NavList:

   

Reply

Speaking as a photographer, there's a lot to be said for a variable
polarizing filter.  OTOH, most good sextants have filters that are
effective at dimming glare along the horizon, below the sun.  I
wouldn't go out of my way for just this feature.

As to a 10x scope... nah.  Even the 7x monocular I use with my Plath,
in all but the calmest of conditions, is a challenge from the deck of
a heavy displacement (ca. 12 tons with a full load of fuel and water)
35' boat.  The inverted image has its value, I suppose, but it adds a
level of complication not worth undertaking.

Stick with a good uninverted 3x scope on a good sextant and all will
be well.

Cheers,
Rick Emerson

On Jan 13, 9:56�pm, Alexandre E Eremenko 
wrote:
> My esperience with polarized shades (on a Simex
> horizon glass) shows that
> one ordinary operation is impossible with these shades:
> I mean determination of the index error by measuring
> Sun's semidiameter. Unless you have an eyescope filter,
> of course. As I understand, all modern sextants come without
> this filter.
> On the other hand, this method of finding the index error
> seems to me the most accurate and
> most practical of all methods.
>
> Alex.
>
> On Tue, 13 Jan 2009, Mike Burkes wrote:
>
> > Yes, speaking of limited range,the Simex does not lend itself in 
determining index error via superimposing the Suns(arc set to 0),the index 
filter having insufficient polarization therefore don't!> From: 
frankr...@HistoricalAtlas.com> To: NavList@fer3.com> Subject: [NavList 7021] 
Re: Simex Mariner Polarized Shades...How Well Do They Work/10X Inverting 
Scope> Date: Mon, 12 Jan 2009 18:15:10 -0800> > > I agree with Mike. The 
polarized shades are effective (I have a sextant similar to the Simex) and, 
as he said, they let you "dial in" a precise amount of shading. They do have 
a limited overall range, and this can occasionally be a minor nuisance. As 
for star sights, unless I am mistaken, the polarizers on the Simex can be 
rotated out of the optical path, just like the shades on other sextants. The 
7x35 scope is sufficient for all purposes. If you buy a sextant on ebay with 
extra scopes that you really don't need, consider selling the scopes 
separately. They usually fetch a good price.> > -FER> > > 
_________________________________________________________________
> > Windows Live� Hotmail�: Chat. Store. Share. Do more with mail.
> >http://windowslive.com/howitworks?ocid=TXT_TAGLM_WL_t1_hm_justgotbett...
>
>
--~--~---------~--~----~------------~-------~--~----~
Navigation List archive: www.fer3.com/arc
To post, email NavList@fer3.com
To , email NavList-@fer3.com
-~----------~----~----~----~------~----~------~--~---

   

Reply