viewing with a barlow lens

[Neptune38]

Hi all, i've finally managed to get my scope out tonight for the first time, i can see the stars through the 25 EP as points of light, ,but after i attached my barlow lens directly onto the scope, in front of the diagonal, all i can see is total darkness, am i doing something wrong, Advice please 

[ronin]

Use the 25mm eyepiece to find a bright star, Capella, then try the barlow.

The focus will change but Capella should be bright enough to still be visible but out of focus.

When you add or change anything at the focuser you will have to alter the focus a little or a lot.

This happens on eyepieces that are supposed to be par-focal also, those are not bad but equally not perfect either.

This is one reason for people getting a family of eyepieces such as all BST's or All X-Cels, less adjustment when changing over.

I suspect that the stars you have in view are simply sufficently out of focus that they do not apper bright enough to register.

OOPS, barlow goes after the diagonal and in front of the eyepiece.

I need to learn to read. :help:

Scope-diagonal-barlow-eyepiece.

[rockystar]

I think you have put the Barlow between the scope and the diagonal at should go between the diagonal and the eyepiece

[Stu]

Yes, putting the Barlow in front of the diagonal will increase its multiplying factor making things dimmer, and may make focus impossible to reach.

Get it after the diagonal, with the eyepiece in it and then try on a bright star.

[laudropb]

The Barlow fits into the diagonal, then the eyepiece into the Barlow.

[Staffs Oatcake]

Lol. I tried a Barlow last night and soon found that what I thought would be centre eyepiece was nowhere near when the Barlow was applied. Fortunately I was viewing M42 , so it's glow crept into the eyepiece allowing me to re-centre the eyepiece

[LukeSkywatcher]

The Barlow fits into the diagonal, then the eyepiece into the Barlow.

Obviously not all types of scopes use a diagonal, so if the scope you (anyone) uses does not use a diagonal..........the barlow should be placed directly into the focuser and then the eyepiece goes into the barlow (as normal).

Just thought i'd mention this so there is no confusion.

Lots of questions about barlow's tonight from people with new scopes.

[Neptune38]

Yes, putting the Barlow in front of the diagonal will increase its multiplying factor making things dimmer, and may make focus impossible to reach.

Get it after the diagonal, with the eyepiece in it and then try on a bright star.

Yes, that's why i put it in front of the diagonal, still it's a learning process, i'll keep at it, i couldn't align it with Polaris this evening, as it wasn't in view from my garden. Is it normal for the stars to appear as a point of light with not much detail? Thanks.

[Stu]

Yes, that's why i put it in front of the diagonal, still it's a learning process, i'll keep at it, i couldn't align it with Polaris this evening, as it wasn't in view from my garden. Is it normal for the stars to appear as a point of light with not much detail? Thanks.

Stars will only ever appear as points of light as they are so far away. The interest from stars comes from different colour contrasts, double or triple stars plus open and globular clusters.

[Neptune38]

Stars will only ever appear as points of light as they are so far away. The interest from stars comes from different colour contrasts, double or triple stars plus open and globular clusters.

I did notice that a particular star i was viewing, had a blue glow to it, no idea what it was, i was just scanning around randomly and thought i would focus on it,  what with it being my first proper night out with my scope, are there any particular stars that have a blue glow to them?

[N3ptune]

You can check the spectral classification on the link bellow to understand the temperature of various stars. Class A - B - O are quite blue with really high temperature like 10 000 kelvins.

An interesting exercise would be to compare Sirius which is a A0 star type, blue  (7500 ~ 11000 kelvins) and Betelgeuse which is a M2 star type, red (3500 Kelvin)

https://en.wikipedia.org/wiki/Stellar_classification