Eyepiece sizes.

[Johnny Thunder]

Could someone please explain the differences and advantages/disadvantages of 1.25" and 2" eyepieces please.

Thank you.

John.

[GazOC]

1.25 eyepieces are smaller and lighter, but in wider eyepieces a 2" format is needed to show the full view.

[Johnny Thunder]

Thanks Gaz.

Does this mean that bigger is not always better, or should you always buy 2" if it is available?

[John]

Thanks Gaz.

Does this mean that bigger is not always better, or should you always buy 2" if it is available?

For high and medium power eyepieces there is no advantage in the 2 inch size IMHO. For low power eyepieces the larger barrel size allows a wider field of view, eg: in the 1.25inch fitting a 40mm eyepiece can only have a 43 degree field of view wheras a 40mm eyepiece in 2inch size can have a 70 dregree FoV.

The above is mirrored in what's on the market - relatively few medium to high power EP's in the 2 inch size but lots of low powered ones.

John

[MikeP]

Have a look at what is said here ... http://www.cloudynights.com/item.php?item_id=366

Mike

[Johnny Thunder]

Thanks guys, that helps.