Looking for eye peices that will go with my scope

[mikeluvs43 (Mike)]

Looking for advice on eye peices
Hi all I just got my girlfriend a Orion SpaceProbe 130 EQ Reflector Telescope
with 900 mm focal lengh

it came with a 10mm and a 25 mm lens
I also bought a Orion Shorty 2x Barlow Lens, 1.25"
and a moon filter

Saturday was her birthday It gets great shots of the moon
We tried looking at Saturn seeing it was out last night but can't get to close

We see it shinning like a star but what would I need to get a CLOSER look at it?

Or any other planets for that matter

(besides a new telescope)

Any strong lenses that will do me better?

Anyone selling lenses that will go with her scope other then ones that are basically the same as I have please let me know.

or anything you may have for sale that will go with her equipment that will add to seeing great things in the sky let me know



Thanks Mike

[peter brown]

best to write in beginners forum for advice

pb

[rogerco (Roger)]

Sorry but 900mm isn't going to get you very close to saturn, the 10mm plus 2x barlow are probably about as big a magnification you are sensibly going to get given that you will need very good seeing to get better.

Having said that if you want to play with a 5x barlow I have one but please be warned it is almost impossible to use as the image shimmers too much and saturn goes out of view far to quickly.

email me direct - roger_vk2tea@bigpond.com

no idea what its worth probably just the postage.

Roger Cooper

[rogerco (Roger)]

Just been out looking at saturn (only just out of the mirk at 20 degrees above horizon, but thought I would take a look after my comment previous).

Using a 1200mm focal length 200mm bintel dobsonian. 15mm Televue Plossl in a Televue 2.5x powermate.

Very nice look at saturn. Not big, say about 1/6 to 1/10 of FOV but very clear and even with the rings nearly flat they were very clear. You could see them in front of the planet, some indication of striation on the planet and the gap (loops of the "handle") between the inner side of the rings and the planet was clearly visiable. Best I have seen it so far

Tried it with a 8mm Plossl (and the powermate) but it was impossible to point with the dobsonian mount. EQ3 might be a different matter but motor drive would be best.

Roger

[Allan_L (Allan)]

Originally Posted by mikeluvs43

Looking for advice on eye peices
Hi all I just got my girlfriend a Orion SpaceProbe 130 EQ Reflector Telescope
with 900 mm focal lengh
it came with a 10mm and a 25 mm lens
I also bought a Orion Shorty 2x Barlow Lens, 1.25"
and a moon filter
Saturday was her birthday It gets great shots of the moon
We tried looking at Saturn seeing it was out last night but can't get to close
We see it shinning like a star but what would I need to get a CLOSER look at it?
Or any other planets for that matter
(besides a new telescope)
Any strong lenses that will do me better?
Thanks Mike

Hi Mike
Hi Mikes girlfriend

Orion 130, EQ, sounds like a pretty darn good starter scope to me.
with focal length of 900.
That would be an f7 (approx)

General rule is that best you can expect to use is half the f number (IMHO).
So that would be a 3.5mm.
However, that is under good seeing conditions and close to zenith.
(seeing conditions is like bad atmospheric stuff) - like the haze seen looking up a road in the outback!
And closer to zenith (overhead) reduces the amount of bad stuff you gotta look through.
Also, it is important to cool your scope to ambient temperatures to reduce internal convection waves.

The orion shorty is a pretty good barlow too.
As rogerco says, the 10mm with the 2x orion barlow is probably as good as you are going to be able to get. That effectively changes your 10mm into a 5mm.

[Magnification = focal length divided by eypiece size in mm.
So your 900 divided by 10mm = 90 times.
With the barlow 900 / 5 = 180 times.]

If you really want to buy something, I suggest you buy a 7mm. Then with your barlow, that gives you the 3.5 which is about as good as it will get. But only on good nights and conditions.

[900 / 7 = 129 times but with the barlow
900 / 3.5 = 257 times magnification]

[and that general rule is that the best magnification you can hope for under good seeing conditions is twice the aperture in mm. So 130 x 2 = 260.]

But as i said, atmospheric conditions count for heaps, so just because you did not get great Saturn views with your equipment last time, does not mean that is what you are saddled with for all time.

Keep trying with what you have.

You should get a pretty good image (maybe a little small) but clearly in focus. As described, you should be seeing more than just a star with a bulge.

One last thing, you own eyes.
They can take an hour to get dark adjusted.
What you see then will be an improvement on what you see when you first set up the scope.

Good luck. Hope this helps a bit.
Let us know how you go.

clear skies !!
allan