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Tel
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Reged: 03/31/06
Posts: 3965
Loc: Wallingford England
Re: Hyperion Zoom with FL Reducer on 8 SE
      07/03/09 09:06 PM

Hi cfraser,

Peter9 has just pointed out to me quite rightly, that in fact the 50 degrees AFOV on these EPs applies to the longer focal length 24mm and 20mm sections of this Zoom ocular. The shorter focal lengths give the wider AFOVs: i.e. 68.5 degrees.

Thus the following figures should now apply to your 8SE with your 6.3FR in place :

24mm : AFOV 50/ Mag.X53 = TFOV 0.94 deg. or 56 arcmins.
20mm: AFOV 50/ Mag.X64 = TFOV 0.78 deg. or 47 arcmins.
16mm: AFOV 68/ Mag.X80 = TFOV 0.85 deg. or 51 arcmins.
12mm: AFOV 68/ Mag.X107= TFOV 0.64 deg. or 38 arcmins.
8mm: AFOV 68/ Mag.X160= TFOV 0.43 deg. or 26 arcmins.

To give you some kind of comparison, remember that the moon is approximately 0.5 deg. or 30 arcmins in diameter.

Here also is a link which provides some data and reviews relevant to the Hyperion Zoom.

http://www.birdforum.net/showthread.php?t=73147

Hope this helps a little further and apologies for the error in my AFOV assumptions.

Best regards,
Tel

--------------------
Truth is the cubed root of Verbosity.



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Entire thread
Subject Posted by Posted on
* Hyperion Zoom with FL Reducer on 8 SE cfraser 07/03/09 02:00 PM
. * Re: Hyperion Zoom with FL Reducer on 8 SE Fogboundturtle   07/03/09 02:07 PM
. * Re: Hyperion Zoom with FL Reducer on 8 SE Tel   07/03/09 03:39 PM
. * Re: Hyperion Zoom with FL Reducer on 8 SE Bob Griffiths   07/03/09 04:17 PM
. * Re: Hyperion Zoom with FL Reducer on 8 SE Tel   07/03/09 09:16 PM
. * Re: Hyperion Zoom with FL Reducer on 8 SE cfraser   07/03/09 05:34 PM
. * Re: Hyperion Zoom with FL Reducer on 8 SE Tel   07/03/09 09:06 PM
. * Re: Hyperion Zoom with FL Reducer on 8 SE cfraser   07/03/09 09:26 PM
. * Re: Hyperion Zoom with FL Reducer on 8 SE ibase   07/04/09 04:31 AM
. * Re: Hyperion Zoom with FL Reducer on 8 SE Bob Griffiths   07/04/09 10:01 AM
. * Re: Hyperion Zoom with FL Reducer on 8 SE cfraser   07/04/09 02:02 PM
. * Re: Hyperion Zoom with FL Reducer on 8 SE cfraser   07/03/09 03:25 PM

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