Question about Celestron NexStar 4 SE Telescope

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Black dot. Why is there a black dot on every star i look at. Please help i am a beginner with telescopes

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Ensure focusing is spot on. if your image is a black dot surrounded by white light (like a doughnut) then your not in focus. Look at making a Hartmann Mask (really easy, just google for it), which fits over the front lens. It has 2 or more holes in it,this means when you look through the eye piece you will see double images, adjust focus until the images merge into one (if the images go further apart turn the focuser the other way), when they are merged remove the mask and presto you should be in optimum focus. Always remember telescopes are very sensitive and focussing requires delicate adjustments.
Regards and Clear Skies

Posted on Mar 12, 2008


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Why can I not see the difference from the sky and a star even when I allign my laser well?

It sounds like you have not adjusted the focus properly. I recommend you take your telescope outside in the daytime and point it toward a building or tree or hilltop that is somewhat distant from you. The exact distance is not important, but it should a block or more.

With the telescope pointed at the distant object, focus the telescope until the object is sharp and clear. The object might appear upside down -- that's normal for many astronomical telescopes. When you have achieved a sharp focus, leave the focus control alone until you are outside at night under the stars.

The focus should now be fairly close for viewing stars and planets. Small adjustments of the focus control may still be necessary for the sharpest view.

- Jeff

Jun 08, 2014 | Celestron NexStar 4 SE Telescope

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After i remove all the appropiate lens caps and align the red dot, i cant see anything out my lens except darkness. Total black background,day and night. Should i try something else,thanks.

Put the eyepiece with the largest number written on it into the focuser, do not use the 2x barlow. TRY AGAIN-- during the day time and practice focusing on a distant object.

The end with the FOCUSER is the UP end of the tube-- the mirror is on the bottom of the tube. Many beginners mount these BACKWARDS.

Jan 07, 2011 | Celestron AstroMaster 114EQ (100 x 114mm)...

1 Answer

There was no instrucitons manual on how to put the lens together and see put of the lens and also there was no cd like it said on the box .

Here ?r? a few web pages w?t? ?οοd information ο? beginner's telescopes:

Fοr more advanced information, read Phil Harrington's Star Ware, 4th edition (Wiley).

Dec 27, 2010 | Tasco Novice 30060402 (402 x 60mm)...

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Telescope is definitely assembled correct but fail to see any magnification of light thru tube with use of either lens. Very clear nite but little moonlight, does that matter? Seems we get no magnification...

Did you try this during the day time. Stars are always just points of light no matter what telescope you use.

Try for the moon and or Jupiter which is up in the sky right now after dark. It looks like a BRIGHT star.

Dec 27, 2010 | Vivitar (1607225) Telescope

1 Answer

I have a Meade EXT90. A black dot appears in the middle of every object I view (Jupiter, Mars, etc) with the exception of the moon. Any ideas on waht that might be? Thank you.

The black dot means you are way out of focus.

In an ETX90 Mars will always be a TINY disk, except under extreme magnification.

Jupiter is also a small disk but a little bit bigger.

Next time you try for Jupiter focus on the MOONS until they are tiny points of light like little stars.

Also certain eyepieces have this as an unwanted trait. Try another eyepiece -- start with the one with the largest number written on it which will be your LOWEST magnification.

Sep 08, 2010 | Meade ETX-90EC (325 x 90mm) Telescope

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Bought the tasco 525 x 60 used and all we see is black. looked up and down for something obvous and can't find it?

Did you try focusing during the day time on a distant object?

Objects in the sky are very tiny, smaller than the tip of your finger held at arm's length. The scope must be pointed directly at them to see anything----- and your scope also has a VERY small field of view. That's why we recommend binoculars to a beginner. The wider field of view makes it easier to find objects in the sky at night.

Download this free monthly star chart:

Locate a local Astronomy club and attend their star parties and meetings. They will help you.

Read my tips on my profile page for more information.

Sep 02, 2010 | Bushnell Tasco Telescope Galaxsee 525x60mm...

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How I know the red dot is working ok, is

This is a 60mm telescope not much bigger than a 10x50mm pair of binoculars. Your maximum magnification will be about 100 power. Yes I know they said 200-300 power on the box. This was a lie.

Do not use the 2x barlow. Probably be just too much magnification. Put the eyepiece with the largest number written on it into the telescope; then try the same eyepiece with the 1.5x barlow. That is probably all the magnification the scope can handle.

Stars are always pinpoint light sources, no matter how large the telescope. They are hundreds or thousands of light years away.

The "red dot" should be pointed at exactly the same spot as what is in the eyepiece. Center a bright star in the eyepiece, then without moving the telescope... center the red dot on the star. Now you can use the red dot to POINT the telescope exactly to a sky object.

This web site may also help you:

Dec 28, 2009 | Konustart 700 (120 x 60mm) Telescope

1 Answer

Cannot see through lense

A telescope only shows about 1 degree or LESS of sky-- this about the size of the tip of your finger held at arms length! Point it at the moon and practice focusing the telescope.

Dec 25, 2008 | Tasco Galaxsee 45-114375 375X (375 x...

1 Answer

Dot in view

Sounds like a collimation problem!! do you know how to collimate the optics?

Jul 08, 2008 | Bushnell NorthStar 78-8846 (675 x 114mm)...

2 Answers

Viewing planets and stars

The problem is you are way out of focus. Turn the focus knob alot, until the star image gets much much smaller. Keep going until it looks like a pin point or a star!. The spider vane and center black dot will disappear. This black dot is actually the secondary diagonal mirror reflection in the primary mirror. The peace signs are the secondary supports. Use the lowest power eye pieces. I would not use the Barlow lens that comes with this scope as it very poor quality. Also, using this high power with this small an aperature (tube diamter) & unstable mount will be very difficult indeed. Invest in some wide angle, long eye relief low power lens. Use these for a while before going to higher powers.

Nov 19, 2007 | Bushnell NorthStar 78-8831 (525 x 76mm)...

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