Magnitude in telescopes

1. Aug 19, 2015

Sobhan

what is the difference between linear magnitude and angular magnitude

2. Aug 19, 2015

davenn

never heard of either in reference to telescopes
and I have used scopes for best part of 50 years

3. Aug 19, 2015

Sobhan

my question is this:

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4. Aug 19, 2015

Staff: Mentor

Wait, do you mean magnification, not magnitude?

5. Aug 19, 2015

Sobhan

Sorry i meant magnification.

6. Aug 19, 2015

Staff: Mentor

Angular magnification is what our eyes or a lens see, whereas linear magnification is what is projected onto a surface, so it is measured linearly.

See (second section):
http://hyperphysics.phy-astr.gsu.edu/hbase/geoopt/lensdet.html

Since this is a telescope question, I'm moving the thread to that section.

7. Aug 20, 2015

Sobhan

the other question i have got is: where do these formulas like field of view and .... come from

8. Aug 20, 2015

davenn

I assume you mean, how is it calculated ?

cheers
Dave

9. Aug 20, 2015

Sobhan

What is the prove of that FOV?

10. Aug 21, 2015

Staff: Mentor

It's derived from basic trigonometry. The angles and objects form triangles.