sub-amateur has dumb questions
paul beard
as far as I can tell, it's complete. With the Mars conjunction
underway, I have been trying to work out how I can actually see
anything a 6 year old will find interesting.
I can see Mars with the naked eye, get it centered in the viewfinder
and in the telescope eye piece: I see a brilliant orange thing, bright
but tiny. So far so good. I crank the eyepiece end of things out and
watch the orange thing get bigger but increasingly blurry until it
fills the eyepiece completely.
Now what? How can I focus the telescope to see any actual detail? Or
am I doomed to see nothing more than the Neanderthals saw the last
time Mars was this close?
It seems to me there should be some more granular controls somewhere,
but other than the knobs that lock and unlock the telescope barrel
from moving, I don't see anything.
here's a picture thay may help, if you need more detail:
http://buy.overstock.com/images/products/L929792.jpg
Thanks for any help.
bwhiting
you're cranking the focus the wrong way....to properly focus a scope, it
is better to pick a bright star first, center it, and move the
focuser until the star reaches its minimum size--should be an extremely
small pin-point, or as close as you can get to it....(atmospherics
plays a role here, in addition to 'cool down' time for the scope.
A scope of that size you should allow about 30-60 minutes cool-down time
outside.)
NOW you are focused on infinity. Now move
the scope back to Mars. Same holds true for focusing on Mars, if
you must...the minimum size you obtain will be the "in focus"
position, whether Mars 'looks good' to you, or not.
Clear Skies,
Tom W.
Starstuffed
>>I can see Mars with the naked eye, get it centered in the viewfinder
and in the telescope eye piece: I see a brilliant orange thing, bright
but tiny. So far so good. I crank the eyepiece end of things out and
watch the orange thing get bigger but increasingly blurry until it
fills the eyepiece completely.<<<
When Mars appears as small as you can get it through the telescope then that
would be when it is properly focused. If the image is too small for you at
that point, then you need a more powerful eyepiece. Your eyepieces have
numbers on them. Numbers like: 25mm, 18mm, 12mm, 6mm, and etc. The
smaller the number, the more powerful the eyepiece. On the tube of that
scope somewhere you should see its focal length. . .Something like 480mm,
700mm, 910mm. Divide the number on the eyepiece into the focal length of
the telescope to derive the power of the scope using that eyepiece. Good
luck.
Martin
Matt Tulini
<snip>
> I can see Mars with the naked eye, get it centered in the viewfinder
> and in the telescope eye piece: I see a brilliant orange thing, bright
> but tiny. So far so good. I crank the eyepiece end of things out and
> watch the orange thing get bigger but increasingly blurry until it
> fills the eyepiece completely.
Most likely it was in focus when it appeared "tiny". I can tell you
that if it fills the entire eyepiece, it is most certainly out of focus.
;-) In focus, it'll probably look the size of a dime from 6 feet
away. (not a scientific measure, just the way I perceive it to look)
> Now what? How can I focus the telescope to see any actual detail? Or
> am I doomed to see nothing more than the Neanderthals saw the last
> time Mars was this close?
You should probably be able to see a fair amount of detail, but it's not
going to look like Hubble. Take some time, focus the image, and stare
at it for a while. You may be able to see the ice cap and some dark
areas on the surface.
> It seems to me there should be some more granular controls somewhere,
> but other than the knobs that lock and unlock the telescope barrel
> from moving, I don't see anything.
Some higher-end telescopes have finer focusing controls. What you've
got is probably adequate though, just focus carefully.
HTH
-Matt
--
Remove 'TINLC' to reply.
bwhiting
Mars is only 25 arc-seconds in diameter at its closest.....and
within 10% of that value until about the end of September.
But 25 arc-seconds is not very large....a pretty double star
up in Cygnus, Albireo (or Beta Cygni, at the end of the "northern
cross" asterism) is split by 34 arc-seconds! Mars' diameter
could easily fit between those two components! We aren't talking
a huge ball here, like the moon in a scope. Mars is only 4200 miles
in diameter, and out there about 34.6 million miles...that's only
about twice the diameter of our own moon, and only half the Earth's
diameter.....only Mercury and Pluto (if you consider Pluto a.....UGH!
planet) are smaller than Mars. We're not talking a large gas giant
here, like Jupiter at 88,000 miles in diameter. So you have to keep
that in mind.....PLUS, it doesn't look like you are using a 6 or 8 or 10
inch glass there, are you? More like 2 or 3 inches of glass....
so with a very small scope, don't expect to see an "orange" filling
half the field of view (when in proper focus)....it ain't gonna happen
with a 2 or 3 inch scope, at only 25 arc-seconds in diameter.
Sorry. {Remember, our moon probably fills the entire field of view in
your scope, but that's 1/2 degree across, or 1800 arc-seconds!)
Mars is only 1.4% (25/1800) the angular size (image size) of our moon
in that same eyepiece, at its best!}
Clear Skies,
Tom W.
guid0
up to the plate and batted:
>here's a picture thay may help, if you need more detail:
>http://buy.overstock.com/images/products/L929792.jpg
>
>Thanks for any help.
The item I really like is this reflector pictured with the finderscope
pointing the wrong way
http://www.overstock.com/cgi-bin/d2.cgi?PAGE=PROFRAME&PROD_ID=305827
Now you can have your chest centered with the back of the mirror at
all times.
G../0
Davoud
> Someone gave my son (and by extension, me) a Meade 155W telescope, and
> as far as I can tell, it's complete. With the Mars conjunction
> underway, I have been trying to work out how I can actually see
Others have answered your questions. I would only note that you
shouldn't belittle yourself because:
a) You are an amateur like all other amateur astronomers.
b) Your questions are not dumb.
Davoud
--
usenet *at* davidillig dawt com
Al Arduengo
I found the item directly below it in the right column interesting. It
appears to be some new reflector in a refractor package. We should call
it a "reflactor"!
-Al
Jon Isaacs
>http://buy.overstock.com/images/products/L929792.jpg
>
A bit of a Heads Up.
The scope is mounted backwards in the photo. The way it is mounted in the
photo it could only be used to 20 degrees elevation. I am quite sure the OP
recognized this when setting up the scope.
jon
lal_truckee
> I have been trying to work out how I can actually see
> anything a 6 year old will find interesting.
See other replies, particularly about magnification and focus:
I just wanted to point out that interpreting what he sees on Mars with
this scope may be beyond and therefore uninteresting to a 6 year old -
start with the moon to excite him, go from there. Then by the time Mars
rolls around again in a couple of years he should be primed to check it out.
paul beard
him any detail on Mars is out of the question, so perhaps the moon is
a better choice.
it really doesn't appear any larger in the viewfinder than to the
naked eye, sadly. Now that I have a better idea what I'm doing, I'll
take a little more time and see what I can see.
Thanks again.
Tim Longwell
more on that.
Might I suggest when looking at the Moon, Do so when it is a partial phase
and not as much when Full.
Then look along the terminator, the line where the dark and light meet and
you will see more than you will when looking at a full moon.
Nice thing about doing that is you can also do that during daylight.
Makes it easier to get that 6 year old up for school the next morning 8*)
--
Clear Skies!
========
Tim Longwell
Black River Astronomical Society
http://junior.apk.net/~arstar50/BlackRiver.index.html
Elyria, Ohio
=========
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