P3D Re: Macro (Re: Andrea PH2652)

[roberts@xxxxxxxxxxxxxxxxx (John W Roberts)]

>Date: Mon, 30 Mar 1998 09:39:59 -0700
>From: Eric Goldstein <egoldste@xxxxxx>
>Subject: P3D Re: Macro (Re: Andrea PH2652)

>George Skelly (Hyponar) wrote:

>> Regardless of where the camera is placed along the bar,
>> the angular displacement is always the same.

>Thing is, as was mentioned just a couple of posts ago, some subjects
>seem to call for more displacement and others for less, depending
>specifically upon what you are shooting and not just how big it is or
>how far away from it you are. Macro/micro stereo displacement is truly a
>"subjective" or subject-dependent situation, and no formula or
>mechanical solution will substitute for judgement and experience...

Of course, if you always shoot very similar subjects, once you have a pretty
good rule established, it might be nice to be able to partially automate
the setting of the interocular. In any event, it would be interesting to
view the results of a photo taken with this device.

I had a different concern - from the description, it sounds like the two
views are always toed in. As was pointed out recently, sometimes you can
get away with converging views, but sometimes the amount of keystone
distortion they introduce is objectionable. If I were planning to take a
toed-in macro, I would be inclined to put the point of convergence at the
back (furthest point) of the subject (or further), which with this
device would mean that the nearest point of the subject would be closer
than the pivot point. Might this affect the apparent displacement, etc.?

John R


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