P3D Re: S1 Ambient flash

["Dr. George A. Themelis" <DrT-3d@xxxxxxxxxxxxxxxxxxxxxxxxxxx>]

>Thanks for the S1 flash review George. Dr T explains how the S1 exposes
>available light to lighten the background before firing the flash to
>properly expose the subject. I'm surprised many are so amazed by this
>discovery :-) This technology/ feature has been employed in P&S cameras
>since the early 80's. 

Thanks Mark!

Somehow I was afraid I had missed 20 years of camera technology! :-)
Still, it came as a revelation to me when seeing it used by a stereo
camera.

I was expecting some skepticism... For example:  Why would anyone want
exposure at f2.0 in stereo photography?

The bottom line is that this flash mode works very well if you anticipate
a few potential problems:  1. If there is ample light in the background 
then this will show up in the f2.0 exposure and it will be painfully out 
of focus.  2. If the ambient light comes from fluorescent tubes then the 
picture will have an annoying green cast.

I see #2 most of the time in pictures at work and club meetings... I was
thinking of using FL filters in the camera and a light green filter in
the flash.

Another issue that I don't understand is how the system works in daylight
fill-in flash exposures?  For example, if the ambient exposure is f16
at 1/100 (full sun with 100 ASA film) and the flash needs f5.6 to put 
light in the foreground, what is the camera going to do?  Obviously, a 
second exposure at f5.6 will overexpose the background.  Any words of
wisdom on this?

George Themelis



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