Re: flash, cross-viewing

[fj834@xxxxxxxxxxxxxxxxxxxxx (Dr. George A. Themelis)]

>I also can not cross eye view...
>I have tried holding it close and moving it
>back, however as soon as I focus the image inverts.
 
Holding the pair close is the wrong way to try cross viewing.  You should
hold the pair far away and focus the eyes close, perhaps by holding the tip
of a pencil so when you look at it with each eye, it projects in the each
of the two photos (with right eye projects in left photo, etc.)

Guide number:  If your flash has a dial for manual operation, the guide
number is equal to the product of the aperture times the recommended
distance.  Every time you change the aperture by one f-stop then you can
double or cut in half the distance.


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