newbie needs advice

[liphook]

This is my first post so be nice please.

my wife has a SkyWatcher 114 telescope, f/5

She has the current optics - Barlow x2 , super 25 wide angle long eye relief, super 10 long eye.

we have been using the barlow and the super 10 to look at the moon, but are unsure of what each lens is for, when do we use the super wide 25?

do you have the barlow in at all times?

we would like to purchase some other optics as well, she wants to see more detail, what can you reccomend please for someone on a budget

would this scop see the rings of saturn with the right optics?

all help is appreciated.

[sunshine185]

If you use the 25mm, it is not as high magnification, so you will get a wider view of the moon. The Barlow lens simply magnifies things by 2 , so if you use the 25mm with the barlow it would be like having a 12.5mm eyepiece. Try the 25mm on its own on the moon, you will probably enjoy the view better than the 10mm and the Barlow. And no, you do not have to use the Barlow at all.

[sunshine185]

Saturn, I am not too sure tbh, you would be better trying the 10mm on its own our the 25mm with the Barlow.

[Northern Soul man]

Hi Ya Liphook and welcome to the SGL, not sure but you might struggle to see the rings of Saturn with the scope you have, using the Barlow and the 25mm eyepiece with a relatively short focal length (f5). when you start using eyepieces with a smaller number on the side of the eyepiece - the views of the moon are ok because its very close and very bright - but when you start observing the planets - they are a lot smaller and fainter and using the eyepiece with 10 on the side may give the view of Saturn as a disk but the rings may not be visible as "rings" but as an extension of the planet - especially if you use the 10 and the barlow together to increase magnification this will degrade the view of Saturn to a fuzzy blur - not sure about this Liphook as I have never owned the scope you'll have to wait for more members to reply - but I'm sure the Moon looks fantastic - Take care and Clear Skies. Paul.

[liphook]

thanks for the reply, will try the 25 on its own and compare the two.

are there any optics that would give me more options?

[brantuk]

You have the newtonian version of this scope with a focal length of 500mm. Divide this by the size of the eyepiece (eg 10mm) and you have a magnification of 50x. That's just using the eyepiece on it's own. If you slip the barlow in between the scope and eyepiece it will double this to 100x magnification. To see saturns rings a magnification of around 150x would be very nice with a good eyepiece

(You can do this sum with any eyepiece)

[umadog]

We are always nice here! Welcome!

The magnification produced by an eyepiece is the telescope's focal length divided by the eyepiece focal length. For example, you scope has a focal length of 114*5=570 mm so your 10 mm eyepiece yields a magnification of 57X (570/10=57). The 25 mm provides a lower power but a wider field of view (you'll see more sky).

The barlow lens has the effect of doubling the telescope's focal length so your 10 mm eyepiece will yield (570*2)/10=114X when the Barlow is used. Put in the barlow when need the higher power. If you want lower power don't use it.

Your existing eyepieces will be quite sufficient to show Saturn's rings. You will see the rings quite distinctly and clearly with that scope, but will appear small.

The maximum useful magnification of your telescope is limited by atmospheric conditions and the size of the mirror. In practice a telescope can only be push to around 30X per inch of aperture, although instruments with good optics and good skies can go to 50X or even 60X per inch. Thus, you can realistically expect the maximum useful power to be in the region of 130X to 200X. Your 10 mm with Barlow basically takes you into this territory. Perhaps an 8mm or 7mm eyepiece will squeeze out a little more detail (when barlowed), but probably you're good as you are for now.

[ollypenrice]

To find the magnification you are using just divide the focal length of the telescope by the focal length of the eyepiece. If you add a 2x Barlow that magnification will double. You will probably find that, for the moon and planets, a maximumum magnification of around 200 is the highest that is worthwhile. Less might make the image smaller but sharper. However, larger, fainter objects can look best at about 15x magnification, which is less than you can manage at the moment.

It is a popular misconception that telescopes are there just to make small things look larger. Often more important in astronomy, they also make faint things look brighter. this is where your longer focal length eyepiece comes in. Use it for larger 'deep sky' objects like nebulae or the wonderful Andromeda galaxy or open clusters like the Pleiades.

Your scope will show (and very very easily) the rings of Saturn.

Olly

Edit, sorry, similar posts came in while I was typing.

[sunshine185]

Liphook, user the 25mm and have a look at pleaides, it will look magnificent in your scope. If you are having trouble finding it, download a program called stellarium for the pc

[liphook]

thanks for the replies guys, its interesting, but confusing reading for a newbie like me.

so is an 8mm optic worth getting? is that the best i can get with this scope? or are there other options?

[umadog]

You'll find eyepieces spanning the 10 mm to about 4 mm range in about 1 mm increments. You may find an eyepiece in the 8 mm to 6 mm range to be handy but I wouldn't say it's necessary. With a 7 mm, for instance you will get 163 X when barlowed. If you want to experiment look around for one second hand and sell it if you don't like it. It won't cost much this way. Alternatively, find a local club and people will lend you stuff to try out. Short focal length eyepieces of the Plossl design work well and aren't terribly expensive.

