NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Eyesight dangers using telescopes
From: Bill B
Date: 2009 Jun 26, 06:58 -0400
From: Bill B
Date: 2009 Jun 26, 06:58 -0400
Engineer wrote: > Diplomacy on this site is not always in evidence (no, not you Frank). Douglas > I hope will continue to be a valued contributor. Can we perhaps all resolve to > use phrases such as "Are you perhaps mistaken?" as substitutes for more > direct and acerbic versions. I personally prefer the phrase uttered by Dabney Coleman's character in the film, "9 to 5." Something like, "I'll be damned if I'm going to let some snot-nosed punk let my cheese hang out to dry." It is pithy without being degenerate ;-) To Doug Seriously, I was a list newbie once with no clue, now I am semi-established member with no clue. When the veteran gurus tell you it is possible, "trust then verify." A new set of eyes thinking outside the established box may have something to add. A new member telling a lot of folks that can do star-to-star distances quite well that they cannot be done does not solicit a lot of sympathy for your inability. It has been pointed out in many posts that it is not easy, it takes practice, and there are techniques and tricks. The bait is out there, members are willing to share (it is the 90-% of the group exists) take the bait. In my case, a member that resided in the same town taught me many techniques and tricks. Sit, find something to steady body/elbow/arm etc. I could not do it well--if at all--at first. Baby steps. Start with bodies that allow you to hold the sextant in the vertical position. For more difficult observations take the scope off and eyeball one star then find the other star in the index mirror and get them close if not presetting based on calculations. Do that even with presets for awkward positions. That exercise also helps in developing a kinetic sense/memory of what contortions/circus-people positions you need to assume to make the observation. If preset find a dim object star in the horizon mirror with scope and the presumed other bright object star in the index mirror, then switch the stars/mirrors and see if they still align. Try Frank's tip for lunars. Get them close, relax and take a quick break. Get them closer and relax, then move in for the money shot. In star-to-star distances there is no rush or pressure as they are not changing angular distances in a hurry. Make several observations and average to reduce random error. It is very frustrating at first. Even with practice, the process can throw you a few curves. I watched a veteran upset because his sextant was minutes off before realizing he was viewing a wrong star for the designated pair in the winter hexagon. I have witnessed two observers with advanced degrees who should have known better sitting on the same side of a picnic table, leaning backwards to get the angle--which caused the center of gravity to shift so the table rolled over on them as they fell backwards. It was interesting that despite the fact both were falling on their backs and heads with a table on top of them they both came to rest in the same position--pinned under the table with the arm holding the sextant outstretched and vertical. No harm was done to the sextants. I would normally have found this humorous, but it took two trips through the washing machine to get the grass stains out of my jacket. Bill B. --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---