Hello my name is Maddie.
I am doing my project on the effects of red eye. I have a few questions. I am deciding between; the subjects eye color, the angle the picture is taken at in relation to the eyes, or the lighting in the area for my variables. Which one do you think is the best? Do you have any other ideas? Also, depending on the variable you recommend, what would be the best way to conduct this experiment. Also, I was wondering if you know any good sites that I could use to conduct my research? My research is due very soon and I am out of ideas for sources. And, if I found a written article on red eye on the internet, what should i cite it as; an internet resource or an article. Thank you for your help. Do you have any tips or other knowledge of red eye that could be useful in my project??
consider the practical implications of your variables. If you choose eye color, you will need to come up with several different people to conduct your experiment. If you choose angle to eyes or ambient lighting, you only need one helper.
As for the internet resources on red-eye effect, I agree with you there aren't many useful sites out there. The Wikipedia article is the most organized one I could find, however it is not well referenced.
If the article you found has been published, e.g. it has a journal or book reference for itself, I think you can cite it as article. If all you have is its URL then it is an internet resource.
"red eye" effect in images usually originates from a flash. If the flash is close enough to the camera lens, then the light from the flash will enter the pupils of the subject and reflect off the blood vessels in the retina of the eyes and come back out the pupils and enter the camera lens. If you consider the similar isosceles triangles made by the flash pupil, camera lens and the smaller one in the eye, it is a matter of geometry to determine if the angle is such that the reflection can be seen by the camera lens.
The typical ways professional photographers prevent the "red eye" effect is to move the flash off camera (increase the base of the triangle) so the flash reflection of people looking directly at the camera doesn't make it back to the camera lens, have the subjects look at something like a helper so they are looking away from the camera/flash, bounce the flash off the ceiling or wall, or eliminate the flash and use ambient lighting.
The color of the iris has almost nothing to do it; however, the size of the pupil (dark ambient causes big pupils which increases the placements where red-eye occurs)
Unfortunately, if the subject is looking directly at the midpoint between the flash and the camer lens, they maximize the chance of "red eye".
If you don't have a camera with a separate flash, you will be limited in what you can investigate.
