Barlow Lenses

I have a 3x Barlow lenses that can with my scope.
I never use it because a) it severely dims the objects I'm looking at
(in particular the moon) and b) it has somehow gotten very dirty dusty.
It looks like a lint collector has been keeping it in his pocket.

Since I can't seem to get it clean and since I never enjoyed it much anyway
I'm thinking about purchasing a 2x Barlow.

My question is, what should I pay and what should I get?
Is it the quality of my current lens that is putting me off (never mind the
dust)?
It looks like a cheap plastic thing that goes into a kids toy.

I don't want to throw good money at a low budget scope, but I do want to
maximize what I can do within a very tight budget (can you say b-r-o-k-e)

My scope is a Bushnell....I think this is a 1.25 lens.
675x4.5" Reflector
Focal length (mm)
900

EYEPIECES I own are...
4mm, 12mm, 20mm

This tiny purchase is also an excuse to visit my local telescope store for
the
first time. I am dying to go and look and drool, but I would hate to without
buying anything. Especially since I KNOW that once I go in I'll have a
zillion
questions.

thanks,
jojo

On 2003-09-18 23:18 +0900, jojo wrote:

Since I can't seem to get it clean and since I never enjoyed it much anyway
I'm thinking about purchasing a 2x Barlow.

My question is, what should I pay and what should I get?

A Celestron Ultima 2x barlow would be a decent investment if your
scope can take 1 1/4" EPs/accessories. It's not outrageously
expensive and is decent enough that you'd want to hang onto it
with pretty much any scope you use in the future.

I don't want to throw good money at a low budget scope, but I do want to
maximize what I can do within a very tight budget (can you say b-r-o-k-e)

I hear ya on broke, man.

trane
--
//------------------------------------------------------------
// Trane Francks Tokyo, Japan
// Practice random kindness and senseless acts of beauty.
// http://mp3.com/trane_francks/

On Thu, 18 Sep 2003 14:18:48 GMT, "jojo"
wrote:

I'm thinking about purchasing a 2x Barlow.

My question is, what should I pay and what should I get?

You absolutely cannot go wrong with Orion's Shorty Plus. At around
$60, it seems to be the equal of any other 2X barlow from the
"premium" makers, and superior to the rest.

Wayne Hoffman
33° 49" 17' N 117° 56" 41' W
"Don't Look Down"

http://home.pacbell.net/w6wlr/

On Thu, 18 Sep 2003 14:18:48 GMT, "jojo" ...reflected:

I have a 3x Barlow lenses that can with my scope.
I never use it because a) it severely dims the objects I'm looking at
(in particular the moon) and b) it has somehow gotten very dirty dusty.
It looks like a lint collector has been keeping it in his pocket.

Since I can't seem to get it clean and since I never enjoyed it much anyway
I'm thinking about purchasing a 2x Barlow.

My question is, what should I pay and what should I get?

The ideal would be an Orion barlow, and for less than $50...

http://www.telescope.com/jump.jsp?it...GORY&itemID=25

Many seem to prefer the "Shorty", and for only $40; but then their
standard barlow, for $5 more, is made in Japan. Either one would
give good service.

Is it the quality of my current lens that is putting me off (never mind the
dust)?
It looks like a cheap plastic thing that goes into a kids toy.

I don't want to throw good money at a low budget scope, but I do want to
maximize what I can do within a very tight budget (can you say b-r-o-k-e)

Rather, buy decent accessories, one at a time, and later, when
you're able, upgrade to another scope, and then you'll already have the
finer accessories that you had bought for this one.

For instance, here...

http://www.handsonoptics.com/astrono...to_series.html

....you will find inexpensive yet very popular eyepieces. I understand that
they are "hot sellers", and not only due to the low prices.

My scope is a Bushnell....I think this is a 1.25 lens.
675x4.5" Reflector

The 675x magnification indication is grossly exaggerated, and solely
designed to "snooker" the public. Realistically, you may only expect
100x to 150x, and at best. Therefore, you need to select your shortest
focal length eyepiece according to the focal length...

Focal length (mm)
900

...thus the shortest you should buy, without a barlow, would be a
6mm, however that is pushing it a bit. If you use a good-quality barlow,
then a 12mm will do nicely. In any case, buy nothing shorter than a 6mm,
with a 7mm actually being the shortest to consider which will give a
magnification of 129x, and a most happy compromise.

