[MF3D.FORUM:1718] Re: Using front shift to simulate camera movements?

["Don Lopp" <dlopp@xxxxxxxxxxxxxxx>]

This is where I give up how does one get a useable image when cameras are up
t 500 feet apart much less at 10, 20 ,30,40, 50, and 100 feet apart  ,how
about the minor alignment problems  much less the flair problems --What is
wrong with doing it the old fashon way  especially when they are more than 6
1/2 inches apart approximately -I see no need for mirrors except  when you
are trying  to use a interocular of less than 6 1/2 inches using a large
enough semi transparent mirror as I mentioned before.I hope I do not hear
any more about 2 cameras 500 feet apart viewing the same scene through 2 45
degree mirrors  ach de lieber  A 500 ft base with 80mm lenses would put the
near point-of 7 miles out toabout 200 mileswhic brings out all the problems
of haze curvatrure of the earth  etc and who no what else--my tens unit will
not let me continue  this nightmare scenario----DONint
----- Original Message -----
From: "Bill Glickman" <bglick@xxxxxxxx>
To: "Medium Format 3D Photography" <MF3D.Forum@xxxxxxxxxxxxx>
Sent: Monday, April 09, 2001 1:36 PM
Subject: [MF3D.FORUM:1632] Re: Using front shift to simulate camera
movements?


> Matt,
>
> > Two cameras can be mounted facing each other on an adjustable rail --
with
> a
> > small front-surface mirror mounted at a 45 degree angle in front of each
> lens.
> > This allows you to get both cameras quite close (limited by the size of
> the
> > mirrors), and allows easy access to the focusing and film advance
> mechanisms.
> > Matt
>
>         Thanks for the suggestion Matt.  Have you ever tried this before?
> How is the results?  I would assume the mirors would introduce some
> sharpness loss?   Also, how do you determine your interocular distances?
Is
> it the measurement between the center of the mirors?
>
>          This may be difficult since I am using range finders vs. SLR.
>
> Bill G
>
>
> >
> > Bill Glickman wrote:
> >
> > >       I am trying to develop a MF camera system that allows one to set
> > > interocular bases at any seperation without physical
limitations.....As
> we
> > > all know, this is physcially impossible sometimes with two non- shift
> > > cameras.  My idea was to use two cameras side by side, but each one
> would
> > > have the capability to shift the lens horizontally.   This has a very
> > > dramatic effect vs. spacing the cameras.  For example, I can simulate
> 24"
> > > interocular distance with only 3mm of front shift on one camera.  I
have
> > > tested this, it works.  So a small amount of lens shift would simulate
> > > interocular spacing fro 0 to 500 + ft.
> > >
> > >       I have found that myself and my audience all prefer very small
> OFD's,
> > > say 1.3mm, hence the need for bases much tigher than any two cameras
can
> > > every physically acheive.   A fixed stereo camera (sputnicks) don't
> appeal
> > > to me because I want the flexibility of adjusting the interocular
> distance
> > > when required.
> > >
> > >         Although this sounds good in theory, I am curious if this will
> > > produce the same stereo effect as utilizing two cameras at the proper
> > > interocular distance.  I don't plan to use it for excessive bases,
only
> for
> > > 24" and less.  Has anyone every tried this before?  Any input?
> > >
> > > Bill G
> >
> > --
> > ______ Matthew V. Ellsworth ______________________________
> >       oakridge@xxxxxxxxxxxxx      http://www.oak-ridge.com
> >
>
>