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stupid finder tricks

Started by y, 01/11/2004 08:08AM
Posted 01/11/2004 08:08AM Opening Post
relatively new to this
so forgive the newbie comments.
loved the red dot finder on my celestron nexstar 114.
broke the piggy bank and got a nexstar 8
which comes with a 9x50 finder scope.

my small red dot finder
rarely lost alignment
and was easier to align (with 2 screws).
i really don't like the finder scope
as it seems like i'm always bumping it
and knocking it out of alignment
(just taking off the lense caps does it some times)
moreover i find it difficult
to realign in 2 dimensions with 3 different screws.

am i missing something here?
any hints on keeping the finderscope better aligned?
the screws are tight.
(i note that many in this forum like a finderscope and a red dot or telerad)


ok here's the trick:
lamenting the loss of my red dot finder
i was struggling to find a star
(had to crouch to see thru finder scope)
using non-dominant eye in finder scope
with dominant eye open to find star which wasn't even in the finder scope field...
voila
the cross hairs of the finderscope
were superimposed on the star
even though the star wasn't yet in the finderscope field!
i slewed the telescope to get the star in the finderscope
and suddenly i see a second (brighter image) of the star
in the finder scope moving more rapidly
and in the opposite direction (right to left)
as the first image.
i lined the finder scope image on the cross hairs
and was all set.

holy corpus callosum!
my brain superimposed the crosshairs from the eye with the crosshairs, but no star onto the field of the eye with the star but no crosshairs.

is this the way one's supposed to use a finderscope
or just a fancy parlor trick?

in any event it seems to me that the finderscope can be used like a telerad.

maybe i'll give the finderscope a few more tries
but i still like the red dot better.

thanks

bill

ps can anyone suggest a good forum for newbie comments like this?

Posted 01/11/2004 08:28AM #1
Interesting! I'll have to try that non-dominant eye trick. I sometimes wish my dominant eye wasn't SO dominant. Anyway, I recently added red-dot sights to 2 of my scopes, and like them so much that I'll probably add one to the others. On my smaller scopes, I'm using only the red dot. But on the larger scope I plan to use the red dot (circles, actually), to get me in the right vicinity, and then use the 50mm finder to really hone in on the faint fuzzies as best as possible before finding them in the eyepiece. I'm hoping that this will cut down on some of the progressive eyepiece changeouts that I'm currently doing.

You've found the right forum. Keep posting.
Mike Swaim
Posted 01/11/2004 09:37AM #2
Here are a few tips to get your finder lined up.

Sounds like your finder is loose in the mounting bracket. Make some "dimples" with a drill bit in the dovetail base where the mounting screws touch. This makes the mounting position consistent every time you re-attach it. Take your time and use a center punch before drilling to get them centered just right. Don't drill through, rather just deep enough to make a shallow hole.

Center the finder in the bracket with the front set of 3 screws. Make all your alignment adjustments with the rear set of 3 only. Leave the front ones alone.

Rotate the finder so the cross hairs follow the DEC axis... center a star and make sure it follows the cross hair when you tilt the scope up and down.

Good Luck
Charlie

Posted 01/11/2004 08:15PM #3
Hello Bill & all,

I have a Celestron C-8 SCT (f/10) and have found that I get good results from combining a Telrad with a very low power eyepiece. I use a very inexpensive 50mm Surplus Shed 2 inch eyepiece (I call it my "finder eyepiece"). It gives me more than a half degree field of view (2000mm / 50mm = 40 power). If the Telrad center circle (which is 0.5 degree)contains the object, then it is in the field with the "finder eyepiece" too. That has worked for me without using a finder scope at all. The Telrad has an intensity control and since it is "zero power" I look thru it with one eye and alternate opening and closing the other eye to see objects fainter than can be seen thru the Telrad's glass which attenuates some of the light. I don't have the blinking option, but have heard good comments about it helping see really dim objects. One final trick is that my observing buddy uses binoculars to look thru his Telrad to see both the dim objects and the Telrad circles at the same time. It works for him when he's looking for really dim DSO's.

Cheers,

Ed
Posted 01/12/2004 11:07PM #4