Re: ATM 6" f/8

[Larry Manuel <lmanuel@sprint.ca>]

Asaf S.-T. wrote:

> I'm very intersted in knowing what I'll be able to see with a 6" f/8
> telescope, with a:
>
> -1.52" diagonal,
> -1.75" diagonal,
> -1.3" diagonal?

I built my 6 inch f/8 with a 1.3 inch diagonal, and it worked like a
dream.  When I installed a 7/8 inch diagonal, I believe I could see
lower contrast planetary detail, especially when the seeing wasn't
excellent.  So, I think a small diagonal helps make the scope less
sensitive to seeing turbulence.

To summarize, I would never have known I was missing anything if I
didn't change to the smaller diagonal.  And I spent a lot of hours
peering intently at Jupiter and Saturn - otherwise I wouldn't have
realized the improvement.  Also, my scope was built with tons of tender
loving care, and was a truly optimized planetary Newtonian.  Sadly, it
was stolen 2 months ago.

The size of the diagonal is not nearly as important as absolutely
perfect collimation, for example.  Also eliminating tube currents is
more important.  The diagonal size is only a small part of the
performance equation [within reason].

Another good hint:  If you want to see more, observe more.  It works.

Larry.


--


lmanuel@sprint.ca
Larry [and/or Lynne] Manuel
Mississauga, Ont.

"Almost anything you do will seem insignificant, but it is most
important that you do it."
                                            --Mahatma Gandhi