Welcome to the NavList Message Boards.


A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Add Images & Files
    Re: Mylar Film as Artificial Horizon Windows
    From: Robin Stuart
    Date: 2011 Mar 15, 17:39 -0700

    The particular mylar used was actually the Baader Planetarium TurboFilm referred to in my post. It is specifically intended as an optical window. I obtained it from Woodland Hill’s Camera & Telescopes at the link http://telescopes.net/doc/2500/mftr/baader/item/TURBO Other types of mylar film may work too. In general thinner is better.

    The fogging that I mentioned in the post also happens with the plastic and glass windows supplied with the Davis artificial horizon but at a slower rate. I don’t it think would be advisable to apply anything (onion juice, saliva etc.) to the windows as this might affect its optical properties and hence the sextant altitude readings. It is probably better just to let the water equalize in temperature with the air before putting on the windows. (Of course this only works if the temperature is above freezing which it often wasn't around the time the observations were made). Alternatively one might substitute sump oil or mercury for the reflecting surface in which case fogging should not be a problem.

    Robin Stuart
    NavList message boards and member settings: www.fer3.com/NavList
    Members may optionally receive posts by email.
    To cancel email delivery, send a message to NoMail[at]fer3.com

    Browse Files

    Drop Files


    What is NavList?

    Join NavList

    (please, no nicknames or handles)
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.

    Email Settings

    Posting Code:

    Custom Index

    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site