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Re: [PSUBS-MAILIST] my optronic mast idea with sketch
How do you keep from getting sick as you bob up and down under the surface looking through the little scope?
------Original Message------
From: Jon Wallace
Sender: owner-personal_submersibles@psubs.org
To: personal_submersibles@psubs.org
ReplyTo: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] my optronic mast idea with sketch
Sent: Feb 6, 2010 11:53 AM
An optical periscope is nothing more than a refracting telescope,
although military models have ranging and hash-marks for direction
indication embedded within the optical train. As Jens has suggested, a
good optical periscope/telescope requires excellent optics and accuracy
in construction. You'll need to match the focal length of the primary
lens to the length of the tube you want or you won't be able to focus
the image. You'll need a compound primary lens to counter chromatic
aberration, and hi quality lenses throughout the optical train to
counter spherical aberration. You'd be surprised of how soon you tire
of viewing multicolored and distorted images terrestrial objects. Good
refractor type lenses are expensive which is why the vast majority of
telescopes in the world, both research and amateur, are reflectors
(mirror primary).
Unless you really want to build such a periscope for the sake of the
challenge or "just because" (perfectly valid reasons in my opinion), it
doesn't make financial or practical sense given the proliferation of
very good quality, and cheap, digital cameras that can easily be housed
in home-built water proof containers. A $300 eight inch screen NETbook
with a few web cams attached to it is the way to go here. You can even
record the entire dive directly on the netbook.
But again, for someone who just wants to meet the challenge of building
an optical periscope, internet research on building refracting
telescopes will provide you all the information you need.
Jon
Jens Laland wrote:
> Brian
>
> An optical periscope is actually a rather complicated and accurately built
> instrument, see the US Navy WWII Submarine Periscope Manual, at
>
>
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