We live on a working farm, and our house is situated on a hill with a
view of the surrounding farm. We want something like a telescope to be
able to better monitor the goings-on. I don't know that "telescope" is
the right word for what we want.

We want to be able to *clearly* see things from about 600 feet up to a
mile away both during the day and at night.

We have binoculars, and even a night-vision goggle, but we're looking
for something that mounts on a stand - think of the viewers on top of
the Empire State building or Niagra falls. We don't need something
quite so sturdy as that, but we want to set it up on our (inside)
verandah so that we can walk over and peep through any time.

I can't yet give you a price range, because I honestly have no clue
what they cost. It needs to come from a company that ships from the
United States, and that does Internet business, as I can't drop into
an American store :-)

My husband says, "I want to be able to count the freckles on a man's
face at the end of the property."

I looked at the specs of the scopes in the links Bobbie7-ga sent in my
cancelled question (http://answers.google.com/answers/threadview?id=434662),
but I don't really understand "field of view" "objective" "prism type"
"pupil relief" etc.

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Clarification of Question by jennyinjamaica-ga on 17 Jan 2006 15:40 PST

Note: I don't actually want a commercial scenery viewer... I need
something high-powered like a telescope, but designed for terrestrial
viewing.

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Request for Question Clarification by palitoy-ga on 18 Jan 2006 06:15 PST

There are many different telescope solutions that I could suggest to
you but a lot depends on your price range, how big you wish the
telescope to be and where you are located.  Telescope manufacturers
notoriously charge more for the same telescopes if you are located
outside of the USA!

The comment by jh963-ga is a good one but the first paragraph needs
completing.  Telescopes meant for night-time viewing *do* generally
have the image upside down but that should not stop you from
purchasing one to use in the daytime as there is a simple adaptor you
can buy that flips the image to be correct.

I noticed you posted this question initially for Bobbie7-ga who did
not have the experience in this area to help you out.  I have been
using telescopes for over 10 years and had owned several different
types during this period.

If you require any further assistance I would be happy to help.

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Clarification of Question by jennyinjamaica-ga on 18 Jan 2006 19:35 PST

ok, as for where we are located: We live on a 380 acre farm in
Jamaica, West Indies. We want to view from our house, which is located
on a hill on the otherwise flat property. Not all of the property is
being worked. We have a sheep pen about 600 feet from the house, and
we've had problems with theft there. We put up a flood light, but want
to be able to check on the sheep at night. We have fish ponds that
extend about a mile from the house. We want to be able to see what's
going on at the ponds both during the day and at night.

Our bedroom is upstairs, and we have a glass-enclosed verandah that
has an excellent view of all of the working sections of the property.
We want to set up a scope on a stand/tripod, and be able to step over
any time to look around and see what's going on.

I have a United States address to which I can ship items. We don't
know how much we want to spend because we really don't know what it
costs. Is it US$300 or US$3000? I imagine it could be either, but a
lot will depend on how much detail we can see with the scope.

If you could give me a brief description of the various terms used on
the scope sites, it would help the decision process a lot.

Hello jennyinjamaica-ga,

Thank-you for your question, clarification and your request for brief
descriptions of the terms you will encounter whilst trying to choose a
telescope to meet your needs.

I will tackle the descriptions first.

Aperture
========
This is the width of the telescope.  It is usually approximately the
width of where the light enters the telescope.  The larger the
aperture the brighter the picture will be as more light is captured by
the telescope.  Buying more aperture means a better picture and in
general you should always by the largest you can afford.

Mount
=====
This is the part of the tripod that holds the telescope.  As you are
essentially only interested in viewing terrestrial objects this need
not be an issue for you.

Eyepiece
========
Unlike standard binoculars, a telescope requires that you place a lens
near to where you look into a telescope (on standard binoculars these
lenses are fixed and cannot be removed).  It is the eyepiece that
determines how magnified the image is.

The smaller the size in mm (millimeters) the more magnified the image
will be on a given telescope.

