[AZ-Observing] Another form of Telrad style reflex finder
- From: gene lucas <geneluca@xxxxxxxxxxxxx>
- To: AJ Crayon <acrayon@xxxxxxx>, AZ-Observing <az-observing@xxxxxxxxxxxxx>
- Date: Mon, 21 Apr 2008 22:14:20 -0700
There is a second form of "Telrad" style reflex finder available, the
Quickfinder from Rigel Systems:
http://members.cox.net/rigelsys/rigelsys.html
http://members.cox.net/rigelsys/quikfinder.html
(Sold by various dealers.)
The Quickfinder uses the same reflex or "HUD" (Heads Up Display,
reflective beamsplitter window) principle as the standard Telrad, but is
arranged as a more compact, upright gadget, in which the reflective
window is farther away from the telescope tube. I have one of each
(Telrad and Quickfinder), but have not made any comparisons re: visual
star brightness, so I can't comment on that.
My two non-astronomer friends indicated they could not get the standard
Telrad (on the SAC Loaner Scope, a Pierre 6 inch) to work properly for
them -- they were pretty disappointed in it. I did notice it is mounted
pretty close to the tube (baseplate adapter mounted right on the tube),
and requires really straining your neck to get your eyeball aligned.
Maybe it's just the small size of that 6 inch scope. The brightness
adjustment seemed to be working ok. Of course, if the brightness is set
anywheres near bright enough to see or check the projected reticle in
the daytime, it is way too bright for night use.
A long time ago I made a zero-power, tube style "bean shooter" sight for
my 8 inch Meade 2080 SCT (now nearing its 25th anniversary), and then
realized, I didn't really need the full length tube, so I cut the whole
thing down to its essentials. The aiming sight consists of two sets of
white PVC rings (carefully cut from plumbing tubing scraps with a
hacksaw), drilled and mounted on standoffs -- screws and spacers
(washers) -- fore and aft on the tube. (There are convenient tapped
holes on the SCTs that allow aligning the rings.) The spacing (about 13
inches, the length of the SCT tube) between the two sets of rings gives
a good field indication, which I could actually calculate the angular
size of, if I was so inclined.... On a standard scope, you could adjust
the spacing between the two sets of rings to give a particular field,
based on the diameter of the tubing used. No lighting is needed (no
battery to run down), and therefore, no loss of night vision. The white
PVC rings stand out clearly against the sky. The back one (nearest your
eye) has two concentric rings: a larger outer one, and a smaller inner
one for centering. (Spaced apart with washers on the mounting screw.)
The one on the far end has a post that sticks up to the center of the
ring. You sight the front post through the smaller centering ring in
the back, and point the scope to have the object of interest behind the
post. (You really only need the centering ring and a post, I
suppose....or maybe just two posts fore and aft, sticking up... probably
a bit dangerous in the dark!)
Biggest issue for me is that I am near-sighted, so I need to wear my
glasses to be able to see both sets of the sighting rings and also the
stars. Therefore, I am constantly removing and replacing my glasses,
for infinity vs. eyepiece views... Ditto, have to re-focus the
conventional finder optics.
The "Starlite" adjustable brightness LED astronomy flashlights by Rigel
Systems are absolutely THE BEST I have ever found, in 50 years
observing! (Sold by various dealers.)
http://members.cox.net/rigelsys/flashlight.html
Gene Lucas
(17250)
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