[ATM] Re: Have a trial formula for you, Abe-

["David Harbour" <scarab2@cox.net>]

Thanks for adding this, Richard.

Since the attenuation of light is so great in any case (with the sun) we are
only talking about a 30 minute of arc view; and since, if Abe wants to make
images of light bulbs, or other similar stuff, the coma and astigmatism
would not be visible because he is not magnifiying the image- thanks for all
of your help, Richard- And, vignetting: he seems to want to use lenses of
weak power, so we may be okay there.

Davey


----- Original Message ----- 
From: "Richard F.L.R. Snashall" <rflrs@rcn.com>
To: "David Harbour" <scarab2@cox.net>
Sent: Monday, May 09, 2005 6:24 AM
Subject: Re: Have a trial formula for you, Abe-


> David Harbour wrote:
>
> >
> > My good friend, *_Richard F.L.R. Snashall_* came up with a formula-
> > I'll convey your thanks to him for doing this. I hope it works out for
> > you. I am guessing that you will want to try a positive .25 diopter,
> > and a negative .25 diopter, If I read Richard right, here, with my
> > thick head. Good luck
> >
>
> I've thought about this a couple days.   The stronger the lenses, the
> closer they are set together -- and still closer yet given that the
> multiplier, (1-k)/k, has to be larger.  All of this means that the
> angle without vignetting is larger for stronger lenses.  The penalty
> paid is the sensitivity to distance and power.  This may impact
> your lens power decision.
>


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