Info required please

[totalamateur]

Does anyone know how to calculate what magnification an eyepiece will give????????????????.

My scope is a 127mm ED APO TRIPLET f/7.5

[Jamie]

Try this web page.........Just fill in your details to generate the correct calculations...

Magnification & Field calculator

[haitch]

If you'd like to know long hand (and if I understand myself! )...

Your f ratio of 7.5 is the focal length divided by the aperture (127mm) so if you multiply the aperture by the focal ratio you get back to the focal length. The magnification of an EP is the focal length of the scope divided by the the focal length of the EP (remember to be consistent with your units).

So in your case 127mm x 7.5 = approx 930mm focal length

So for simplicity a 10mm eyepiece...

930/10 = 93

A magnification of around 90 times.

[totalamateur]

Thanks for your responses guys, you've been very helpfull.

Regards, Ray