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I have the Minolta ompact 8 by 25...6.7" When I turn the centre knob to focus nothing happens. The r eyepiece focuses ok. I removed the centre screw...it appears that the bottom of it is broken?

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  • The Master
  • 6,215 Answers

Needs servicing, mending or replacing

Posted on Nov 21, 2019

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6 Suggested Answers

6ya6ya

6ya staff

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Posted on Jan 02, 2017

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Anonymous

SOURCE: ETX-90 Focus

I suggest trying a different eyepiece first to see if that's the problem. Otherwise, if it was moved without adequate protection, there is a chance the mirror was shifted or damaged. A damaged mirror can't really be fixed since it's specs are very rigid. If it turns out to be a problem with the mirror the best thing to do is find an expert on telescope mirrors to try and fix the problem.

Posted on Nov 12, 2007

Anonymous

  • 2 Answers

SOURCE: focuser broken

Not really a solution, but anything is better than a posting that get's NO response. It sounds like the rack and pinion drive has collapsed. If you're good with your hands and have a knack for things mechanical maybe you can dissassemble the stage mounting and see how it's meant to work. If something has come loose rather than broken maybe you can fix it. If teeth have stripped from the drive gear - you may be unable to effect a repair. I guess trying to fix it is better than doing nothing. Have a good 2008

kevin

Posted on Jan 12, 2008

Anonymous

  • 30 Answers

SOURCE: Microscopes

Well then ?

It sounds like you do have a pre-tension problem, and if the fine focus is slowly turning as the stage desends, that is where your problem is. If you could tell me make and model, fixing it should be no problem.

Regards.....Dave

Posted on Mar 10, 2008

Anonymous

  • 1 Answer

SOURCE: Focus knob screw

I've had the same problem. Unfortunately, these are knock-off scopes. If the shaft that the focusing knobs attach to is still there, you can replace the knobs themselves by ordering THIS part. If the shaft AND the knobs are both missing, you'll have to replace the entire focusing mechanism (sorry, but I don't know where to order the housing from). Hope it's more helpful than the prior answer.

Posted on Jun 24, 2008

GeoffW1

Geoffrey White

  • 3961 Answers

SOURCE: focus knob turns but nothing moves

The Celestron manual for this scope has nothing to say, but on the underside of the focuser assembly, between the 2 focus knobs, you may see 2 screws.
They might be thumbscrews or some other screwhead type. One is the adjustment for the focuser internal clearance, or looseness, and the other is a focus travel lock.
If present, try backing both off 1/2 turn from tightness, and then experiment to see which is which. The focus lock will have no effect until tight, when the focuser will cease moving, as is now. The other screw will gradually remove looseness and rattle from the focuser until it just moves smoothly, with no back and forth loose feeling at the knob.
If neither of these screws is visible you will have to take it to a binocular and telescope shop, where they should not charge much.

Posted on May 06, 2012

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1 Answer

Focus knob turns but nothing moves


The Celestron manual for this scope has nothing to say, but on the underside of the focuser assembly, between the 2 focus knobs, you may see 2 screws.
They might be thumbscrews or some other screwhead type. One is the adjustment for the focuser internal clearance, or looseness, and the other is a focus travel lock.
If present, try backing both off 1/2 turn from tightness, and then experiment to see which is which. The focus lock will have no effect until tight, when the focuser will cease moving, as is now. The other screw will gradually remove looseness and rattle from the focuser until it just moves smoothly, with no back and forth loose feeling at the knob.
If neither of these screws is visible you will have to take it to a binocular and telescope shop, where they should not charge much.

May 02, 2012 | Celestron Optics

1 Answer

Hello, I have a celestron c9,25. I adjust a nikon D3100 with T-Ring and Adapter to my telescope. Firstly I focus to moon, using an eyepiece, then I removed the eyepiece and adjusted the Nikon. The...


Because the camera has a different focus point from the eyepiece. TURN the focus knob until the camera comes into focus. OR you can buy a "focus ring" for the eyepiece which attaches to the barrel of the eyepiece and is adjustable-- then focus with the camera FIRST and then insert the eyepiece with the ring on it and lift it UP until the image comes to focus-- then tighten the ring. NOW you can use that eyepiece to roughly focus the camera.

Jun 25, 2011 | Celestron C9.25-CF 2350mm f/10 Aluminum...

1 Answer

Ihave bought Nextstar SE4. I aligns and moves but i cant seeanything from the eyepiece. In day light i can see brightwite background but no image. Please help


Put the eyepiece with the largest number written on it into the focuser. This is your lowest magnification.

During the day time point the scope at a distant object and practice focusing -- you may need to turn the focus knob several times right or left to achieve focus.

It will focus if you turn the knob enough.

Jan 14, 2011 | Celestron Optics

1 Answer

I culmated my telescope and cant' get it to focus in. Using the focuser the image stays one big blob without any distinguishing figures.


Did you put an EYEPIECE into the focuser? Probably NOT.

