Barlow for an F5 scope?

[Dom1961]

Might be a silly question but, ive heard that some scopes need barlows to accompany the eyepieces due to their scope focal length? My scope is 650mm and i am thinking of getting  Revelation 9mm, 20mm and 32mm eyepieces, will I need a barlow? Any help would be appreciated!

[triton1]

The revelation Barlow from Telescope house seems to get good reviews on here.x2 about £32 I think.

[Dave In Vermont]

Dom:

You don't "need" a Barlow, but you may want one for certain pursuits - such as planetary viewing. And then if you wish to see better details in such as Saturn's rings or Jupiter's belts. As you didn't post what telescope you have, other than it's being an F5 with a F.L. of 650mm, I am able to deduce it has a primary mirror of 130mm diameter. So a 9mm eyepiece will give you 72.2X. This will be fine for most nights of good 'seeing.' A 2X Barlow takes you to 144X - which will need very good 'seeing' and is likely the maximum magnification of your scope.

So it really depends on what you are planning to use the scope on regards a Barlow being a good investment. But you don't "need" one as if you can't use the scope without one.

Clear Skies & Good Seeing,

Dave

[Dom1961]

Okay thanks! Ill probably get it as a later investment!