20 Most Recent Bushnell NorthStar 78-8831 (525 x 76mm) Telescope Questions & Answers

http://www.manualslib.com/manual/23358/Bushnell-78-8831-78-8846.html?page=10#manualOn the northstar base

Astronomical telescopes show a upside down image. For terrestrial use, you can buy a erect image eyepiece. They are not made for astronomical use since they reduce the light and contrast.

This telescope uses 1.25 inch eyepieces. Comes originally with a 20mm and a 4mm (probably cheap modified acromats) The 4mm would exceed the maximum practical magnification. 50x per inch. Many eyepieces available on Ebay and telescope vendors. If the 20mm is missing, buy a 20mm Plossl. I prefer other designs focal lengths under 12.5mm because of the eye relief. Agenaastro makes great, inexpensive ($55). I like the Sterling Plossls from Smartastronomy too Eyepieces for planetary viewing I suggest the 5.2mm for your high power or a TMB planetary (Astronomics has them for $50 Get the 5 or 6mm Clear Skies!

It's the same as a camera lens eghttp://www.usa.canon.com/app/html/EFLenses101/lens_care.html

I had the same problem. I removed the motor and drive assembly and used a pair of pilers to gently rotate the drive gear a few times in both directions. I re-installed it and it began to work again. I also noticed that the grease on the drive gear and shaft was very thick. Cleaned and up and re-applied a lithium based grease and it helped even more. Be sure to remove all old grease from the aluminium block that the drive gear shaft rest in. Good luck.

Remove the 3 screws holding the black cover on the mounting arm. Gently tighten the lock nut until you achieve the required resistance but not too much that motor won't function. I found less that 1/8th of a turn was enough.

Mirrors are way out of alignment. Your manual does not have "collimation" instructions. I do not know if the user can align the mirrors. If not I suggest you return the scope and get a comparable scope from Meade, Celestron or Orion. If your scope can be aligned, follow instructions at link provided below http://www.skyandtelescope.com/howto/diy/3306876.html

Maximum magnification on a perfect night is 150x with this scope meaning the 4mm supplied is worthless unless looking at the moon 700/4= 175x mag. Your scope may be out of optical alignment. Look in the manual for instructions on collimation or search the net for detailed instructions. I suspect the spider image may just be poor optics. If you are talking about 4 spikes at 90 degrees from each other radiating from the object, that is the spider vanes that holds the secondary mirror. Higher end reflectors have much thinner vanes to minimize this

Contact Bushnell here:

http://www.opticsplanet.net/bushnell-warranty.html

All astronomical telescopes show upside down and or inverted images it is completely normal.

Nothing is wrong with the scope as their is NO up or down in outer space.

1. use the lowest power eyepiece (highest number in mm)
2. Point the scope towards a object (about 1000yds) away during the day and see if you can focus on the object. If you can not see anything during the day there is a problem either with the scope or set-up
3. Align the finder to the daylight object so it is ready for night viewing.
4. First night object should be the moon. Easy to find. ( A full moon presents poor seeing but this is just to get used to the scope.
5. Once the above steps are completed, use a good star program to find interesting objects (Stellarium, Cartes du Soliel, C2A are all freeware)
6. If you can not see the daytime object, remove the eyepiece and look down the focus tube. You should see a reflection of your eye in the primary mirror. If not, the primary and/or secondary mirror need to be collimated (aligned) refer to your owners manual.

This can be caused by many things-- such as dirt or grease on the encoders inside or a slipping clutch. I know you just bought this telescope, but Bushnell is NOT KNOWN for having quality telescopes.

To get the goto to work everything must be according to the manual.

The tripod needs to be perfectly level-- time, date, and site must be accurate, and the alignment objects must each be centered in the eyepiece. Sounds like you also have electronic issues with the hand controller. Only Bushnell can repair this scope.

All astronomical telescopes show upside down images-- it's normal. NO up or down in space!

Read my tips on my profile page-- especially the Frequently Asked Questions TIP.