Using finder scopes

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  • Member since
    July, 2013
Using finder scopes
Posted by SWA Pilot on Tuesday, January 14, 2014 8:34 AM

I bought my first telescope, a Celestron AstroMaster 114 EQ, the other day.  My question is, how do I use the included red-dot finder scope better?  Last night I tried my best to get the dot over M42 in orion.  Everytime I thought I had it I would look through the lens and nothing.  I finally found M42 by shear luck, and the view was amazing.  To me the dot just seems so large compared to the object that I am trying to place it over, and if my eye isn't perfectly aligned there are two red dots.  I know part of the problem is experience or, in my case, lack there of.  The other part of the problem is I am use to binoculars with fields of view of 4.7 and 6.8 degrees and need to get used to a telescope with a field of view of around 1 degree.  Any help would be greatly appreciated.

Well boys, we got three engines out, we got more holes in us than a horse trader's mule, the radio is gone and we're leaking fuel and if we was flying any lower why we'd need sleigh bells on this thing...

 

Canon 10x30mm Image Stabilized, Celestron Cavalry 15x70mm, Oberwerk BT70, Oberwerk 25x100mm Deluxe, and Steiner 10x50mm binoculars

Celestron AstroMaster 114 EQ telescope

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  • Member since
    October, 2007
Posted by zachsdad on Tuesday, January 14, 2014 8:52 AM
The problem may be that your finder is not properly aligned with the optical axis of your scope. To correct this, take the scope out during daylight hours and select a distant fixed object, like the top of a telephone pole, or radio antenna, then find that object through the eyepiece. Center the tip of the object in the eyepiece view and then look through the finder, if the object is not centered in the finder use the adjusting screws on the finder to adjust the position of the red dot until it is on the target. As for the size of the dot, I'm not sure what the problem is with that, unless the brightness of the dot is adjustable and is turned up too bright. At night you will be able to get by with a very dim dot. Good luck. I hope this helps.

Terry's Law of Cosmology: "Light travels faster than sound. That's why some people appear bright until you hear them speak."

18" Obsession Classic dob #1665

10" Orion Skyquest Classic dob

 120mm Orion ST achromat

15 X 70 celestron Skymaster binoculars

  • Member since
    March, 2008
Posted by Antitax on Tuesday, January 14, 2014 11:49 AM

   Zachsdad said it right. I'll only add the daytime target must be very distant, at least a kilometer, or the angle between the finder's line of sight and the scope's line of sight is large enough to make you miss your mark at higher powers. Don't worry, the finder's alignment is among the most routine questions beginners ask, and easily fixed.

   EDIT: By the way, since your newtonian is new you might need to collimate it, which will change the mirrors' aim. In this case you will have to reset your finder to match it.

TS 8x40 Wildlife, 10x50 Marine/Fujinon 16x70/TS 80mm triplet, 6x30 finder, EQ-3 mount, TS 2" 99% diagonal/Celestron C5+ and 6x30 finder, DIY tripod/5" Bahtinov/12" GSO dob, 8x50 finder/Meade 2" 24mm 82°/Hyperion 24,13,10mm 68°/TS Expanse 17mm 70°/SW 7mm Panorama 82°/Ultima 2x barlow/Astronomik UHC-E filter/Baader O-III/Astro Solar 5" & 80mm filters/Sky Atlas 2000/Rükl's Moon Atlas/Canon 400D/5mW green laser

  • Member since
    July, 2013
Posted by SWA Pilot on Tuesday, January 14, 2014 1:11 PM

So much to learn, so much to learn.  Thanks for the inputs.  I think practice will also help.  I did not receive my wings on the first day of pilot training.

Well boys, we got three engines out, we got more holes in us than a horse trader's mule, the radio is gone and we're leaking fuel and if we was flying any lower why we'd need sleigh bells on this thing...

 

Canon 10x30mm Image Stabilized, Celestron Cavalry 15x70mm, Oberwerk BT70, Oberwerk 25x100mm Deluxe, and Steiner 10x50mm binoculars

Celestron AstroMaster 114 EQ telescope

  • Member since
    July, 2013
Posted by SWA Pilot on Tuesday, January 14, 2014 3:44 PM

I checked the alignment this afternoon.  I focused on a water tower about 2 to 3 miles away.  Centered in the scope and same for the finderscope.  I just think I just need more practice.

Well boys, we got three engines out, we got more holes in us than a horse trader's mule, the radio is gone and we're leaking fuel and if we was flying any lower why we'd need sleigh bells on this thing...

 

Canon 10x30mm Image Stabilized, Celestron Cavalry 15x70mm, Oberwerk BT70, Oberwerk 25x100mm Deluxe, and Steiner 10x50mm binoculars

Celestron AstroMaster 114 EQ telescope

  • Member since
    January, 2014
Posted by h panday on Saturday, January 25, 2014 4:21 AM
The same problem I also faced with my Celestron 130EQ.. I suggest that you purchase one or two low power eye pieces. I purchased a 32 mm one. With that your field of view will increase. Then by keeping that in centre increase the power by changing the eye piece from low to high one by one while every time bringing the object in the centre of the field of view.
  • Member since
    July, 2003
  • From: Eastern SD.
Posted by johnjohnson on Saturday, January 25, 2014 12:00 PM

I would add a right angle correct image (RACI) finder scope. It will provide a FOV like a binocular at 8X mgnification and 5.4 degrees. This may require you to drill 2 small holes in your optical tube though.

Then use your red dot finder to get in the general area of the object of interest, then go to the RACI finder scope to cross hair the object, then to a low power 32 or 26mm eyepiece in the main telescope.

RACI Finder Scope

It's an added expense but well worth it in the long run and you can transfer it to another scope if you upgrade in the future.

JJ

20" F5 Obsession, OMI mirror .987 Strehl. 10" F4.7 reflector. 6" F5 ST reflector. 120mm F7.5 EON. 80mm F11.3 guide scope. SkyWatcher EQ-6 Hyper Tuned.   Flicker Astro Site   More Astro Images

  • Member since
    October, 2005
Posted by leo731 on Monday, January 27, 2014 3:53 PM

Yes.  JJ has the very best set up in regards finders.

The reason some of us prefer RACI finder scopes is that they are far more comfortable to use when looking overhead.  My neck, back, and knees are very thankful as I can sit and simply move my eye from the finder to the main eyepiece at any position.  One more little trick for EQ mount users is to align the crosshairs in the finder to the movement axis of the scope.  This makes it far easier to center what you have found as the scope's movement in both axis mirrors the lines of the crosshairs.

L

L

A nebula in the eyepiece is worth two in the Atlas.

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  • Member since
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  • From: PA, USA, Earth Moderator
Posted by DaveMitsky on Monday, January 27, 2014 10:05 PM

RACI finder scopes certainly do have their advantages.  However, with a strategically-positioned straight-through finder scope it's possible to look through the finder scope with one eye and at the sky with the other.  Any object that is visible to the naked-eye can be lined up to coincide with its image in the finder scope.  The object should then be within the field of view of the main telescope.

Dave Mitsky 

Sic itur ad astra!

Chance favors the prepared mind.

A man is a small thing, and the night is very large and full of wonders.

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