Saturday, January 16, 2016

''Hind'' Newtonian Telescope on 23-rd December 2015

This is the Newtonian telescope built by my friend Tavi aka Erwin  around mirrors made by David Hind from UK.
Specifications  : 
-primary mirror diameter = 158mm 
-primary mirror focus 1240mm
-secondary mirror m.a. = 32 mm
-DIY Dobsonian mount :all the parts ( except optics ) were 
made ,adapted ,adjusted and  assembled by Tavi.

Here we see Tavi at an outreach sponsored by ''Resita TV''  at Resita .
This action happened at the launch  of a TV documentary intitled ''On the footsteps of the first astronomers'' hosted by Marc Francu.

I'm having the honor and pleasure to use and test this telescope for a while.

Here follow some observations made by myself with the ''Hind'' 158mm Newtonian on 23-rd of December 2015.
I used deliberately Galilean oculars on the first test.
Their resolution and contrast on stellar objects is very good and  the sky background is very dark.
The Galilean  oculars are doing justice to the resolving power ,to the definition and penetration capabilities of the telescope.
However this type of ocular is very unfriendly and unforgiving to the user.
(So here is my advice ; ''don't do it at home'' unless you are a perfectionist freak! )
One was a Galilean ocular with a focal length of - 50mm sent by Carol , my colleague from ''60mmtelescopeclub''.
In order to reach the focus , I had to use my Japanese  2 x Barlow lens ,which in this case , become a 3x Barlow lens.
The magnification of this setup was 74 x.
The other ocular used on this test was a Galilean ocular with a focal length of - 9mm providing a magnification of   138 x .
The Galilean - 9 mm ocular is reaching focus.
This ocular was made by my friend Silviu aka zoth.

In a few words : excellent telescope ,very good optics , reliable   mount !

''The Celestial Passion'' by Richard Watson Gilder