FOV of standard 25 and 10mm

[tallstevef]

Possibly very stupid question, but what is the FOV on the standard eyepieces you get with the Skyliner 200p?  Just want to get an idea of what I have currently, and to see (pardon the pun) how much wider some of the upgraded eyepiece options are...

[Galen Gilmore]

The telescope Magnification is your telescopes focal length divided by the eyepiece focal length. 

If you want to know the field of view then there is a FOV calculator at the top of the page, just go to >resources>Astronomy tools>FOV calculator. There you put in the telescopes and eyepiece information and it automatically generates a true to life field of view.

[ronin]

Don't believe they are plossl eyepieces any more, they used to be. So that means probably Kellners or Huygens, both of which a couple of pages say are 40 degree eyepieces.

To determine what you get work out the magnification: (Scope focal length)/(Eyepiece focal length) = Mag.

Then divide the Eyepiece FoV (40) by the Magnification.

So guessingt he 200P is an f/6, you have 1200mm so with the 25mm the Mag = 1200/25 = 40, Your FoV id therefore 40/40 so 1 degree.

The 10mm gives: 1200/10 = 120, View = 40/120 = 0.333 Degree.

For info a Plossl is usually 50 degrre eyepiece (some say 52 but 50 is easier to work through the numbers with, BST's and X-Cels are 60. ES make it easy.

[Littleguy80]

Assuming they're the normal 'Super MA' series eyepieces then it's 52 degrees for the 10mm and 50 degrees for the 25mm. That's apparent field of view.

http://www.rothervalleyoptics.co.uk/20802.html

 

[John]

As above - they are a modified Kellner design of 3 elements in 2 groups with around 50 degree apparent FoV's. With your Skyliner 200P the 25mm shows you a true field of just over 1 degree (around twice the apparent diameter of the moon) and the 10mm around .4 of a degree (a bit less than half of the moons apparent diameter).