setting up scope

[mxmick]

Hi All, I just set up anew scope for my daughter (and myself too if I`m honest!) Its an inexpensive newtonian reflector scope. The view we have has got a circle and three lines like a gunsight coming out of each object we look at. The first time we looked at Jupiter we thought it was an UFO but unfortunately its not! Have we done something wrong in the setup or is this the way the telescope is?

[brantuk]

Which scope make and model is it Mick? You could be out of focus if you can see the spider arms in the eyepiece. What sizes are your eyepieces?

[mxmick]

Its a National Geographic 525. I tried the three eyepieces; 20mm 4.5 and 12mm, the spider vanes are visible in all three.

[brantuk]

Well it's a 76mm aperture scope. The adverts seem to suggest "525x power" but I doubt it - I think that refers to the focal length of 525mm but correct me if the instructions say any different. The eyepieces will give the following magnifications:

20mm = 26x, 12mm = 44x, and 4.5mm = 116x magnification.

Start with the lowest one (20mm). You'll need to adjust the focuser knob very slowly across it's entire range till you find the point at which you get a sharp image. Best to try it on the moon first cos it'll be easy to find,

These scope are notorious for arriving with poor collimation. This is the process of lining up the mirrors properly. If you can still see the spider vanes at the best view you can find then it will need to be collimated.

If you look in the eyepiece and take it slightly out of focus first inward then outward a mm or two, you should see fuzzy rings of light around the object - they should be concentric if it's collimated well.

Let me know how you get on with that we can take it from there

[brantuk]

One other thing - the mount tends to be shaky on these - you'll need to tighten up all the bolts till they are firm but allow smooth firm movement (eg for spreading the legs out). To make it a bit more stable hang a weight under it from the tray

[mxmick]

Thanks Brantuk,

Just had a great view of Mars there. Everything is a bit fiddly with the scope but even with these minor problems, it really is cool to identify these planets for the first time. It seems that I will have to collinate, I will try tomorrow evening, I can see where this hobby could be quite addictive!

Thanks again

[brantuk]

You're welcome Mick - let me know how you get on with it