Re: [photo-3d] ???? Re: AF Cameras for Stereo

[Herbert C Maxey <bmaxey1@xxxxxxxx>]

>>Indeed I'm afraid active-autofocus cameras can cross-read reference 
>>beams, yielding to TOO gross focus mismatch. 
>>But this is a fear of my own, and I will be glad to know if somebody 
>>experienced such an inconvenience.

The simple fact is that autofocus cameras, side by side are not reading
the same area. Please, then...explain how they can guarantee exact focus.
Please also explain "Cross Read Reference Beams"? I assume from your
comment "Fear of my own ....." that you have not actually tested this? 

I understand the idea of camera manufacturers setting focus for each lens
differently. I am away of the cameras mentioned - granted, I have never
used either of them. I know they were not popular as the Realist, and I
also know what the representatives for Realist had to say about this
system. Realist stopped building cameras in part, due to the
unavailability of quality optics that were matched. I am sure that
twinned cameras - or at least camera guts merget together like the RBT
are great. Doesn't Dr. T use this type of camera? 

>>P.S. I prefer manual settings, so I usually use stereo cameras. 
>>but sometimes one needs a broader stereo-base, and full manual 
>>settings would hobble the use of paired cameras to non-action 
>>pics.    

But the above happens rarely (I am not sure what you mean). I have used
pared cameras. I also shoot gems and minerals, and the need for twinned
cameras has never arisen - I use a Slide Bar for this work. In 30 years
of Stereo Photography, the need for an extended stereo base has virtually
never arisen. Extending the Stereo Base presents problems also.

As for action pictures, I can shoot action just fine with my Realist, and
a fast shutter speed is not usually required as much as many people
believe. It is a matter of proper panning, catching action at the right
time. However, action is not what I shoot.

I know why paired cameras are used - it is because there are not that
many stereo cameras available, or people want to try stereo without
buying a camera such as a Realist. I still will maintain to my dying
days, that nothing beats a Realist for stereo photography in its
construction, lens quality and ability to create great stereo images.
Twin Cameras are OK, but far more of a hassle than using a purpose built
Stereo Camera.

BOB