eyepieces question

[prbaxter]

whats the difference between 2" eyepieces and 1.25"?

and don't say 3/4"

Is there a technical advantage from either size?

[swamp thing]

I guess weight 1.25" tend to be lighter.

Cost too, the 2" tend to be pricier (more glass)

There is no difference in quality

Regards Steve

[brantuk]

Quality is determined by which make you choose to get. Televue figure at the top of range but they're expensive. The benefit of 2" is that you can get very nice widefield low power views of large objects like M31, M45 etc. some of which wouldn't fit in the fov of a 1.25". They do tend to be heavier (grenade like) having multiple elements for correcting light, so you may have to iron out balance issues on some scopes

[great_bear]

Heavier eyepieces also benefit from the greater strength of a 2" fitting. I think this is why some of the larger Explore Scientific eyepieces are 2" even though their field width doesn't require it.

[johninderby]

2" eyepieces are best for the longer focal lengths (17 to 20mm and above). At shorter focal lengths there is no advantage to using 2" eyepieces as the FOV wouldn't be any bigger than a 1.25" eyepiece.

So it's basically 1.25" eyepieces for higher powers and 2" for lower power widefield eyepieces.

John