Re: [photo-3d] Camera separation in stereo photography

["don lopp" <dlopp@xxxxxxxxxxxxxxx>]

As rguards to a 6 shot Rolleidoscope I would be glad to show you how but I d
on't know how to do it via email and it appears I am to late for Messa which
is the story of my life of late . Don
----- Original Message -----
From: "don lopp" <dlopp@xxxxxxxxxxxxxxx>
To: <photo-3d@xxxxxxxxxxx>
Sent: Tuesday, June 27, 2000 10:12 PM
Subject: Re: [photo-3d] Camera separation in stereo photography


> I think Where I get lost is the deviation  of 2.5 mm which is much more
than
> I can handle . I have never worried about deviatin before and when the
Bill
> G thing came up I suggested that 18 feet was as close as he could  shoot
> with 43mm lenses someone called in and said the correct amswer was 8 feet.
> Well I have shot with 45 mm lenses and 18 feet was the closest I could
> handle and I have since measured some of my older slides and I was hard
> pressd to find any with more than 1.5mm dev. I then made  guage to measure
> some more and got the same results--like I said before , mine shood look
> awfull flat ,but I have not heard any complaints except for one time when
> the closest thing was probably 150 feet. I found plenty , that looked
great
> with 1mm deviation. Way back when Joel was kind enough  to send guages
> around but I didnt take one as I did not see a need for one. Apparently my
> mistake. Don. Incidentall my wife says I can go to Messa but I am probably
> too late unless Someone is kind enough to share aroom like I have done at4
> other conventions where we had 5 to 7 in aroom some sleeping on the floor
> which is no problem. This typing sure wears me out as you can see- old
age..
> Don.
> ----- Original Message -----
> From: "Greg Erker" <erker@xxxxxxxxxxxxxx>
> To: <photo-3d@xxxxxxxxxxx>
> Sent: Monday, June 26, 2000 1:03 PM
> Subject: Re: [photo-3d] Camera separation in stereo photography
>
>
> >
> > >>Back to basics 101 -- I believe that the 1:30 rule only applies
> > >>when using 35 mm lenses Don.
> > >
> > >  I believe it applies any time the viewing
> > >FL matches the taking FL.
> > >
> > >  I wish John B. were here to make sure
> > >I'm not spreading errors, but I'm pretty
> > >sure I understand this correctly.  If Tom
> > >or George and anyone else wants to correct
> > >me feel free.
> >
> >   I just did some playing with the MAOFD
> > spreadsheet that John B. created.  The
> > comments say:
> >      "Bercovitz & Spicer's formula to limit
> >       maximum on-film deviation by limiting
> >       stereobase.
> >       The on-film deviation should not exceed
> >       one thirtieth of the focal length of the
> >       stereo system.
> >       The effective focal length of the camera
> >       lens should match the stereoviewer's focal
> >       length."
> >
> >   So if I use a 35mm lens the desired OFD is 1.17mm
> > (35/30). If I use 7' (2.13 metres) as the near distance
> > and infinity (999 metres) as the far, the spreadsheet
> > says the "maximum allowable stereobase" is 70.4mm.
> > Just like a Realist. (Note: this is assuming I am
> > viewing with a 35mm viewer lens which most of us
> > don't have).
> >
> >   For a Sputnik the lens is 75mm so the desired OFD
> > is 2.5 mm. If I use the same near and far distances
> > the spreadsheet gives the max stereobase as 69.9 mm.
> > Basically the same as the Realist case. (Note: this
> > assumes I am viewing with 75mm lenses).
> >
> >   Both of these match the 1:30 rule. 30 times 70mm
> > = 2.1m which is 7'.
> >
> >   BUT: if you change my taking FL without changing my
> > viewing FL then you get different results.  If I shoot
> > with a 135mm lens and still view with the 35mm lens
> > my OFD remains at 1.17mm but now the spreadsheet
> > gives a max stereobase of 17mm, for the same 7' to
> > infinity shot.
> >
> >   Shooting with a 24mm wide angle lens with the same
> > near and far (but still viewing with 35mm) gives
> > max stereobase of 177 mm.
> >
> > My understanding (and I'm willing to be corrected) - Greg E.
> >
> >
> >
> >
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