Re: [tech-3d] Digest Number 41

["Don Lopp" <dlopp@xxxxxxxxxxxxxxx>]

Miike thank you for taking the time to check me out Could you tell me what
the numbers would be for-- 75mm lens  for 75 feet to  with a i foot base,
100mmlens 100 feet to 3000 feet , one foot base and finally 135 mm lens -
135 fee to 4000ft with a one foot base ?
I realize that my symplistic plan would be worthless for close in stereo
such as when they tried to shoot stereo of tSports Illustrated models last
summer although common sense should have indicated  that itcould not be done
the way they attempted to do it allthough your system woul have indicated
whether there was a way they could do it . They were partially saved by
having some RBT 35mm cameras available though in my opinion the show
presented in Phoenix was , in my opinion,one of the lousiest 3D shows I have
ever seen at a NSA convention ( I am referring to the technical aspects of
the program -mostly too hyper). You are correct in assuming that I fine tune
my stereo base numbers based on previous experience such as any foreground
verticles or lack of foreground verticles or when verticles are only on
outer edges not in center( I believe that central verticles are not usefull
in my pictures- though not allways possible to avoid). A
----- Original Message -----
From: <tech-3d@xxxxxxxxxxx>
To: <tech-3d@xxxxxxxxxxx>
Sent: Monday, December 04, 2000 11:50 AM
Subject: [tech-3d] Digest Number 41


>
> There is 1 message in this issue.
>
> Topics in this digest:
>
>       1. Re: Stereo base calcuations
>            From: "Michael K. Davis" <zilch0@xxxxxxxxxxxx>
>
>
> ________________________________________________________________________
> ________________________________________________________________________
>
> Message: 1
>    Date: Sun, 03 Dec 2000 23:35:46 -0600
>    From: "Michael K. Davis" <zilch0@xxxxxxxxxxxx>
> Subject: Re: Stereo base calcuations
>
> Don,
>
> I ran your base calculation examples through the General Solution used by
> Bercovitz and others, to see what deviations they would produce.
>
> Here's what I got:
>
>  75mm lens with a 1-ft base,  75-ft Near and 3000-ft Far:  39.1% of MAOFD
> 100mm lens with a 1-ft base, 100-ft Near and 3000-ft Far:  29.1% of MAOFD
> 135mm lens with a 1-ft base, 135-ft Near and 3000-ft Far:  21.3% of MAOFD
>
> So, the longer your lens, the less OFD you produce, using this approach,
> and you're right - your images would all have less than maximum stereo
effect.
>
> Your method is very interesting and I can tell you are able to predict the
> results you'll get as long as your subject distances match the
> circumstances you describe.  When they don't, I suppose you are able to
> interpolate the base, relying on your experience.
>
> Thanks for sharing it!
>
> Mike
>
>
> >Date: Fri, 1 Dec 2000 22:39:19 -0800
> >From: "Don Lopp" <dlopp@xxxxxxxxxxxxxxx>
> >Subject: Re: Digest Number 36
> >
> >To Mike Davis reguarding stereo base- or 20 plus years I have been using
a
> >simple way of figuring out the stereo base for taking hyper scenics. For
a
> >135 mm lens I figure that the base of one foot gives me stereo depth of
135
> >feet to infinity or five times 135  gives me a stereo depth  of 675 feet
to
> >infinity. For a 75 mm lens , I figure a one foot base gives me  a stereo
> >depth of from  75 feet to infinity. For a 100 mm lens, a one foot base
gives
> >me a stereo depth of 100 feet to infinity and so on. For a 100 mm lens I
> >figure that infinity is any thing past 3,000 feet, or 30 times the near
> >point. I dont try to maximize the stereo effect in my pictues as some of
my
> >best ones have a deviation of less than one mm. My mental state because
of
> >my use of methadone and morphine is such that I can not handle any thing
> >very complicated and it has been some 6 months since I have been able to
> >take any serious scenics-may be next year ? DON
> >
>
>
>
>
> ________________________________________________________________________
> ________________________________________________________________________
>
>
>
>


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