Why am i getting a double image?

[Knightdragon]

Recently bought a telescope secondhand so no manual.

Been looking at the moon but last time i did some observations of it i was getting a slightly over lapping image, why? Do i need to clean eyepieces?

Also why using barlow x2 i cant get image of moon only a blare of colour.

My Barlow and erecting eyepiece are plastic, is it worth upgrading to metal ones?

Thanks to helpers.

[knobby]

What scope is it?

We can help you better if we know what you are using.

Quick thought,are you viewing from indoors through double glazing?

[Polar Bear]

Hi and welcome to the forum.

It would help if you tell us what make and type the telescope is and the eyepieces. Do they have any labels on them ?

If you have a refracting scope and are getting a double image either the objective lenses in the scope or the eyepiece may be mis-aligned.

Alternatively, if you have a reflector it may just be poor or misaligned eyepiece lenses.

Using a Barlow lens with amplify any optical problems you have.

Paul

[Polar Bear]

Quick thought,are you viewing from indoors through double glazing?

Good point and an easy mistake if you are new to observing.

Paul

[knobby]

Done it myself ;-)

[Spikey]

Welcome to SGL & I've edited your thread title in case someone starts singing. We don't want any more rain

[pixelsaurus]

All good points posted here. However my own personal experience was that I discovered that my right eye suffers from severe astigmatism. Years ago I used my 6" RFT Newtonian and a Meade Series 4000 25mm eyepiece ( magnification was 30x) and looked at the 2 Jupiters and their 8 moons. If the scope pans out ok then you may need to check your eyesight.

[knobby]

All good points posted here. However my own personal experience was that I discovered that my right eye suffers from severe astigmatism. Years ago I used my 6" RFT Newtonian and a Meade Series 4000 25mm eyepiece ( magnification was 30x) and looked at the 2 Jupiters and their 8 moons. If the scope pans out ok then you may need to check your eyesight.

Another another very very valid valid point point!!

[Knightdragon]

The telescope is a Seben Big boss 150, I am indoors but single standard window (old).

The eyepieces are a plossl 6.5 mm af 50 which I get no image through and the other is a plossl 25mm af 40.

[Cornelius Varley]

The telescope is a Seben Big boss 150, I am indoors but single standard window (old).

The eyepieces are a plossl 6.5 mm af 50 which I get no image through and the other is a plossl 25mm af 40.

Are you looking through an open ot closed window ? The glass will distort the light reaching the telescope and using a telescope indoors will also give you problems with warm air currents.

Are you using the barlow on its own without an eyepiece? A barlow lens is a secondary lens and is to be used in conjunction with an eyepiece. But not a 6mm eyepiece - this would give you too much magnification.

Seben telescope. You might want to do a forum search for that one.

Peter

[Brian Nordstrom]

Hi , as just said , if you are looking thru a closed window , that will give you the distorted images you are seeing , take it out side , or at the very least open the window .

Good old glass window panes are NOT!!!! optical glass and your scope wont perform looking thru one .

I think you will be very suprised when you take her out side and look at thge moon for the first time . At 1/2 phase .

Good luck , and please let us know how it all goes ?

Brian.

[Moonshane]

when you do take it outside, make sure you leave it for at least half an hour or so to get to ambient temperature. inadequate cooling is the most likely reason for your double image.

[Brian Nordstrom]

Good point . Well said , a large mirror takes a while to come to ambient temperature .

Brian.

[Knightdragon]

Hi Many thanks for the replies, i managed to get outside and got very good viewing of the moon, so it was the glass that distorted the image.

[knobby]

Result!