Nagler 31mm focuser in-travel requirement ...

http://televue.com/engine/page.asp?ID=144

The Nagler 31mm has the greatest focuser in-travel requirement of
..36", the 55mm Plossl the greatest out-travel requirement of 1.16" of
current TeleVue production. See column F in the link above.

The question is how other interesting oculars compare. Does the Nagler
31 demand the most in-focus of any ocular ever made, or is there one
out there even more severe?

This has important consequences when building a big dob, or any other
ATM project.

Doug Peterson wrote:
http://televue.com/engine/page.asp?ID=144

The Nagler 31mm has the greatest focuser in-travel requirement of
.36", the 55mm Plossl the greatest out-travel requirement of 1.16" of
current TeleVue production. See column F in the link above.

The question is how other interesting oculars compare. Does the Nagler
31 demand the most in-focus of any ocular ever made, or is there one
out there even more severe?

This has important consequences when building a big dob, or any other
ATM project.

The Speers-Waler WA's (particularly the 18mm, but all of them in
general) need more in travel than that.

Lawrence Sayre

--
My philosophy, in essence, is the concept of man as
a moral being, with his own happiness as the moral
purpose of his life, with productive achievement as
his noblest activity, and reason as his only absolute.

Ayn Rand (in the appendix to 'Atlas Shrugged')