Hi Dennis79,
Have you tried refocusing with the barlow in place? A barlow can significantly change the focal plane for an eyepiece.
If the focus lies further in than the draw tube can move, you will need to bring the primary mirror up closer to the secondary by adjusting the collimation screws, and then recollimate the optics. You would need a collimation tool to get the best results. Even if you don't raise the primary, properly collimated optics give the best possible image.
The only other alternative I see would be a new eyepiece to give you the higher power you are seeking. This is another reason I'm not a fan of barlows.
Other IISer's may come up with other suggestions.
|