Re: diagonal focus

I just bought a new FS-78 and I am using a 2" televue diagonal and there is not enough "in focus" to focus with an eyepiece of shorter focal length than 8mm. An 8 mm Radian will just barely come to focus but a 7mm Pentax XL won't come to focus...and none of the eyepieces will come to focus with a 2x barlow...kind of exasperating when you figure all the time and money involved getting a new scope mounted and up and running and then discover that you can't get over 78x when using the 2" set up....and if you want to use shorter focal length eyepieces you must take off the 2" diagonal and the 2" ocular adapter,then put the 1 1/4" ocular adapter back in and then install a 1 1/4" diagonal...all this just to up your magnification..and then if you want to put in a long fl eyepiece again you gotta go through the process all over again...in the dark nonetheless...

David,

This recessed adapter would probably do the trick (bottom of the page on this link):

http://www.astrosystems.biz/focm1.htm

Of course, you might run into the problem of eyepieces and barlows with long tubes hitting the diagonal mirror.

Joplin

David,

Interesting...I use my TV everbright inserted into the Tak compression ring 2 in adapter and with the 1.25 - 2 Adapter come to focus with all of my eyepieces including the 5.2 and 7 XLs and all of the Tak LEs. It is very close when using the TV hi hat adapter, but you pick up a comfortable amount of in focus with the new TV flat top adapter. Unfortunatly I can not use my CAA with the 2 inch adapter. That is frustrating because I love using the CAA to rotate the daigonal.

I forgot to mention that was on my FS-78. I do not have any problem with my FC-100 even with the CAA as long as I use the flat top adapter.

John