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eyepiece projection

Started by pf6500, 03/09/2014 07:59PM
Posted 03/09/2014 07:59PM Opening Post
I recently purchased an1.25 eyepiece projection eye piece
It seems i dont have enough in travel to come to focus.
Evev when i usr it in prime focus not enough in focus
It work if i use my 2x.barlow though it works.
Am i doing something wrong?
Any advice would be greatly appreciated
Thank you very much
Paul
Posted 04/02/2014 02:49PM #1
That seems to be a long focal length negative lens or a weak Barlow. Any Barlow will move the focal point back, but typical commercial Barlows provide too much image amplification for anything but lunar & solar system photography.
Posted 04/03/2014 08:28AM #2
A Barlow requires a significant amount of in focus. If it is working, I suspect your eyepiece should work.

Is there a possibility that you have removed the diagonal? If so, try it with the diagonal back in place. That may make the difference.

dan
Posted 04/13/2014 06:55AM #3
paul fields said:
It work if i use my 2x.barlow though it works.
Am i doing something wrong?
Paul

Paul,
You are not doing anything wrong, your setup simply does not have enough back focus to use the eyepiece projection adapter in the optical train you've configured. The 2x barlow you tried is likely one with a lense mounted at the front of the assembly, much like my 3x Televue, allowing it to extend the light cone through the optical arrangement you configured. I have an old 80mm Lumicon finder I use in a similar fashion. I can't use a diagonal with it for the same reason.

Since you did not give us any other details regarding the scope or the various piece parts in optical arrangement you are attempting to configure it is difficult to know what to suggest at this point. Let us know if you still need assistance.

-Gary
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