This question comes from my previous question on fire. I have always felt that I have never come across a single photograph or video on fire that truly reproduces fire. Is that a problem with my visual perception or is it some aspect of fire that baffles cameras?
Speaking of fires, glowing flames like that of a candle is easy to study as there isn't much of dynamics in it. But studying the characteristics of an open flame like that of a campfire or the initial burning of a matchstick, requires high speed imaging. The images or videos of a flame look 'out of place' or unreal because most of the cameras used to shoot these videos have rolling shutters.
Rolling shutters work by reading out the sensor data, in rows, from top to bottom (or bottom to top) of the sensor. This causes a lot of distortion to fast movements.
For shooting undistorted videos, high speed cameras with global shutter are required. These sensors readout the entire image in one go, instead of reading it out in rows like that of a rolling shutter. But then again, high speed cameras with global shutter are extremely expensive.
And as for your final question, the luminosity of a fire keeps changing. This demands a huge variation of exposure and causes some problems while shooting. But as long as I have complete control of the camera, I don't see it as the camera getting baffled.
Very informative, JS. You have given me a detailed answer. Thanks for your time, and all the best.
Usually light from all parts of an object fall on both our eyes equally. But sometimes it happens that pinpoints of light from some parts fall on one eye but not on the other eye. Such objects appear as glittering to our us; at least that is what I understand.
I think the same phenomenon happens when we look at a fire, especially a natural one from burning woods etc.c (less for an electric one). But this does not happen with a photo: both eyes get the same image. I think this is main difference between photo and actual visualization of a fire. I think glittering objects do not truly glitter in a photo; we get such an impression because of psychological association about the glitter of that object.
Narayanan