Can't get 8" Dob Telescope to focus

[EdgeFU]

Hello,

I've purchased an Celestron 8" Skywatcher Dobsonian telescope which comes with two eyepieces 10mm and 25mm with an adaptor and finderscope.  I took the telescope outside to just look at the moon and found it fine with the finderscope.  I checked the main scope and all I saw was white light coming through.  I turned the focuser slowly, but kept seeing the same thing, just white light.  I was not using the adaptor at all, just the 25mm eyepiece.  Any help would be appreciated as to what I am doing wrong.

Thanks.

[Paul73]

First thing to check is that the telescope (main tube) is fully extended. It may seem obvious but they often have an interim stop 3 or 4" from the fully extended position. Not sure why, but it often catches people out.

Correct not to use the adaptor. This isn't an extension tube. You replace the black eyepiece holder with this to accept 2" wide eyepieces.

Hope that this helps.

Paul

[Marky1973]

If your focusser is anything like the one on my 200p dob, there is also a small locking screw in the underside....if the focuser isnt moving, check that this isnt tightened.....I fell for that first time out!

[EdgeFU]

First thing to check is that the telescope (main tube) is fully extended. It may seem obvious but they often have an interim stop 3 or 4" from the fully extended position. Not sure why, but it often catches people out.

Correct not to use the adaptor. This isn't an extension tube. You replace the black eyepiece holder with this to accept 2" wide eyepieces.

Hope that this helps.

Paul

Paul,

I thought maybe that was the case, but was afraid to extend it too far and end up breaking it, but with your tip, I went back and tried it and found that just after the first click where I would stop it previously, it would do a second click into place.  I do not have time to try out the viewing until tomorrow night, but this would seem to be the resolution to my issue.  Thanks so much for the info and it doesn't help that the instructions tell you to extend until you hear a click to remove the guard over the top of the tube, but fail to mention to extend it further when viewing.

[EdgeFU]

If your focusser is anything like the one on my 200p dob, there is also a small locking screw in the underside....if the focuser isnt moving, check that this isnt tightened.....I fell for that first time out!

Yes, I had this problem the previous night and figured out the screw was keeping it from telescoping in and out.

[Paul73]

It should look like is at the bottom of the sliding struts.

Paul

[EdgeFU]

Thanks for all the help.  I extended the telescope completely tonight and was able to view a very sharp detailed version of the moon (it was in 1st quarter).  Also I tried to find the Orion nebula and it didn't look to impressive just like a few stars with a cloud around them.  Lastly, I saw Jupiter as a ball of light in my 25mm and then switched to the 10mm and saw some bands and its moons.  Looks like my problems are now solved.  Now to find more to look at in the sky.

[Kirscovitch]

Try cranking up the mag on M42. It's pretty spectacular under some higher mag and you can make out the trapezium.