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    Re: LED conversion Astra IIIB
    From: Rommel John Miller
    Date: 2016 Aug 18, 23:34 -0400

    This is precisely why I feel it imperative that I go to sea and far enough from land and light pollution in the very near future to experience pure night blindness as I once experienced it in the Navy.  I just turned 58 on 17AUG this year and I genuinely want to see the relevance of artificial light on this phenomena.  I also would like to see the night sky quite possibly as it was seen when the first cognizant being on earth looked up to the stars and recognized them as they are.  My experience with cancer of the prostate is confined to the prostate so radiation is my next option even though in the back of my mind I still think this cancer might very well take me.  My request is my one bucket list item.  To just go to sea and to practice cn  out in the middle of the ocean and to learn and be open to learning.  I only ask for a rack and food etc.  And the ability to work and learn.  I am sorry to sound so needy and desperate but I feel this group is my only hope.  Thank you.

    Rommel


    On Aug 18, 2016 4:30 PM, "Stephen Wawrzyniec" <NoReply_Wawrzyniec@fer3.com> wrote:

    If you are shooting in astronomical twilight I dont think red is critical, there is still ambient light. If you felt the need to do a 1:00a.m. site it would help. I'm 58 now so my vision is not anything what it was and the white LED I'm using in my sextant is an ultrabright. Being able to see the scale especially on the vernier far outwieghs diminished night vision. But the problem with the IIIB is the design of the clear plastic not the light. I work in a lab so I coated much of it with evaporated aluminum in an effort to direct the light better toward the scale, I had to remove much of it becuase where that plastic is intended to direct the light simply does not work. I used a red LED first, ended up switching to white, not so much from lack of intensity, there's just not light well directed to the lower part of the vernier scale so getting minutes is hard down there, the eye is more sensitive to the white. I stiil find it annoynig at the lower paer tof the scale though, tat and where the metal cover allows light to pass to no good use except that it occasioanlly finds a direct path to the eye, then regardless of color you are temporarily blind.

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