Re: [ATM] ATM: Please answer simple question, each and every one of you, please-

[Nils Olof Carlin <nilsolof.carlin@telia.com>]

>>>>
Now, here is a rule, that I have seen, for which it is claimed that it 
is, 
shall we say, "metaphorically" "set in concrete". And the rule is 
this:

(1): Odd number of reflections, image is reversed and inverted.

(2); Even number of reflections, image is correct but inverted.

This is for REAL  images, and not virtual images; it is for images 
that have 
been formed by a focusing objective mirror or lens, and then either 
had 
another single reflection, or not, or multiple reflections.

A simple yes or no will suffice. 
>>>>>

The last sentence is debatable ;-) 

For instance, when studying the reflections seen in a Newtonian when 
using an autocollimator, I found that after a grand total of 7 
reflections (counting reflections in the secondary), the real image of 
the primary's center spot, formed at the level of the primary, appears 
as if rotated by half a revolution (pi or 180 deg). This image is 
reflected back in the primary, and after another 7 reflections (making 
15) it is reflected to another real image, accurately on top of, and 
oriented as, its origin. 

"Appears as", that is - but whether this orientation means it has 
rotated by 180 deg (clockwise or anti-) or has been flipped (or instead 
reflected) first top-down, then left-right (or in opposite order) is a 
matter of philosophic speculation. I guess "image is reversed and 
inverted" could apply to precisely this situation. But the process 
applied once more will restore the image orientation to the original 
one.

http://web.telia.com/~u41105032/Acoll/Acoll.htm

BTW when you look at your image by an ordinary flat mirror, how come 
it appears reversed left-right but not top-bottom?

Wrong question. The image of you has its head up and feet down just 
like you have, its right arm to the right, its left arm to the left. It 
also faces the mirror just as you do - so, in fact, it isn't reversed 
at all.

Nils Olof
 




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