Eyepiece adaptor

[Steve_meg]

My friend has just Got himself a Meade 4505 which uses 0.965 eyepieces. He asked it it was worth getting a 0.965- 1.25 adaptor.

I said it would allow him more choice of eyepiece but it would reduce the FOV of the 1.25 eyepiece.

Would it still be worth while? Or is there a better way round it?

[Peter Drew]

It will only reduce the field of eyepieces that have a field stop greater than .96" which won't be many.

[NGC 1502]

I've seen .96 to 1.25 adapters. When using 1.25" eyepieces in the adapter, you will probably find that the field of view would be restricted for low power, probably around 25mm or greater.

From around 20mm focal length or shorter, you will probably see no vignetting because the eyepiece field stop will be smaller. But there are no guarantees, you would need to try to be sure.

The other (possible) problem could be achieving focus. The adapter will place the eyepiece further out, so you would need to rack the focuser further in. You would need to try it to see if you have enough in-focus movement on the focuser.

If there is not enough in-focus, there are dodges to sort that.

It could all work fine of course, apart from the likely vignetting (darkening of the edge of field) at low power.

Hope that helps, Ed.