Sometimes the people’s eyes are red in photos which makes the photo fail! Why do your eyes glow red in a photo? Is that because of the flash or because the photos were developed in a red-colored room? Or is there another reason?
Answer
Hi Matthias,
It’s actually very easy – the inside of your eye, the retina, is red. If the light source is close to the lens of the camera, as is usually the case with flash photography, the flash light hits the eye directly and is reflected back to the camera by the retina. So you look inside the eye, so to speak. That’s why you get those “red eyes”. You will never see this in photos taken without a flash, because there is no direct light entering the eye, nor if the flash is anywhere but close to the lens and aimed directly at the subject. That’s also why you have those big silver-colored flash umbrellas with the photographer – they provide indirect light through the walls of the room, so you don’t get red eyes with the photographer on your passport photo.
Nowadays, with digital photo editing programs, it’s easy to get rid of those red eyes. That immediately looks a lot less spooky.
Answered by
dr. Christophe Vande Velde
chemistry, organic chemistry, organic synthesis, materials science, organic electronics, crystallography, x-ray diffraction, structure-property relations, organic solar cells
Prinsstraat 13 2000 Antwerp
http://www.uantwerpen.be
.