telescope question

Hi all a newbie here, so i got a telescope for xmas just a cheapy one so my
question is ive had a really good look at the moon and it looks cool but id
like to take alook at some other planets and ive seen saturn next to the
moon id really love to seen the rings if possible but im not sure which
lens's id need to use, heres what came with the scope.

The scope says its focal length is 700m its got a 20mm,12.5mm and a 4mm eye
piece and its also got 2 eye piece extensions of 1.5X and 3X Barlow lens.
Must say its the best present ive had in a long time, and cheers for any
help

other planets and ive seen saturn next to the moon id really love to seen
the rings if possible

Use your 20mm to centre it and then with the 12.5 you should be able to make
out the rings, the 4mm then they should look really cool.

--
Damian Burrin
UKRA 1159 Level 2 RSO
EARS 1115
http://www.ukrocketry.com
http://www.larf-rocketry.co.uk

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"Jonathan Horseman" wrote in message
...
Hi all a newbie here, so i got a telescope for xmas just a cheapy one so
my question is ive had a really good look at the moon and it looks cool
but id like to take alook at some other planets and ive seen saturn next
to the moon id really love to seen the rings if possible but im not sure
which lens's id need to use, heres what came with the scope.

The scope says its focal length is 700m its got a 20mm,12.5mm and a 4mm
eye piece and its also got 2 eye piece extensions of 1.5X and 3X Barlow
lens. Must say its the best present ive had in a long time, and cheers for
any help

On Tue, 28 Dec 2004 20:23:34 +0000, Jonathan Horseman wrote:
ive seen saturn next to the
moon id really love to seen the rings if possible but im not sure which
lens's id need to use, heres what came with the scope.

The scope says its focal length is 700m its got a 20mm,12.5mm and a 4mm eye
piece and its also got 2 eye piece extensions of 1.5X and 3X Barlow lens.

I've just got in after having 5 minutes without cloud.I've got a similar
scope as yours - 700mm, and using the 10mm lens, Saturn and its rings were
clearly visible with the 10mm lens.I then went to try it with the 2x
barlow lens but cloud intervened again.
I thought at first the scope was not focused - the planet looked oval/out
of focus, but once the scope had stopped shaking, it was clearly visible
as rings separate from the planet - the first time I'd seen them ,so I'm
thrilled!
I think the trouble with cheap scopes is the poor quality lenses.With the
standard 25mm lens, everything looks sharp, with the 10mm the
magnification is getting bigger, so aberations in the lens are more
apparent.This is most noticable when viewing the moon with the 10mm lens
combined with the 2x Barlow lens.With both the 25mm and 10mm on their own,
the image is quite good, but once the barlow is added, the viewed image
deteriorates badly - so badly that I'm not sure if it would be any good
for planet viewing.
I think you wont be able to use the 3x barlow for much, but you never
know, yours may be better quality than mine, so it could be fine.
What do you use for finding planets/stars?
I've been using a program called 'Stellarium', which is dead easy to use.
See here for details:
http://stellarium.free.fr/index.html
You can have a look around the sky, see something, then go in and see its
name.Ideal for idiots like me who only know the moon by sight!
Alan.

--
To reply by e-mail, change the ' + ' to 'plus'.
http://www.dvatc.co.uk - Off-road cycling in the North Midlands.

I've been using a program called 'Stellarium', which is dead easy to ?use.
See here for details:

Pocket Stars for thr pocket pc rocks and it's sister version pocket stars
PC.

www.nomadelectronics.com

Jay who writes it is a very nice guy too.

Best thing about this software is that it's extremly cheap to register and
the demo is fully functional. Check it out.

Damian

--
Damian Burrin
UKRA 1159 Level 2 RSO
EARS 1115
http://www.ukrocketry.com
http://www.larf-rocketry.co.uk

email
email
email
"A.Lee" wrote in message
...
On Tue, 28 Dec 2004 20:23:34 +0000, Jonathan Horseman wrote:
ive seen saturn next to the
moon id really love to seen the rings if possible but im not sure which
lens's id need to use, heres what came with the scope.

The scope says its focal length is 700m its got a 20mm,12.5mm and a 4mm
eye
piece and its also got 2 eye piece extensions of 1.5X and 3X Barlow
lens.

I've just got in after having 5 minutes without cloud.I've got a similar
scope as yours - 700mm, and using the 10mm lens, Saturn and its rings were
clearly visible with the 10mm lens.I then went to try it with the 2x
barlow lens but cloud intervened again.
I thought at first the scope was not focused - the planet looked oval/out
of focus, but once the scope had stopped shaking, it was clearly visible
as rings separate from the planet - the first time I'd seen them ,so I'm
thrilled!
I think the trouble with cheap scopes is the poor quality lenses.With the
standard 25mm lens, everything looks sharp, with the 10mm the
magnification is getting bigger, so aberations in the lens are more
apparent.This is most noticable when viewing the moon with the 10mm lens
combined with the 2x Barlow lens.With both the 25mm and 10mm on their own,
the image is quite good, but once the barlow is added, the viewed image
deteriorates badly - so badly that I'm not sure if it would be any good
for planet viewing.
I think you wont be able to use the 3x barlow for much, but you never
know, yours may be better quality than mine, so it could be fine.
What do you use for finding planets/stars?
I've been using a program called 'Stellarium', which is dead easy to use.
See here for details:
http://stellarium.free.fr/index.html
You can have a look around the sky, see something, then go in and see its
name.Ideal for idiots like me who only know the moon by sight!
Alan.

