New eyepieces wont focus!

[paul mc c]

Just got two new eyepieces and i cant get enough back focus,and the 35mm extension tube is to much what can some one suggest i do,can you get a smaller extension tube.

Paul

[TheThing]

Try just easing them out of the focused slightly until you reach focus. Don't forget to tighten the grub screw up again! Or use a Barlow. They move the focus point out. You can use it without the lens in as a shorter extension tube as well.

Sent from my GT-I9001

[paul mc c]

I have tried this Hugh but because they have under cut barrels the eyepiece doesnt sit central,i have tried looking for a smaller extension tube but can only find 35mm to be the smallest.

[John]

A par-focalisation ring fitted to the eyepiece barrels might do the trick. You can position that where you like. They have them on Astro Boot quite cheaply:

AstroBoot

[paul mc c]

Thanks John i thought about the rings,but with the under cut barrels on the eyepieces they may not fit,would there be such a thing as a high profile 2'' to 1.25 eyepiece adapter!

[John]

Yes, I have a thing called a "high hat" 1.25" - 2" adapter on my Tele Vue diagonal. There is something similar for £5 just over halfway down the Astro Boot listings.

Don't even ask how much the Tele Vue one costs !

[paul mc c]

Just recieved the adapter from Scope n skies astro boot that you said John, looks ideal

hav'nt used it yet but i think it is exactly what i was after and cridit to Scope n Skies they wavered the 10.00 postage for me so only cost 6.50 excellent.

Paul

[John]

I'm glad you got it OK but I thought that the standard postage for Astro Boot items was £1.50

£10 would have been a bit steep for an adapter

Hope it does the job for you

[paul mc c]

Out side the mainland they charge 10.00 postage:icon_eek: but after sending them an email saying that i thought it was unreasonable for such a small item they just charged me the 1.50 so well chuffed,thanks John.

Paul

[John]

Good for you Paul - I didn't spot that you are in Belfast

[ccdscopeman]

What about par-focal rings? Sorry, replied way too late on this one!

[garethmob]

from what i remember some ehyepeices have them already (certain sets) they basacally allow you to swap the eyepeices with minimul or zero focusing

[rwilkey]

The Baader FTR's (Fine Tuning Rings) come in two smaller sizes 14mm & 28mm, they work just as well.

[Moonshane]

Beat me to it Robin. Added to the 2-1.25" adapter and they extend out as much as needed from 14mm up. also prevent 2" filters being smashed by long nosepieces.

[paul mc c]

The strange thing is out of my 6 eyepieces the only one that worked was the 9mm BGO,so i would have needed rings for the other 5.

[rwilkey]

Moonshane, that's exactly what I use them for, never used them on a Hyperion ep, haha!