Sunday, August 16, 2009
optical magnification measurement
optical magnification measurement
I was playing with a toy parabolic microphone and noting that it came with a little viewer/direction aid, and wondered if this was purely a tunnel or whether it actually magnified.
I looked at the horizon and moved the view up and down. This showed how the magnified horizon moved in the opposite direction, proving that things were being magnified.
The logic is that if 360 degrees is magnified say by 2, then is will take up 720 degrees, so that as you move your scope upwards the fixed horizon has to move downwards an equal amount.
This leads to an interesting method of checking the magnification, albeit very rough with just human eyesight. Obviously you need to have one eye looking through the lens and the other just normal vision to get an idea of the scales.
fun
cheers
martinW
I was playing with a toy parabolic microphone and noting that it came with a little viewer/direction aid, and wondered if this was purely a tunnel or whether it actually magnified.
I looked at the horizon and moved the view up and down. This showed how the magnified horizon moved in the opposite direction, proving that things were being magnified.
The logic is that if 360 degrees is magnified say by 2, then is will take up 720 degrees, so that as you move your scope upwards the fixed horizon has to move downwards an equal amount.
This leads to an interesting method of checking the magnification, albeit very rough with just human eyesight. Obviously you need to have one eye looking through the lens and the other just normal vision to get an idea of the scales.
fun
cheers
martinW