The size of the eyepiece that is given in inches is usually the
diameter of the whole eyepiece and not the lens (usual sizes here are
0.96" (outdated and now rarely used), 1.5" and 2").

As the lens size (in mm) decreases the field of view also decreases. 
The field of view is the amount you can see through the eyepiece. 
More instance a wide field of view would allow the user to see the
field an intruder is standing in, whilst a small field of view might
only allow you to see his body (and not his surroundings).

When choosing an eyepiece you need to weigh up how magnified you want
the image and how much you wish to see through the eyepiece.  It is
usual to have a number of eyepieces to allow you to scan the area you
wish to view and to change the eyepiece when you require more
magnification.

Focal length
============
The focal length is used to help determine what your magnification
will be.  To determine the magnification, simply divide the focal
length (in mm) by the size of your eyepiece (in mm).  If you are
looking through the atmosphere (at stars for instance) there are
limits to the usefulness of this measure but this is not so much of a
problem in your situation.  In summary the larger the focal length the
more magnified the image will be for a fixed eyepiece, buy as large as
you can!

Focal Ratio
===========
Focal ratio, or f number, is the focal length of a lens divided by its
diameter.  In general, the slower the telescope (the larger the f
number), the more forgiving it is of defects.  Consideration of this
should not be too much of a factor in your situation.

I believe these are the major terms you will come across but should
you need to know any further terms please ask for further assistance.

There is also a good beginner's guide here:
http://www.r-clarke.org.uk/telescope_glossary.htm

In summary, buy as wide a telescope as possible with as large a focal
length as possible and a number of different eyepieces allowing you a
range of magnifications.

The type of telescope you can buy is also optional.  The type of
telescope I would recommend to you is a ?catadioptric? one.  In basic
terms it uses some clever optical tricks to make the instrument more
compact and easier to move around without compromising in the
magnification on offer.  There are a number of different sizes of
these available ranging vastly in price.

I would recommend the following manufacturers as ones to look out for
for good priced telescopes of this type:

Meade: http://www.meade.com
Celestron: http://www.celestron.com

Personally, I own an 8" Meade LX200 telescope which I have found more
than sufficient for my needs.  It is rather large and bulky to move
around but it can be done reasonably easily without too much fuss.

The focal length of this telescope is 2000mm.  Therefore with some
standard size eyepieces I can achieve these magnifications:

 4mm eyepiece - 500x (but difficult to use!)
15mm eyepiece - 133x
26mm eyepiece - 76x
40mm eyepiece - 50x

Hopefully this answer will begin to meet your needs.  I am sure you
will have further questions so please do not heistate to ask for
clarification and I will do my best to respond swiftly.

Guides to choosing a telescope:
http://www.meade.com/support/choosing.html
http://www.celestron.com/education/tel4ast.htm
http://www.celestron.com/education/binbasic.htm
http://www.actonastro.com/telescope.htm
http://www.bestbuy.com/site/olspage.jsp?guideID=1043363093646&categoryRep=cat04000&type=page&cmp=&id=cat12077
http://www.sipe.com/starcruiser/observatory/html/fg_firstscope.html

Useful starting place to discover places to buy telescopes:
http://www.astromart.com/aboutus/sponsors.asp

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Request for Answer Clarification by jennyinjamaica-ga on 19 Jan 2006 05:25 PST

Thank you for the explanations - it certainly helps. I didn't know
that a regular telescope (one that you use to view the sky at night)
could be used to view things on land, and during the day. Is that
right? Would a regular telescope be useful both during the day and at
night, or should I be looking for something specifically made for
terrestrial viewing?

Also, I guessed that something that would allow you to see the moon,
for example, would not do well with viewing something only 600 feet to
a mile away. Is that wrong?

Considering what we want to use the scope for, what do you think is a
reasonable price range? I'm rather overwhelmed by all of the choices
and information!

---

Clarification of Answer by palitoy-ga on 19 Jan 2006 06:01 PST

You can use any telescope to look at items on the earth or on the
moon, all a telescope does is to magnify the light it receives.  I
regularly use my smaller ETX-90 telescope to view the moon and also
use it to watch birds less than 30 feet away on bird feeders in my
garden.

