P3D RBT Stereo Cameras

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

Mark Hatfield asked for information about our RBT cameras...

>I was so interested to learn that the two of you had independently purchased 
>different models(R3 and R4 I believe) of the RBT cameras. Now George I know 
>that you have had your S1 for, it seems, almost a year. I would like a little 
>more information on the particular cameras that you and Mark Dottle 
>purchased.... this might help me decide if an RBT should be in my future!

Yes, certainly.  I will try and summarize my experience with RBT cameras.
As you mentioned, I own an RBT S1 since November, but, a correction, Mark 
Dottle and myself bought the same camera, an RBT X4, recently.  Now, it is 
getting a bit confusing with the RBT model designations... There used to 
be an X2 (now called X2V2) and there is an X3, X4, the S1 and the 109.  
For pictures of these RBT cameras you can go to the 3-D Concepts web page 
(or elsewhere): www.stereoscopy.com/3d-concepts, or you can ask Jon Golden 
(3dman@xxxxxxxxxxx - currently on vacation) to send the appropriate 
literature.

Here is a handy Table:

RBT Model  Type         Cameras Joined   Lens Mount
---------  -----------  --------------   ------------
  X2V2     SLR-elect    Ricoh XR-X3000   Pentax K
  X3       SLR-elect    Ricoh XR-X3PF    Pentax K
  X4       SLR-manual   Cosena CS1       Pentax K
  109      SLR-elect    Yashica 109      Contax
  S1       Rangefinder  Konica Hexar     N/A

Here is how to navigate:  

- Do you want an SLR camera or a rangefinder camera?  
  If you want a rangefinder camera there is only one choice: S1.
  If you want an SLR camera then proceed:

- Do you want an SLR camera with a manual shutter or with an
  electric shutter?  If you want a manual shutter then there 
  is only one choice: X4.  If you want electrical shutter then
  proceed:

- Do you want a Pentax or Contax mount?  If you want a Contax
  mount, there is only one choice: 109.  If you want a Pentax
  mount then you have two choices:

- X3 or X2V2?  These are quite similar but the X3 has a few more
  features (like a pop-up flash) at a slightly higher price.

Now, I will try and explain what these questions mean and what
the consequences of rangefinder vs. SLR and manual vs. electrical
shutter or Contax vs. Pentax lenses are.

Let's start from the simple stuff... Contax vs. Pentax.  If you
buy the 109 camera then you have to start looking for Contax
bayonet lenses, including the high-quality Zeiss lenses.  If you
buy the Pentax mount cameras then you can be using the more
common (and lower priced) Pentax-mount lenses.

Suppose you decide to go with the Pentax mounts.  Should you get
the manual version (X4) or stick with the electrical shutters?
The manual version offers no automation.  You set the shutter
speed and aperture manually.  There is a through-the-lens
metering system to guide you for the correct exposure.  Film
advance and rewind is manual too.  There is a mechanical timer
and a hot shoe (flash synch is up to 1/125 s).  It is a very
simple camera.  The small battery powers the light meter.  The
shutters are mechanical (work without batteries).  As a result,
the camera is a bit more compact and lighter.  Currently,
the X4 is the least expensive RBT camera (I cannot use the
word "cheap" :-))

The automatic SLR cameras have a variety of advanced features
like different metering systems, auto film advance and rewind,
multiple exposures, depth of field preview... etc.  These features
come at an extra cost and weight.

The SLR RBT cameras can be used with any lenses that fit in the
mounts.  RBT offers linked zoom lenses for all their models.
The lenses have their three adjustments (focus, aperture,
zoom) linked externally via mechanical rods so that when you
turn one in one lens, the other one turns at the same time.
You can fairly quickly "break" the links and take the lenses
out and put another pair.  You can buy your own lenses and hope
to be matched (and then you have to adjust them independently
as you take pictures).

All SLR RBT cameras also come in two versions: either 75 mm
lens separation or 65 mm lens separation.  The 75 mm versions
give you a roll with 18 24x36mm (full frame) pairs that is 
compatible with commercial processing.  The 65 mm version
gives you more (20?) 24x33 mm pairs in a roll that is not
compatible with commercial processing (that means you have to
mount your own slide film or make your own prints).  Most people
go with the 75 mm version.  The only person I know of with the
65 mm version is DrDave and he has discussed the advantages of
this configuration from his point of view.

One warning to close this introduction:  RBT cameras are very
expensive for most people's standards.  And in terms of
reliability, the result of this custom work is necessarily 
LESS reliable than each commercially produced camera.  
Because they pay A LOT OF MONEY, some people expect PERFECTION 
in performance and reliability.  This is not going to happen.
So consider yourself lucky if you get a system that performs
flawlessly for many years to come.  If there are problems
these will be fixed for free under warranty or at the 
appropriate cost after the warranty has expired.  But don't
expect the reliability of modern commercially produced 
cameras we are all used to, no matter how much money you paid,
and be prepared to wait for a long time if the camera has to
be shipped back to Germany for repairs.

George Themelis