Barlow"s

[Clarry (Clayton)]

Hello again people. As some of you will know, I am the proud owner of my first telescope, an 8" Dobsonian. It came with 2 eyepieces, 9mm and 25mm 1.25" Plossl's. Now that I've been reading the threads here, I see a lot of comments on Barlow eyepieces. My understanding is that they will give me double the magnification of normal one's. Is that correct or am I mistaken? If I was to purchase 1 or 2 Barlow's, which sizes would you recommend taking my existing eyepieces in to consideration? I also have a green filter for the moon, is there another filter that I really should have to make my viewing a more fulfilling experience?

[erick (Eric)]

Hi Clayton

A barlow lens is placed between your eyepiece and the focusser. It has various effects, but mainly it is the magnifying one that is of most significance. They seem to come in 2x, 3x and 5x. They also come in 2" or 1.25" diameters.

Do a bit of searching for "barlow" on this forum and you'll find recommendations.

Filters! Again, search the threads and you'll find some lengthy threads on filters with lots of references to useful sites. It really depends on what you want to be observing. It seems to me that there are about two or three types of filters that have various benefits for observers. They can be quite expensive! And you have to decide whether you need 2" or 1.25" or both.

[dannat (Daniel)]

clayton, for visual most use 2x, which would give the ep's you have a range of 12.5mm(with the 25) & 4.5(9mm). this would then give you a good spread. do you have a 2" focuser or 1.25". how much were you thinkng of spending?

[Clarry (Clayton)]

Thanks guys, I have a 1.25" focuser. Money is tight so the less I spend the better. Am I right in thinking they are about $50.00 each?

[erick (Eric)]

Janoskiss always recommends the following. He's what he said earlier:-

"Best barlow for high powers IME is the fully baffled Orion Deluxe 1.25". Got mine for $99 from Sirius Optics in QLD. An absolute bargain."

Not sure of current price. OK, just looked it up:-

http://www.sirius-optics.com.au/barlowe_pieces.htm

$120.

[astroturf (Bryan)]

It sounds like you're not too happy with the "green" filter
I don't like mine & it has been living in the desk drawer since about 2 weeks after I bought it
If you like checking out the moon I would recommend a variable polarising filter,they are adjustable depending on the glare & they cost about $45 & are also good for looking at planets as well

Bryan

[erick (Eric)]

Clayton

If you are just talking about improved ways to reduce the brightness of the Moon (and Venus and perhaps Jupiter) then I agree with the crossed polarising filter approach:-

http://www.iceinspace.com.au/forum/s...ad.php?t=42428

http://www.iceinspace.com.au/forum/s...ad.php?t=27821

[Clarry (Clayton)]

Had a good read of the filter thread erick, thanks for that. I'll look into the Orion Deluxe Barlow. Thanks for the advice people.