From: chaloux@mandolin.mitre.org (Dave Chaloux)
Subject: Some random thoughts for the New Year
Reply-To: chaloux@mandolin.mitre.org (Dave Chaloux)
Organization: The MITRE Corporation, McLean, Va
Date: Thu, 31 Dec 1992 20:39:49 GMT

I have been accumulating a number of thoughts about some articles that
have appeared as well as some thoughts for new articles of my own.
Instead of posting them as separate articles I thought I would combine
them. That way, people who can't stand the fact I spell nucleus as
"nucleas" can hit the next key just once.

1) About Celestron Ultima 8x56 binoculars: You may recall that I did
some comparing of binoculars such as Nikon's, Aus Jena 7x50 and 10x50s,
and the Ultimas before I bought my pair of Ultimas. These were criticized
recently for having shorter eye relief than advertized. The comment was
accurate but possibly misleading. Specifically it was based on measuring
the eye relief with the eyecups left up. However, despite the fact the
eyecups are of somewhat harder rubber than normal, they will roll back.
I wear glasses and must do so to reach focus at infinity with these
binoculars. I use them quite comfortably with my glasses.

2) A comment on 7mm exit pupils. I already have made my view known that
small exit pupils are not such a bad thing. I now want to make clear
I don't think 7mm exit pupils or even larger are a bad thing either. As I have
stated before, I think exit pupil is a sacred cow that should be sacrificed
from time to time. It is true that in most conditions and with some people all
conditions some of the 7mm is wasted. But look at it this way. With some
people in some conditions it is not. By having the excess you are insured that
for the conditions you are working in, you have the largest effective objective
possible for you at that magnification. I have a 40mm University Optics 7-70
that I used with my 20" F5. If you figure it out that is an 8mm exit pupil.
Although 8mm on a binocular would be a waste there is a purpose for it on the
scope. Specifically, that eyepiece has the largest real field of view that I
have come across. I sacrifice a little aperture but so what. I can get all
7 of the main Pleiades in view at once.

3) A hint about calculating exit pupils. Exit pupil = focal length of eyepiece
divided by focal length of telescope. 40/5 = 8mm.

4) I have created for myself a database that I use for recording my
observations. It is linked to the SAC52 database as well. I have entered
all of my observations through May of this year so far. This has been a
large effort but has already paid some dividends. For one thing it is easy
to pull up all my observations on a particular object or class of objects.
For example I had thought that M 99 was the last Messier Object I
observed. It turns out that I had observed M 101 but was not absolutely
positive I had actually seen it at the time (but pretty sure). I then
(re)observed M 101 later. Thus M 101 is in the running for that distinction.

I had been using a program called NGP for this but I was unhappy about the
inability to enter non-NGC objects. I was also unhappy with the kinds of
information you can key on. I now have fields for such things as the kind of
instrument used, the difficulty of the object, the transparency and seeing
conditions, etc. I can very easily make queries based on those items. For
example, using NGP I would not enter objects that I looked for but did not
see because it would give me a false count of the total seen to date. I now
enter them because I can still get at the correct total easily.

I have done this in Paradox. If you have been thinking about doing this sort
of thing, I would encourage it.

5) Recording observations: If you do not keep records of your observations,
I strongly recommend doing it at least occasionally. In my opinion it helps
train the eye to see more. A planetary nebula that you had dismissed as
simply round with a bright central star might in fact be slightly eliptical or
annular, things you might not have noticed, etc.

6) I have been using paper to record my observations. For Christmas my wife gave
me a small microcassette recorder. This looks to be a much superior way of
doing things. (No turning on the red light to write). Even though my red light
was very red and very dim, it did affect my night vision and was a headache to
leave the scope, write, go back to the scope etc. I am going to miss my
spiral bound notebooks to some extent and will still keep one handy for drawing.

7) I have been thinking that some kind of project might be fun as a group for
the Net. Two possible projects come to mind.

A) Some way of having people rate the telescopes that they have used. This
might be helpful for people trying to decide what to buy. Are Meade owners
happier than Celestron owners? Vice Versa? We all have opinions but we
maybe could come up with a way of pooling our individual experiences. For
example, I was happy with my Meade for years but only after I replaced the
original optics.

B) We could pool observations and make some kind of observing handbook. Some
obvious possibilities are Messier Objects, Herschel objects, or Constellations.
My gut feeling is that individual constellations might work best to start. The
other projects are to large for a first cut. Another possibility might be
observations of Mars this opposition.

A Happy New Year to all and clear skies.