Eyepiece advice

[Stargazer_00]

Hi guys,

I'm trying to work out what the view using this EP would look like..can anyone describe it to me?

I have a crayford focuser so I can squeeze a 2 inch in

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100 degrees FOV @ 9 mm.

I cant get my head around what this might look like in operation.. lets say for DSO. does this give a high mag but still show a wide field?

Confused... thought i sort of got it but this is such a wide FOV at a high mag.

[Capricorn]

The rule is eyepiece FoV/Mag.

So 100/(750/9) = 1.2 deg view.

Always struck me as odd as it is independant of 1.25" or 2" eyepieces, yet people all say that 2" has a wider view, an ES 100 degree eyepiece should give the same.

Basically means that with 83x Mag you could get all of the Pleiades in one view, similar with Orion Neb and I suspect most clusters, same for the moon. But Andromeda will still be too big to see it all.

One point that I have not met, but have read of, is that over 68 deg (no idea why 68) you may have to move your eye round to actually see large view you have.

By the way a 2" eyepiece is BIG.

[Stargazer_00]

Thanks

[brantuk]

Google 12dstring and CcdCalc - both free fov calculators for a range of eyepieces, cameras and scopes. I find both a good general guide for observing and/or imaging