Re: [photo-3d] On achromatic stereoscopes....& Trans vs. Negs...

["Ferguson Studio" <larry@xxxxxxxxxxxxxxxxxx>]

Boris;

The Visual Survey Telebinocular is really fantastic, but it isn't portable
and it only works with the standard format 3.5x7" stereoview.  Also, it has
a nasty glare problem with flat views and I find myself constantly tilting
the view forward in the holder to get rid of it.   If you put one of my 4x7"
views into this machine you will really be able to see just how sharp they
are but you won't be able to view the entire image, heck, you can't really
see the corners in a 3.5x7" view either.

Why not try out one of the viewers that Harry Richards is selling.  A very
nice polished Lucite model that will fit into your pocket.  Everyone who has
one swears by them and everyone who doesn't have one wishes they did !  They
run $35 and $55 which is a 1/4 of what you will pay for a Telebinocular.

On another note, the perception that Transparencies are sharper or have a
longer tonality scale is a myth.  You must factor in size of the original
and degree of enlargement for sharpness and if you would just use a
densitometer you would see that the tonal scale of a good transparency is
about three f/stops whereas the tonality scale of a good BW print is about
seven.   Large 4x5" transparencies are in fact less sharp than small 35mm
trans and resolve fewer lines on resolution charts but their bigger size
makes them appear sharper because they require less degree of enlargement to
make bigger prints so when you enlarge them they are sharper!

If you would look at my 5x7" stereoview camera contact prints on my
stereocards (the ones who's ID numbers begin with #57-) under a 10X loupe
you would be amazed what you can see, both in terms of sharpness as well as
tonal separation that would beat the socks off your 35mm stuff.  That's why
I love a bigger stereocamera, so that I can enlarge an individual image to
20x24" and still have it be razor sharp-you can count every little hair on
her eyebrow.

By the way, how was the shooting with the twin-rig Hasselblad setup with
Betty?  When are we going to actually see a Boris print stereoview?

All my best to you;

Larry