SILLY QUESTION

[lindon uk]

Hi all, would it be possible for someone to work out the magnification of my following eye pieces for me for my Skymax 127 goto :-

8mm ts planetary -

10mm plossl -

15mm plossl -

25mm plossl -

30mm plossl -

2 x barlow -

Thanks all ,Lindon uk.

[johnb]

Lindon

I think the following will help

The magnification of any telescope is given by this simple formula:

M = F(scope) / F(eyepiece)

that is, divide the focal length of the telescope by the focal length of the eyepiece using same units of measurement.

Example: telescope F = 1800 mm, eyepiece F = 2 mm, therefore magnification = 1800/12 = 150

However happy to be corrected

John B

[GazOC]

I'll show you how to do it yourself....;O)

The focal length of the telescope is 1500mm, just divide it by the focal length of the eyepieces to get the magnification. If you use the Barlow, multiply the answer by 2.

eg. 10mm Plossl = 1500/10 = 150 magnification (=300 with the Barlow)

[lindon uk]

Hi, just worked it out, simple lol, thankyou .

[MikeP]

Just looked at this so I could see my first silly question on the forum.

No, sorry it is not a silly question. We still have not had any. :)

Mike

[orionhunter]

on help forums, theres no such thing as silly question.

there maybe some silly answers though.

[yeti monster]

Always ready with a silly answer........

[Dimitris]

Agree with all previous answers, you should however bear in mind the limiting factor of "how many magnifications does your telescope can hold". As a thumb rule (and a very crude measure), multiply your aperture by 2 and there you have it. Which means that your 127mm telescope cannot go over 254 magnifications at best.

Therefore, GazOC's reply is corrcet up to the point of the 150 mag. Adding your barlow will double that (X 300) which exceeds you highest limit and you will be getting blurred image.

Regards

Dimitris

[GazOC]

To be honest Dmitris my post was just meant to explain the maths and general principle behind the question asked.

There will be be nights where that "limit" can be exceeded and x300 will not give a blurred image and nights where even x254 cannot be used.

[Dimitris]

To be honest Dmitris my post was just meant to explain the maths and general principle behind the question asked.

Sure thing! However, based on my expirience, people new in the hobby, tend to ignore the fact that the equtation has two parts. In most of the cases it has to be reminded. Several times. No offence meant, I just stated the obvious

There will be be nights where that "limit" can be exceeded and x300 will not give a blurred image

That, my friend, I still have to see to believe

Regards

Dimitris

[GazOC]

The equation doesn't have 2 parts, its just:

Telescope focal length/ eyepiece focal length = magnification.

Your opinion on the maximum the scope or conditions will handle is not part of the equation.

(The scope will hold x300 on very good nights on double stars and the moon IMHO)