Take the scope out in the day time, put the eyepiece with the largest number written on it into the focuser. Practice focusing on a distant object. TURN the focuser knob slowly until the object comes into sharp focus.

Sep 15, 2010 | Orion SkyQuest XT6 Classic Dobsonian (354...

1 Answer

Can not focus telescope lens pieces do not fit


What Tasco do you own is it a refractor or reflector? Does it have a lens in front -- then it's a refractor; or mirrors, then it's a reflector.

On a refractor the eyepieces go in the back of the tube, sometimes you also have a diagonal which goes into the scope first and then the eyepiece goes into the diagonal. The diagonal is simply an L shaped device with a mirror inside that makes it easier to look through the scope when it is pointed UP at an angle.

On a reflector the focuser is on the FRONT side of the tube, and the eyepiece goes into the focuser.

Take the scope outside during the day time and practice focusing on a distant object. Put the eyepiece with the largest number written on it into the focuser or into the diagonal. This is your LOWEST magnification.

Practice focusing --- until you get used to how it is done. Turn the focuser knob to the left slowly-- if nothing comes to focus then try turning it to the right. It may take several full turns to come to focus.

At night the moon should be your first target.

Read my TIPS on my profile page.

ABOUT NOT FITTING: eyepieces come in 3 sizes, .975, 1.25, and 2 inch sizes. Measure the hole and then measure the eyepiece-- it may be that you have the wrong size eyepieces for that scope. The correct size can be purchased on line from many retailers. Here is one telescope retailer that sells eyepieces and other accessories:

http://www.agenaastro.com/

Jul 29, 2010 | Tasco Optics

2 Answers

Seeing double when I look with both eyes. Out of


Step 1.
Adjust the eyepiece or both if both are adjustable back to zero. It should be printed on there. If it's not, then halfway. To find halfway turn them to one end, count the number of turns like 1 and a half turns for example, and then half that atnd turn it that ammount. You've now reset the binoculars to zero.

Step 2.
Now to focus. Pick your target that you want to look at thoguh your binoculars. Look through the binoculars and close the eye with the adjustable eyepiece or your right eye if both are eadjustable and focus the image on the left eye with the central focus knob. Once you've got it focused close the left eye, open the right eye and if it's not in focus adjust the EYEPIECE focus, not the central one, until it's in focus.
If you can't get it in focus because the eyepiece focus won't turn far enough in one direction, turn the OTHER eyepiece in the opposite direction at max, start the process again from step 2.

If it's all ok now you need to adjust the distance between the eyepieces. Open the binoculars as far as they go, look through the binoculars with both eyes on the target and move the binoculars inward slowly until you remove any black edges around the image, then move them very slowly inward until you see only one image.

If you've got more problems come back as ask. :-)

Nov 27, 2009 | Vector Audubon 8x42 Binoculars

3 Answers

Can't focus my telescope


If there is nothing on the objective lenses or eyepiece lenses then it most likely needs collimation. This is where you adjust the secondary mirror while viewing an out of focus star. You need stable sky conditions to do this.

There are most likely three small screws at the front of the telescope and these are what you use to adjust it. As one screw is loosened then another is tightened. Do this in very small increments. If you have your manual it should outline how to perform this. If not go to this web site: http://www.astrosurf.com/legault/collim.html. It will show examples of how objects look both in and out of collimation. There is a section further down the page for SCTs.

A very handy tool for this is to replace your screws with Bob's Knobs (http://www.bobsknobs.com/) . These replace the screws and allow you to adjust it by hand instead of a screwdriver.

The other focusing problem I've experience with my Celestron SCT is to have the focus knob loosen up and then slip as I turned it so that I could never focus with it.

Good luck and clear skies!

-jodair

Mar 29, 2009 | Meade Optics

1 Answer

Etx cant focus


The LPI camera will HIGHLY magnify the image-- about like a 6mm -8mm eyepiece-- tiny adjustments are needed to focus. You can buy a .5 or .3 focal reducer which will widen the field of view and make it easier to focus--

On my LX90 --- it takes about 20 TURNS of the focus knob to go between the eyepiece view and the camera view!

Jan 11, 2009 | Meade ETX-125EC (500 x 127mm) Telescope

1 Answer

Inoperative focus control


I'm assuming this is the Maksukov-Cassegrain telescope. Turning the focus knob CW should get you focus at infinity by moving the primary mirror away from the eyepiece. As you turn the knob it should move in and out relative to the real of the scope. If that's not happening the focus screw may have been turned CW too far and no longer be catching the threads in the rear plate of the scope.

You may be able to get it to rethread by holding the front of the scope toward the ceiling and turning the knob CCW. Attached is a photo of what the scope looks like under the rear housing. To prevent the focuer shaft from turning in too far the knob should be firmly seated agains the rear of the shaft. I think on this model this is a friction fit.

HTH, George
7793c63.jpg

Jan 23, 2008 | Optics

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