One thing I did forget to mention is you will need to buy an adaptor
that will make the image appear the right way up, otherwise everything
will be upside-down in your telescope!  This adaptor is called a
diagonal, the size you get will depend on the eyepieces you wish to
use and the size of your telescope.

I would highly recommend if you can to go and "test drive" a few
telescopes at a local store.  If you do not have a specialised
astronomy store nearby camera stores also often sell telescopes.  Or,
if you have a local astronomy club or observatory they would probably
be willing for you to try a few different telescopes out whilst
someone assists you.

If you were looking for a well priced small telescope which is easy to
use I would certainly recommend a Meade ETX-90 or for a little more
money ETX-125.  I have had a small ETX-90 for several years and found
it to be excellent value for money as it offers excellent crisp views
and is very portable.

Both of these telescopes are very common and have favourable reviews. 
As you are requiring yours mostly for terrestrial viewing you should
try to look for the "spotting scope" versions (they have additional
versions that have computerised controls for looking into the heavens
but this is not really needed for you and only adds to the overall
cost).

The ETX-90/125 spotting scopes come with the diagonal (as mentioned
above) so the image is the right way up.

The difference between the two models, other than price, is mainly the
size of the telescope and the magnification it can reach.  The ETX-90
has a 90mm diameter lens whilst the ETX-125 has a 1250mm lens. 
Remember the larger the diameter the more light it can receive and
therefore darker objects will be easier to see at night.

The ETX-90 also has a smaller focal length (1250mm) compared to the
ETX-125 (1900mm).  This means that with the same eyepieces the ETX-125
will have stronger magnification (as well as the image being
brighter).

Both telescopes come with 3 eyepieces as standard giving the following
magnifications:

       ETX-90    ETX-125
26mm    48x        73x
15mm    83x       127x 
9.7mm  129x       196x

Compare these magnifications with your binoculars to see how much more
powerful they are!

Full details on both of these telescopes can be seen here:
http://www.meade.com/catalog/etx/etx_spotting.html

For prices of these telescopes I would recommend you to try and buy a
copy of Sky And Telescope magazine as this usually has all the
different store's deals in its advertisements.  As a quick guide an
ETX-90 can be purchased for around $400 whilst the larger ETX-125 can
be bought for around $700.

I hope this additional information is helpful but should you still
require further assistance please ask again.

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Request for Answer Clarification by jennyinjamaica-ga on 20 Jan 2006 18:09 PST

Great - I have a much better idea now. One more question - husband
announced to me today that he wants to be able to look with both eyes.
I sighed with exasperation and explained that we were looking for a
telescope - not binoculars! Is there some kind of adaptor that allows
you to look through with both eyes?

---

Clarification of Answer by palitoy-ga on 21 Jan 2006 01:50 PST

Yes, there are adaptors that can allow you to look with both eyes. 
These are quite expensive and require you to have double the number of
eyepieces (as you require two of each eyepiece).  On smaller
telescopes these can be quite difficult to use due to their size and
weight.

The adaptor you require would be called a "binocular viewer".  An
example is shown on this page:
http://www.celestron.com/prod_pgs/accessories/optical_accessories.htm

It essentially fits on the telescope where your single eyepiece used
to go and it splits the light so that it can go to both of your eyes.

Telescopes meant for night viewing often show an "inverted" (upside
down) image, which isn't convenient for daytime use.  I think what you
need is called a "spotting scope".  These almost always have the image
right-side up, are typically 12 to 18 inches long, and mounted on a
tripod.  Sometimes they have "zoom" capabilities (the ability to
change the magnification).  There are pros and cons about this
capability.

You can check with Orion Telescope Center, Meade Instruments, and
Celestron Telescopes, all of whom should have web sites.  I used to
work at Orion Telescope Center (sheesh, over 25 years ago, now!) and
have a good opinion of them.  (I've since bought other optical gear
from them.)  You can contact any of these companies and just tell them
you are a beginner.  They'll be glad to explain anything you don't
understand.

J.