eye piece help

[Si Rollett]

Just got my first scope and am thinking i am going to have to get a book for newbies.

In the mean time i got a 10 and 20mm eye piece with my scope and was wondering about trying to get more, not sure what each size is used for or even if i can get others for it. Really new to this as you can probable tell.

[The Warthog]

First read the sticky "Eyepieces - the very least you need." This will give you some clue as to what to get. The focal ratio of your scope is f/10, and the 10mm eyepiece will give you 70x, while the 20mm will give you 35x.

If your eyepieces are slightly less than an inch in diameter, write us back. Otherwise you should be able to get a good idea of what you need from the sticky.

[Si Rollett]

Read it but Im really so new to this i got lost in it but think my scope is a f13 which i think means i don't know. I think i maybe just being thick. I think i know that the 10mm one gets closer. So lost

[John]

I think your scope is an F/12.9 and has a focal length of 900mm. The 20mm eyepiece gives 45x and the 10mm one 90x. The if you want to add some eyepieces I think a 32mm plossl (cost around £30) plus a 7.5mm plossl (cost around £20) would be useful additions. With the eyepieces you already have these additions would give you 28x (wide field / low power scanning), 45x, 90x and a top magnification of 120x which is about as much as your scope can usefully use.

[The Warthog]

The specifications for that scope from a Canadian supplier say 700mm, and f/10, but their copy could be wrong. Whatever, John has given you a good suggestion for a set of eps that will give you a good range of magnifications.

If you still feel lost, keep asking questions until you find your way.

[John]

....If you still feel lost, keep asking questions until you find your way.

Definitely do this

The world of eyepieces is more confusing than the world of scopes in some ways - almost too much choice

[Si Rollett]

Thank you all the box said f13 so that's what i went with hope its right. Sorry for being a pain, i will crack it soon, Im one that learns by doing. Can't wait to get there but thinking it might take a while.

[Si Rollett]

Just looked on the celestron web site and it is f13 with a max 165x and min of 10x does the right angle adapter (diagonal) change anything?

[The Warthog]

Just looked on the celestron web site and it is f13 with a max 165x and min of 10x does the right angle adapter (diagonal) change anything?

OK, then, the advertising copy that I read was incorrect. Still, 165x is a bit optimistic, and 120x would seem a bit more realistic. The diagonal adds nothing but some extra ease and comfort in viewing, expecially on objects at high altitudes.

[Si Rollett]

With the tripod it came with everything is at high, with out it I think I would have to be lead down on the floor.

[The Warthog]

With the tripod it came with everything is at high, with out it I think I would have to be lead down on the floor.

Exactly!

[Si Rollett]

Just looked on the celestron web site and it is f13 with a max 165x and min of 10x does the right angle adapter (diagonal) change anything?

Can you add some thing to the diagonal to bring the ep up to make it easier to view at high angles?

[Tribal-Wolf]

Can you add some thing to the diagonal to bring the ep up to make it easier to view at high angles?

The diagonal is for high angles, you could try sitting on a chair.

[Si Rollett]

I take that's a no i will maybe need to look go to another pod. As at really steep angles the seat is to high. Will have to look around at stools.

[rory]

im afraid you have to be preparded for some unique positions when looking high up with a long refractor, many a night on all fours when looking toward the zenith.

anyway, i agree with a few others, a nice low power eyepiece is a good way to go, forget trying to get high magnification . a 30-32mm vixen, meade,gso ect would be a great addition and i wouldnt bother with much more than x100 in that scope, mines a 90mm version of the same make, and i found high mag was nice for the moon ,but not much else as it becomes dull and washed out. where as my 32mm meade (x31.5) is my most used e/p no question. good for locating and observing the brighter dso's.

good luck with the scope...

[Si Rollett]

So 30-32mm is the highest you think i should use in it? Won't buy till i have taken it out somewhere darker after i have moved, have mainly looked at the moon so far as i am not sure what other things are ment to look like, if you get what i mean.

[The Warthog]

I solved my problem with the height of the refractor on the tripod by building a taller tripod. Before that, I had considered getting three 8" concrete blocks and putting the legs of the tripod on those. If you can leave the concrete blocks in place, that could work for you.

[rory]

remember the higher the number in mm,the lower the magnification. so a 10mm eyepiece will be more powerful than say a 20mm eyepiece,but with lower power generally you get a sharper, brighter image,so with a small apeture its always a good bet. a 32mm e/p in your scope would give something like x28 . ( you divide the e'p number by the focal length of the scope) in you case i think its 900 divided by 32. so you can figure out any mag now.

[Si Rollett]

I solved my problem with the height of the refractor on the tripod by building a taller tripod. Before that, I had considered getting three 8" concrete blocks and putting the legs of the tripod on those. If you can leave the concrete blocks in place, that could work for you.

Was thinking blocks because i could make little holes so it gets the same place every time.

[Si Rollett]

remember the higher the number in mm,the lower the magnification. so a 10mm eyepiece will be more powerful than say a 20mm eyepiece,but with lower power generally you get a sharper, brighter image,so with a small apeture its always a good bet. a 32mm e/p in your scope would give something like x28 . ( you divide the e'p number by the focal length of the scope) in you case i think its 900 divided by 32. so you can figure out any mag now.

What's the lowest you put in yours for the highest usable mag.

[rory]

ive used up to 6mm (x166) but it aint good (apart from the moon)

if you could get a e/p in the range of say 26-32mm as a low mag e/p, and 8-9mm top end mag maximum. an 8mm will give about 112x .

also high end magnification requires good seeing conditions, which isnt too often,so im told !

[Si Rollett]

Cheers 8mm max unless its the moon then 6mm max and anything up to 32mm

[rory]

one other thing, if youve a small plastic red dot perspex typr finder built on to the telescope,you'll find its next to useless.so a low mag e/p would act as a finder too.

[Si Rollett]

Any ep makes i should avoid and which ones are good to go for?

[rory]

Cheers 8mm max unless its the moon then 6mm max and anything up to 32mm

this is my opinion and im nowhere near as knowledgable as many on here, its just what i learnt as i went along.

good luck ,and ask away if theres more you need to know.theres some really knowledgable folks on sgl:)