--
To reply by e-mail, change the ' + ' to 'plus'.
http://www.dvatc.co.uk - Off-road cycling in the North Midlands.

"A.Lee" wrote in message
...
On Tue, 28 Dec 2004 20:23:34 +0000, Jonathan Horseman wrote:
ive seen saturn next to the
moon id really love to seen the rings if possible but im not sure which
lens's id need to use, heres what came with the scope.

The scope says its focal length is 700m its got a 20mm,12.5mm and a 4mm
eye
piece and its also got 2 eye piece extensions of 1.5X and 3X Barlow
lens.

I've just got in after having 5 minutes without cloud.I've got a similar
scope as yours - 700mm, and using the 10mm lens, Saturn and its rings were
clearly visible with the 10mm lens.I then went to try it with the 2x
barlow lens but cloud intervened again.
I thought at first the scope was not focused - the planet looked oval/out
of focus, but once the scope had stopped shaking, it was clearly visible
as rings separate from the planet - the first time I'd seen them ,so I'm
thrilled!
I think the trouble with cheap scopes is the poor quality lenses.With the
standard 25mm lens, everything looks sharp, with the 10mm the
magnification is getting bigger, so aberations in the lens are more
apparent.This is most noticable when viewing the moon with the 10mm lens
combined with the 2x Barlow lens.With both the 25mm and 10mm on their own,
the image is quite good, but once the barlow is added, the viewed image
deteriorates badly - so badly that I'm not sure if it would be any good
for planet viewing.
I think you wont be able to use the 3x barlow for much, but you never
know, yours may be better quality than mine, so it could be fine.
What do you use for finding planets/stars?
I've been using a program called 'Stellarium', which is dead easy to use.
See here for details:
http://stellarium.free.fr/index.html
You can have a look around the sky, see something, then go in and see its
name.Ideal for idiots like me who only know the moon by sight!
Alan.

--
To reply by e-mail, change the ' + ' to 'plus'.
http://www.dvatc.co.uk - Off-road cycling in the North Midlands.


Ive just been using Starry night Enthusiast 4.5 to get a rough idea on where
the planets are, im gonna take a look at the web site you suggested might be
more helpful for me. thanx for the replies

Jonathan Horseman wrote:

The scope says its focal length is 700m its got a 20mm,12.5mm and a 4mm eye
piece and its also got 2 eye piece extensions of 1.5X and 3X Barlow lens.
Must say its the best present ive had in a long time, and cheers for any
help

You can get the actual magnification by dividing the focal length of the
telescope by the focal length of the eyepieces.

Hence: 700/20 = x35
700/12.5 = x56
700/4 = x175

In addition to that the Barlow lenses will effectively multiply the
magnification by their stated amount, so for example the 20mm e/p with
the 1.5x Barlow will give you (700/20)*1.5 = x52.5.

However, there is an upper limit to the magnification you can use. It's
limited by seeing (how steady the air is), by the quality of the various
optical components and by a few other things. The limit _tends_ to work
out at about 50x per inch of aperture of the telescope. So, if you have
an 80mm telescope (3" ish) then you probably don't want to go beyond
50*3, ie 150x.

The best way, however, is just to experiment and see what works best
because there are always exceptions and they vary from person to person,
and telescope to telescope.

Most of all - have fun!

Jim
--
Find me at http://www.ursaminorbeta.co.uk AIM/iChatAV: JCAndrew2
"We deal in the moral equivalent of black holes, where the normal
laws of right and wrong break down; beyond those metaphysical
event horizons there exist ... special circumstances" - Use Of Weapons

"A.Lee" wrote in message
...
On Tue, 28 Dec 2004 20:23:34 +0000, Jonathan Horseman wrote:
ive seen saturn next to the
moon id really love to seen the rings if possible but im not sure which
lens's id need to use, heres what came with the scope.

The scope says its focal length is 700m its got a 20mm,12.5mm and a 4mm
eye
piece and its also got 2 eye piece extensions of 1.5X and 3X Barlow
lens.

I've just got in after having 5 minutes without cloud.I've got a similar
scope as yours - 700mm, and using the 10mm lens, Saturn and its rings were
clearly visible with the 10mm lens.I then went to try it with the 2x
barlow lens but cloud intervened again.
I thought at first the scope was not focused - the planet looked oval/out
of focus, but once the scope had stopped shaking, it was clearly visible
as rings separate from the planet - the first time I'd seen them ,so I'm
thrilled!
I think the trouble with cheap scopes is the poor quality lenses.With the
standard 25mm lens, everything looks sharp, with the 10mm the
magnification is getting bigger, so aberations in the lens are more
apparent.This is most noticable when viewing the moon with the 10mm lens
combined with the 2x Barlow lens.With both the 25mm and 10mm on their own,
the image is quite good, but once the barlow is added, the viewed image
deteriorates badly - so badly that I'm not sure if it would be any good
for planet viewing.
I think you wont be able to use the 3x barlow for much, but you never
know, yours may be better quality than mine, so it could be fine.
What do you use for finding planets/stars?
I've been using a program called 'Stellarium', which is dead easy to use.
See here for details:
http://stellarium.free.fr/index.html
You can have a look around the sky, see something, then go in and see its
name.Ideal for idiots like me who only know the moon by sight!
Alan.

--
To reply by e-mail, change the ' + ' to 'plus'.
http://www.dvatc.co.uk - Off-road cycling in the North Midlands.


I like the freeware MicroSky from http://www.upto.org/microsky/

It's a freeware planetarium for java enabled mobile/cell phones.

Martin.