[MF3D.FORUM:1331] Re: Larger aperture size for twin rig shots?

["Don Lopp" <dlopp@xxxxxxxxxxxxxxx>]

----- Original Message ----- 
From: "Greg Erler" <greg.erker@xxxxxxxx>
To: "Medium Format 3D Photography" <MF3D.Forum@xxxxxxxxxxxxx>
Sent: Sunday, November 12, 2000 8:23 PM
Subject: [MF3D.FORUM:1330] Re: Larger aperture size for twin rig shots?


>   I'm just going to simplify.
> 
>   If you build a stereo camera and want the in-camera stereo
> window to be at 7' or so you need to move the lenses together
> by (roughly?) the on film deviation amount.
> 
>   So 2.5 or 2.7 mm closer together than the film gates should do
> it.
> 
>   With separate cameras (aimed parallel) the "in-camera
> window" is at infinity. So you waste the same 2.5 or 2.7mm
> to mount them with a 7' stereo window.
> 
>   Thus with 55mm film gates you should be able to still
> have 55-1.35mm or so of usable area. Any non-parallel aiming
> of the cameras could easily waste 1mm or more so that might
> be a bigger effect.
> 
>   Stereo base shouldn't matter if you keep the OFD under
> control.
> 
> Greg E.
> 
> ----- Original Message ----- 
> From: "Paul Talbot" <ptww@xxxxxxxxx>
> To: "Medium Format 3D Photography" <MF3D.Forum@xxxxxxxxxxxxx>
> Sent: Saturday, November 11, 2000 8:55 AM
> Subject: [MF3D.FORUM:1328] Larger aperture size for twin rig shots?
> 
> 
> > There has been some discussion here in the past about
> > the possibility of a larger aperture size 80x132
> > mount for images from dual camera hypers.  Last night
> > I was mounting a test shot taken with two MF (stereo)
> > cameras on a bar.  I was amazed at how little room
> > there was (in the 50mm aperture size mounts) for
> > horizontal cropping of the hyper image, while keeping
> > the stereo window in front of the scene.
> > 
> > The non-overlap area of twin camera shots really uses
> > up a lot of the excess image area.  I haven't done any
> > calculations to nail down specifics, but perhaps someone
> > here could run a few numbers.  Assuming a 75mm FL lens,
> > what is the widest aperture size that can be used to
> > properly mount images assuming the image area on film
> > is a) 55mm wide; b) 60mm wide; c) 65mm wide and the
> > stereo base is a) 6 inches; b) 12 inches; c) 24 inches?
> > 
> > If no one is feeling ambitious enough to run all those
> > numbers, how about one or two combinations and the formula
> > to calculate the rest?  A spreadsheet would be nice.  ;-)
> > 
> > Paul Talbot
> > 
> 
>