[liphook]

You'll find eyepieces spanning the 10 mm to about 4 mm range in about 1 mm increments. You may find an eyepiece in the 8 mm to 6 mm range to be handy but I wouldn't say it's necessary. With a 7 mm, for instance you will get 163 X when barlowed. If you want to experiment look around for one second hand and sell it if you don't like it. It won't cost much this way. Alternatively, find a local club and people will lend you stuff to try out. Short focal length eyepieces of the Plossl design work well and aren't terribly expensive.

I will try a 7mm optic and see how that goes, any suggestions of where online to get a cheap/used one?

i have seen some optics up to 40mm, when and why would you use that?

[brantuk]

You'd use sizes over 25mm to 40mm for wide field views of large objects like andromeda galaxy, double clusters, orion nebula, etc. You'd use maybe an 8mm or 10mm on planets, maybe a 5mm or 4mm for splitting double stars.

But that's not definitive - just a rough guide - you'll get a gradually beter feel for what eyepiece to pick as your familiarity with the sky and scope improves

[umadog]

You could look here for second hand: U.K. Astronomy Buy & Sell

Meade Series 3000 (discontinued?) or 4000 Plossls may be good bets. Celestron also make a similar range. You could call up Telescope House for advice. They currently selling a 6.4 mm Meade Plossl for 30 quid: Meade Series 4000 Eyepieces

You will see more expensive eyepiece designs out there too. These typically have a wider field of view than a Plossl. This is achieved using more glass, often high refractive index glass, and this costs more. A good Plossl can provide very sharp views but its more simple design makes the field of view more narrow. This is worth knowing since, although Plossls are cheap, you're not necessarily giving up optical fidelity. Instead, you're giving up optical bells and whistles.

[liphook]

seen these from whats been recommended, can someone advice as to if they are decent.

Bresser 4 piece eyepiece starter scope upgrade kit

[AWR]

seen these from whats been recommended, can someone advice as to if they are decent.

Bresser 4 piece eyepiece starter scope upgrade kit

I wouldn't to be honest.

Personally I think you'll get better upgrading and expanding your eyepieces one at a time. If the 10mm and 25mm are the same which came with my SW127 Mak, I found the 25mm much better quality than the 10mm. I'm not sure about the quality of the barlow lens but I've heard disparaging things about the ones Skywatcher supply with the scope.

First up magnifiaction, as others have said, is calculated by dividing your telescope focal length (500mm) by the focal length of the eyepieces. The barlow lens will double the magnification, but if it is of suspect quality, that may not help much.

For Saturn, an EP of about 5 or 6mm FL should give a good view (or a 10mm with a x2 barlow). Try your 10mm with your barlow first up. If that's not up to much have a look for a 5 or 6mm EP on its own (rather than a kit).

Again as others have said, try your 25mm on its own on the Plieades.

Have a look here: http://stargazerslounge.com/beginners-help-advice/80772-eyepieces-very-least-you-need.html

Andrew

[liphook]

advice taken on getting a single lens.

regarding looking at pileades, i can only find the moon at the moment, not sure how to find others yet

[umadog]

Get yourself a copy of Turn Left At Orion. Worth its weight in gold when you're starting out.

[sunshine185]

Have you downloaded stellarium yet? This will tell you where things are in the night sky.

[ryan]

Hello Liphook,

I am fairly new to this as well.

I have a Celestron 130EQ and i use Plossel eyepieces 25mm,10mm, 6mm. and a barlow

I find they are all that I need for the scope I have.

sunshine 185 is right definately download stellarium its very simple to use and you soon find your way around the skys.

The problem I find is not the eyepieces for viewing Saturn but not having a motorised mount makes it harder to get Saturn in view for a reasonable length of time, you have to keep adjusting the scope but it is still worth it.

We all have to start somewhere and the advice on this site is not a bad start.

Good Luck.

[Cashman]

I've got the same eyepiece set with my skywatcher 130p. The Barlow is the worst piece in the kit. It turns any view into to blurred mush. I would advise trying to manage without it.

[todd8137]

i gave the stock barlow away i tried a few till i found a Tal x2 barlow and its the best i found

[liphook]

are these the plossl that are recommended?

Set of Four 1.25" PLOSSL Lens for TELESCOPE, Brand New | eBay

[liphook]

Have you downloaded stellarium yet? This will tell you where things are in the night sky.

yes downloaded it, just trying to work it out now

[AWR]

are these the plossl that are recommended?

Set of Four 1.25" PLOSSL Lens for TELESCOPE, Brand New | eBay

I'm not sure about those, they're a bit cheap. I'd stick to recognised brands. Plossl is a design of eyepiece made by many companies (with varying degrees of success)

I like my Vixen plossl (£30-40 new) and would happily recommend them. I'm sure others will recommend brands too.

Andrew