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RE: [APML] Optics Question

To: "'Wei-Hao Wang'" <whwang@gmail.com>, "'Discussion of Film Astrophotography'" <astro-photo@seds.org>
Subject: RE: [APML] Optics Question
From: "Thomas W. Earle" <twade@bmi.net>
Date: Fri, 7 Jan 2005 23:52:52 -0800
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Wei-Hao,

Excellent explanation!  I completely forgot about how the extra
focal length is "spreading the light"; hence, even though the
FSQ-106N has 2X the light gathering power, this light is being
spread over 2/3 more focal length which results in a slower system.

I really appreciate your time and expertise.

Wade


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References:
- Re: [APML] Optics Question
  - From: Wei-Hao Wang <whwang@gmail.com>

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