Focus Issues I have a Meade etx-125ec unit. I am unable to focus on any image. It appears the focus knob is loose and sloppy. It turns real easy and never gets the object in focus. Any suggestions on correcting this?

You can buy this device and take prime focus images using a small digital camera. Make sure the camera can take timed photos of up to 30 seconds long.

http://www.telescope.com/control/astrophotography/astrophotography-accessories/orion-steadypix-deluxe-camera-mount

There is a tiny set screw on the side of the knob. Make sure this is tight, and the knob is not just spinning around and around.

There is also a small rod inside -- that the focuser attaches to. If tightening the setscrew does not fix it, you will need to remove the focuser and see if it is detached from the rod. Make sure the scope is tilted BACK with the front of the scope UP a little or the mirror will slide to the front and possibly break.

This web site has lots of repair pictures--
http://www.weasner.com/etx/menu.html

The focus screw can come out if run too far. Point it straight up, give the side of the optical tube some light 'thumps' and turn the focuser clockwise. You should be able to see the mirror moving backwards in the cell.

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!

Here is the manual-- read it cover to cover--
http://www.meade.com/manuals/TelescopeManuals/ETXtelescopes/ETX-90%20w-autostar%20man.pdf

1. Take off the lens cap

2. Put your lowest magnification eyepiece into the telescope on the TOP eyepiece port-- there is a lever on the side which rotates the diagonal mirror between the top and rear ports --- can you see light through the telescope? If not turn the lever.

3. During the day practice focusing on a distant object at least 100 yards away-- the image will be upside down -- this is not a problem-- no UP or Down in space.!

4. The lowest magnification eyepiece is the one with the LARGEST number on it.

OK, that model has an internal adjustment. A good source for all kinds of information and tips on the ETX series is available from:
http://www.weasner.com/etx/menu.html

The focus knob can have the play reduced. Turn counter-clockwise a turn or 2, then loosen the knob's set-screw and carefully turn clockwise until a little drag is felt. Then tighten the set-screw.
A further item that may pertain to image shift, especially at low powers, is that the baffle tube that the main mirror slides on, may be loose in the back housing. There have been reports of poor thread engagement due to poor tolerences. That tube can be re-tightened - just be careful not to strip the threads!.

The ETX family (and other Meade LX telescopes), use a moving mirror system for focus. The focus knob moves the main mirror in and out. For smooth operation, there is some slack on the central tube that allows the mirror to rock slightly as it moves. That is a normal condition, and the movement is magnified, the greater the magnification of the eyepiece.

I think that the focus shaft has become un-attached by turning too far. Try placing the telescope facing directly upwards and start turning the focus knob clockwise. A little vibration on the tube will help the mirror to settle downwards. This may get the threaded rod back into the knob.

it could be the grub screw on the knob needs tightening. If it is loose, the knob will just turn but the shaft wont.