ok question???

[leanneblues]

the telescope i have when i put the 6mm eye piece on it just goes all blurry is that the telescope or the eye piece,what im saying is if i buy better quality eye pieces will i have the same problem because the tetelsocope isnt powerful enough ior will better eye pieces make a diffrence at the min iam looking at the moon through a 12mm and it looks fantastic but now i want to see more

I LOVE THIS!!!!!feel like shouting to the worl whatout there lol

[Ant]

No offence is intended in the question below,

Unless the Ep's are parfocal you'll have to re-focus when you change between eyepeices?

If you are re-focusing then it could be partially down to Collimation, the general observing conditions at the time.

Ant

[Jamie]

Hi Leanneblues. (not trying to be too pedantic here)

You will have to re focus when you switch eyepieces

The only thing i have noticed when you use more powerful eyepieces is that

the focusing sweetspot is a little more difficult to atain.

You will find that you will pass the focusing point very quickly.

In saying that i can only advise that you slow down when focusing.

HTH...

[GazOC]

Also the higher the magnification the more careful you have to be to focus, the 'sweet spot' gets smaller.

[leanneblues]

hi yeah im re focusing but nto getting much joy and have done it very very carefully,

it doesnt seem to want to go far enough (moving wise of the eyepiece)to be able to focus if that makes sense,just been looking at this scope anyone know if its a good un for the money

http://www.celestron.uk.com/catalogues/view_item.asp?CatalogueID=272&CategoryID=3762&ItemID=30592

[Ant]

OK, you say that EP doesn't want to go far enough - which direction... do you need to move the EP closer to the scope or further away?

Ant

[barkis]

It might help if you said what telescope you are using. ie. what is the focal length, and what size is your lens/mirror.

A 6mm eyepiece is a very strong magnification, particularly if the size of the objective is quite small.

Usually eyepieces are supplied with telescopes and are conducive to the instrument, but not always.

You often find in adverts for telescopes, wording like 600 times magnification. Well in theory, you can magnify as much as you like, but you won't see anything, because the mirror/lens can't deliver enough light.

Jamie has probably answered your question though. focusing is very critical at powers delivered by a 6mm E/P.

Ron.

[leanneblues]

im moving it closer to the scope if i bring it out i cant see a thing

[leanneblues]

its not an expensive telescope its a optus reflector telscope here is the detaisl of it

Technical Data: Focal Lenght is 700 mm mirror diameter is 76 mm. Magnification : Eyepiece 20 mm .. 35 x, eyepiece 12.5 mm ... 56 x , eyepiece 6 mm ... 116 x,

[Ant]

The next time your out, try removing the diagonal and trying again. This may help in finding the issue...

It will tell you if it is an EP issue or a back focus issue.

If it's an EP issue then a better EP might help, or just more care and time spent focusing - alter the focus very slightly each time and wait for the vibrations to die down before checking, adjust again etc etc etc.

If it's a back focus problem, a barlow might be the answer - as the focus position moves OUT when you add a barlow. Or buy a better EP.

Ant

[leanneblues]

thanks any but can i ask what does moving the diagaonal mean???

[John]

its not an expensive telescope its a optus reflector telscope here is the detaisl of it

Technical Data: Focal Lenght is 700 mm mirror diameter is 76 mm. Magnification : Eyepiece 20 mm .. 35 x, eyepiece 12.5 mm ... 56 x , eyepiece 6 mm ... 116 x,

My guess is that your problems with the 6mm eyepiece are a combination of i) a low cost eyepiece (I think you said in an earlier post that the ones you are using now came with the scope) ii) the fact that 116x was just too much power for your 76mm reflector on the night you were using it and iii) the scope is possibly a bit out of collimation which means that the mirrors are not aligned properly which happens quite easily to newtonain reflectors, especially if they have been posted !.

For now I would settle for using the lower power eyepieces and read up on how to check to see if your mirrors are aligned OK (try googling "newtonian collimation"). You might also have a carefull look at your 6mm eyepiece to check that it's lenses are not very dusty - if you bought the scope 2nd hand it might have been in storage somewhere.

In your scope I reckon 120-140x would be the absolute maximum you can use, even on a really good night and with a good eyepiece.

John

[jimlennie]

just been looking at this scope anyone know if its a good un for the money

http://www.celestron.uk.com/catalogues/view_item.asp?CatalogueID=272&CategoryID=3762&ItemID=30592

Hi,

A 90mm refractor will give you better views than your present scope can manage but if I were you I would invest that budget by using it to buy this :-- http://www.firstlightoptics.com/proddetail.php?prod=dobsky150

This 6" reflector is Dobsonian mounted and will be easy to use and transport about. The views that this scope will provide will be a major upgrade to what you are seeing now. This scope will collect 4 times more light than your present reflector and will allow you when seeing conditions permit to magnify up to 300x and still keep a bright image.This scope will cost the same as the refractor that you are interested in after SGL discount. The 6" Dob's mirror is figured at F8 which means that collimation ( mirror alignment ) will be much easier to attain and will also be more forgiving of slight mis-alignment. At F8 you can also use less than premium quality eyepieces to attain nice sharp stars across 90% of the field of view. Finally, if you decide later on to get into astro imaging you can mount the ota ( optical tube assembly ) onto a equatorial mount simply by buying the mount along with a pair of tube rings.

Hope this helps, I know how difficult it is when you are starting out and if you are spending your hard earned cash wisely !!

Jim

[The Warthog]

I second Jim's motion, Leanne. I would suggest that the Skywatcher 6" Dob is a very good little telescope indeed. A friend of mine has one, and is a very experienced observer, and doesn't use anything else. He has two eyepieces and a Barlow, each of which cost about as much as his scope, and gets very good views.

My 6" Newtonian gives me very good views. Even with standard Plossl eyepieces, I can see anything within the range of the scope. The eps that are supplied with this scope are standard plossls, and you won't need to replace them for a while.