dot pattern is a diffraction pattern resulting from the sensor's pixel grid, which is typically arranged in a square. The conversation highlights the distinction between sensor flare and lens flare, providing insights into the optical behavior of smartphone cameras.

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I took this photo, which is of the flashlight on another phone, and I was just hoping someone could explain why it looks the way it does to me. (The pink circles, the blue half halo etc.)

Just in case the uploaded image doesn't load for you, here is a direct link to the image;

https://imageshack.com/i/pmVhj7QJj
 

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These are reflections off the internal components of the lens arrangement.

The light from the flashlight is casting so much light into the lens that it is lighting up the lens mounts as well as increasing reflections within the multiple lenses themselves.

Like this:
images?q=tbn:ANd9GcRl9WHoSiYytX5kz8vN27Ci64P2PXbz-WbbupGysnFwOjhy_2_v.jpg

but different angle, different lenses and different supports.
 

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DaveC426913 said:
These are reflections off the internal components of the lens arrangement.

Ah I figured it was nothing more than just something related to the phone's camera but wasn't positive. Thank you!
 
Eight red dots in a rectangle around the light source is typical for "red dot flare", which is a sensor flare, not lens flare. That is, it is due to internal reflection between the sensor and a glass surface on top of the sensor (probably the blur filter), not internal reflection between two surfaces inside a lens system. Both can be distinguished in this short youtube video, where the bright lamp revolves around the center of the image. The red dot pattern remains centered on the lamp and its rectangular frame does not rotate, because it corresponds to the grid of the sensor. In contrast, there are two lens flares in the video that do revolve around the center of the image, because they have to be on the diametral line through the lamp and the center of the image.

I am surprised you got the red dot pattern with a phone, which phone is it? On internet it seems to have been reported only for compact cameras.

The red dot pattern was particularly pretty when using a red laser as light source:
reddotflare.png
 

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spareine said:
Eight red dots in a rectangle around the light source is typical for "red dot flare", which is a sensor flare, not lens flare. That is, it is due to internal reflection between the sensor and a glass surface on top of the sensor (probably the blur filter), not internal reflection between two surfaces inside a lens system. Both can be distinguished in this short youtube video, where the bright lamp revolves around the center of the image. The red dot pattern remains centered on the lamp and its rectangular frame does not rotate, because it corresponds to the grid of the sensor. In contrast, there are two lens flares in the video that do revolve around the center of the image, because they have to be on the diametral line through the lamp and the center of the image.

I am surprised you got the red dot pattern with a phone, which phone is it? On internet it seems to have been reported only for compact cameras.

The red dot pattern was particularly pretty when using a red laser as light source:
View attachment 236605

Thanks for the very informative answer! As for the phones, the one shining the flashlight is the LG Tribute Dynasty, and the one I took the picture with is the HTC Desire 530.
 
You might still wonder what kind of reflection produces the dots in a rectangle centered on the light source. The light 'reflected' by the sensor is actually the diffraction pattern of the sensor grid. In a disassembled old camera it is easy to point a red laser at the sensor and see this diffraction pattern. If the pixel size on the sensor is ~2 μm, the angle of diffraction is ~20°. A glass cover plate (or blur filter) above the sensor reflects some of the light back to the sensor, resulting in an image with the red dot flare centered on the light source.

So the observation that the red dots on your photo are arranged in a square means the sensor has its pixels arranged in a square grid.
 
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spareine said:
Eight red dots in a rectangle around the light source is typical for "red dot flare", which is a sensor flare, not lens flare.
Thanks for that!
 

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