Pentax scope Barlow lens problem (1 Viewer)

M

mikalm

New member

• Jun 3, 2007

• #1

I have a Pentax PF-65ED-A Angled 65mm ED Spotting Scope and I just purchased a Celestron Ultima 2x Barlow lens. With both of my eyepieces, a Hyperion 13mm, and a Pentax 20x-60x zoom, I am unable to achieve focus at infinity. There is not enough focus travel in the scope. Is this a problem with the scope or with the particular Barlow lens? Would a different Barlow lens work better? Is there another way to solve this problem?
Thanks for your help.
Michael Kalm

 

erniehatt

Well-known member

• Jun 3, 2007

• #2

I think you will find that Barlows are not meant for Spotting scopes. Ernie

 

M

medinabrit

Well-known member

• Jun 3, 2007

• #3

Barlows are for astronomical scopes not spotters .
Brian.

 

stuart C smith

swansong

• Jun 3, 2007

• #4

a barlow ! heavens above.

 

D

DRodrigues

Well-known member

• Jun 4, 2007

• #5

Only with Televue Powermates you will reach focus - the traditional barlows change the focus too much and birding scopes will not reach focus. For birding you should consider to buy another eyepiece instead of a powermate - the lowest increasing factor is 2.5x which means is not very usable for the zoom and for higher powers you probably would be better served with a Hyperion 5mm (if it reaches focus also) instead of buying the powermate and it will be cheaper.

David

 

M

mikalm

New member

• Jun 4, 2007

• #6

Responses

Thanks, all for your knowledge. I had no idea.
Michael Kalm

 

stuart C smith

swansong

• Jun 5, 2007

• #7

mikalm said:

I have a Pentax PF-65ED-A Angled 65mm ED Spotting Scope and I just purchased a Celestron Ultima 2x Barlow lens. With both of my eyepieces, a Hyperion 13mm, and a Pentax 20x-60x zoom, I am unable to achieve focus at infinity. There is not enough focus travel in the scope. Is this a problem with the scope or with the particular Barlow lens? Would a different Barlow lens work better? Is there another way to solve this problem?
Thanks for your help.
Michael Kalm

Click to expand...

if you unscrew the barlow lens from the body and screw it into the hyperion, chances are it will then come to focus.

 

D

DRodrigues

Well-known member

• Jun 7, 2007

• #8

Michael,

Just remembered that you might be interested in having a look at a Test of 2.5x magnifiers, on cr-telescopes at http://pt-ducks.naturlink.pt/

David