EYEPIECES I own are...
4mm, 12mm, 20mm

Did these come with telescope? If so, then the 12mm and 20mm
are perhaps serviceable, but I made a dustcover for the focusser/star
diagonal out of my 4mm by placing a wood screw through the eyelens.

This tiny purchase is also an excuse to visit my local telescope store for
the
first time. I am dying to go and look and drool, but I would hate to without
buying anything. Especially since I KNOW that once I go in I'll have a
zillion
questions.

You might find that that shop offers a layaway(ah, I remember them
well, but not for buying telescopes). That would give you a good excuse
to go in and...browse...

nasally "May I help you, sir?"

"No thanks. I'm only...browsing."

See how easy? Then, after enduring the salesman's cold, hard stare for
a few minutes, you ask...

"Do you have a...gulp...layaway?"

....and the salesman replies...

"Why, yes...we do."

Then you reply...

"Uh, um, okay. You can stop hovering over me like a vulture now."

8^)

Alan

I've also been looking into Barlows, and would like to add a couple
questions.

Why would one want to go with a short or normal lenght one?

Is it worth it to go for an apo style?

Why does a 2x barlow work as a 3x when placed before a star diagonal?

Mark

WayneH wrote:
On Thu, 18 Sep 2003 14:18:48 GMT, "jojo"
wrote:


I'm thinking about purchasing a 2x Barlow.

My question is, what should I pay and what should I get?


You absolutely cannot go wrong with Orion's Shorty Plus. At around
$60, it seems to be the equal of any other 2X barlow from the
"premium" makers, and superior to the rest.

Wayne Hoffman
33° 49" 17' N 117° 56" 41' W
"Don't Look Down"

http://home.pacbell.net/w6wlr/

"Mark De Smet" wrote in message
...

....[snip]...

Is it worth it to go for an apo style?

Why does a 2x barlow work as a 3x when placed before a star diagonal?

Mark
....[snip]...

Read the explanation here
http://www.astunit.com/tutorials/barlow.htm#%5B2%5D

Bob

Why would one want to go with a short or normal lenght one?

Short ones may be more desirable for scopes that have a star diagonal, due to
there compact size. Folks sometimes have more than one type of scope over the
years, so a shorty one may be a one size fits all.

Short barlows can extend the eye relief on your eps. This can make eye
placement difficult on low power ep's. On the other hand, the purpose of
barlows are to provide higher magnification. Extending eye relief on short
focal length eye pieces is a good thing!

I have noticed that Televue is not making shorty barlows. And the Powermates
are a little longer still. Hmmm.....





john

Well, I had decided to get an Orion shorty 2X Barlow, but
my local shop does not have them right now.
He did recommend an Omcom (made my Anteries).
He claims the quality is just as good as the Orion for
4 bucks less.

Any thoughts?

Thanks,
jojo

On Fri, 19 Sep 2003 18:46:59 GMT, "jojo"
wrote:

Well, I had decided to get an Orion shorty 2X Barlow, but
my local shop does not have them right now.
He did recommend an Omcom (made my Anteries).
He claims the quality is just as good as the Orion for
4 bucks less.

Any thoughts?

Yes. Don't get the plain-vanilla "shorty." BTDT, you'll be
disappointed - go for the "Shorty-Plus," which is far superior.

Wayne Hoffman
33° 49" 17' N 117° 56" 41' W
"Don't Look Down"

http://home.pacbell.net/w6wlr/

"WayneH" wrote in message
...
On Fri, 19 Sep 2003 18:46:59 GMT, "jojo"
wrote:

Well, I had decided to get an Orion shorty 2X Barlow, but
my local shop does not have them right now.
He did recommend an Omcom (made my Anteries).
He claims the quality is just as good as the Orion for
4 bucks less.

Any thoughts?

Yes. Don't get the plain-vanilla "shorty." BTDT, you'll be
disappointed - go for the "Shorty-Plus," which is far superior.

Wayne Hoffman
33° 49" 17' N 117° 56" 41' W
"Don't Look Down"

http://home.pacbell.net/w6wlr/


what is a "shorty plus"???

jojo