A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Astronomy and Astrophysics » Amateur Astronomy
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

sub-amateur has dumb questions



 
 
Thread Tools Display Modes
  #1  
Old August 27th 03, 07:08 AM
paul beard
external usenet poster
 
Posts: n/a
Default sub-amateur has dumb questions

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
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.
  #2  
Old August 27th 03, 07:22 AM
bwhiting
external usenet poster
 
Posts: n/a
Default sub-amateur has dumb questions

All I know Paul, that if the image is getting bigger and blobbier,
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.




paul beard wrote:

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
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.


  #3  
Old August 27th 03, 07:22 AM
bwhiting
external usenet poster
 
Posts: n/a
Default sub-amateur has dumb questions

All I know Paul, that if the image is getting bigger and blobbier,
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.




paul beard wrote:

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
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.


  #4  
Old August 27th 03, 07:25 AM
Starstuffed
external usenet poster
 
Posts: n/a
Default sub-amateur has dumb questions

Paul wrote:

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



  #5  
Old August 27th 03, 07:25 AM
Starstuffed
external usenet poster
 
Posts: n/a
Default sub-amateur has dumb questions

Paul wrote:

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



  #6  
Old August 27th 03, 07:28 AM
Matt Tulini
external usenet poster
 
Posts: n/a
Default sub-amateur has dumb questions

paul beard wrote:

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.

  #7  
Old August 27th 03, 07:28 AM
Matt Tulini
external usenet poster
 
Posts: n/a
Default sub-amateur has dumb questions

paul beard wrote:

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.

  #8  
Old August 27th 03, 08:07 AM
bwhiting
external usenet poster
 
Posts: n/a
Default sub-amateur has dumb questions

Also remember Paul,
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.



paul beard wrote:

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
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.


  #9  
Old August 27th 03, 08:07 AM
bwhiting
external usenet poster
 
Posts: n/a
Default sub-amateur has dumb questions

Also remember Paul,
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.



paul beard wrote:

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
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.


  #10  
Old August 27th 03, 02:27 PM
Davoud
external usenet poster
 
Posts: n/a
Default sub-amateur has dumb questions

paul beard:
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
anything a 6 year old will find interesting...


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
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Dumb SS1 questions Henry Spencer Technology 23 July 9th 04 07:08 PM
sci.space.tech and sci.space.science Frequently Asked Questions (FAQ) s.s.t moderator Technology 0 November 9th 03 12:02 PM
sci.space.tech and sci.space.science Frequently Asked Questions (FAQ) s.s.t moderator Technology 0 November 2nd 03 12:02 PM
sci.space.tech and sci.space.science Frequently Asked Questions (FAQ) s.s.t moderator Technology 0 October 26th 03 12:02 PM
Amateur astronomer locates powerful stellar explosion before thepros (Forwarded) Andrew Yee Astronomy Misc 0 August 12th 03 10:16 PM


All times are GMT +1. The time now is 11:35 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 SpaceBanter.com.
The comments are property of their posters.