Advice on beginner's eye piece/barlow ? lol

[tingting44]

hey folks i am on the hunt for a decent new ep, i do not really know what i am looking for or what to buy lol i was going to get an illuminated recticle ep to help with aligning but im not too sure now lol,

idealy i would like an ep to improve my views of planets, but saying that i cant see mars any more from my garden view as by the time it gets dark it has all ready gone past my house roof blocking my view, i did see it about a month ago, but did not really have no WOW factor to it, was viewing with my standard ep's that came with my skywatcher 130p which are 25mm wide, 10mm and x2 barlow.

how ever when i saw saturn that definately had the WOW factor and i was giggling like a little kid lol, but that keeps getting closer and closer to becomming obstructed by my house roof like mars has done now, maybe a few more weeks and i wont be able to see it i think so not sure to get an ep for planetary as the 2 planets i can see from my garden will be no more

that just leaves me with viewing stars and nebula's if i ever find a nebula that is lol i really need some help as im dying to buy my 1st ep but just dont know what to get, any suggestions/links/help/your own experiance on ep's would be most welcome, thank you guys and gals

edit, im not worried about buying 2nd hand if the price is right loool, only thing is i cant see the for sale section here where i do not have enough posts

[JamesF]

Jupiter will be along fairly soon. I'd wait for that, see what you think it looks like in the barlowed 10mm eyepiece and make your decision from there. Having some decent high magnification eyepieces is really nice when you want them, but in my case at least, the ones I have in the 32mm to 15mm range see a lot more use. Whilst there are seven other planets, two are too far away to be in any way rewarding with your scope, if they even are with anyone's. One is hardly ever visible because it's so close to the sun and one isn't that exciting visually. Of the remaining three, two are pretty much done with in their current apparition. On the other hand you have all the Messier objects and probably a few more things besides that you don't need a high magnification eyepiece for. If you did start finding a few of those your view of what you might want next could well change.

James

[tingting44]

hey James

ohh jupiter! that is exciting! the biggest planet in our system, id love to be able to see the big red dot yeah i hear you, i would love a high power ep but im not too sure how good it would serve me? as at the moment i get quite a bit of shake just with my 10mm ep needless to say it does not help being next to the main train station rail way lol and dual carriage way! GOSH! lol

i can not wait to start on the hunt for messier's, the messier was put together for objects we are able to see right? or something like that i cant remember that clear now... are ngc's and ic's easy to see?

i think im just wanting to buy my 1st ep as i have not bought one yet but to buy one just for the sake of buying one would be silly, and i know your right i should really wait and try and see some messiers 1st lol

[tingting44]

i had to put this in for any noobs!!! WOW i can not wait for my next clear night!!!!!!!!! i know vega and arctucus down to a tee aswel! as i use them to align and have a great view of inbetween where M13 is :)

edit, oopps forgot to put link lol

http://www.themcdonalds.net/richard/index.php?title=Finding_M13

[JamesF]

The red spot isn't always visible on Jupiter, partly because it can be on the other side of the planet, but also because sometimes it just disappears. There's a lot of surface detail there though so even if the GRS isn't visible it's usually good to view at decent magnification.

The Messier list is a list of 110 objects compiled by Charles Messier. The was into hunting comets and there's a story that the list was his "list of things we can see that aren't comets", but I don't believe that's true. However it works well as a list of objects that are relatively easily visible from the northern hemisphere with small-ish telescopes (he had access to quite reasonable size scopes for the time, but mirror-making technology, for instance, couldn't produce anything as near as good as is possible now). As Messier was French and IIRC spent some time working in Italy, a few (half a dozen or so depending on your latitude) of those objects are "challenging" to view from the UK, but the rest are quite feasible. Some are visible with the naked eye from a dark site and some you really have to work for, but it's an excellent place to start. I believe all the Messier objects have an NGC designation (not entirely sure), but as they're better known by their Messier number you usually see them identified that way. The other side of that coin is that objects known by their NGC number are ones Messier probably couldn't see and are therefore more tricky to find with a small scope.

If you're suffering from vibration with your scope you may find there are ways to make it more steady. I'm not familiar with the AZ GOTO tripod, but it's often said that filling tripod legs with sand, or suspending a few kilos from the head of a tripod can help to reduce vibration.

James

[tingting44]

thanks james, even if i do not see the GRS i will be buzzing as i would have spotted my 3rd planet

very nice info on messier's also!! great to know they should be quite easy to find, my scope/synscan goto mount has got the messier catalogue built into so in theory i should just have to say click on M13 and it will take me to it? im in 2 minds how accurate this will be for messier;s i really can not wait to try this out, been dying to get out for weeks now this sucks! with all the cloud,

lol think i might leave the NGC's alone for the time being, atleast till i get familiar with M's :D

great advice with helping with my vibration, thanks their, i might see if my tripod leg bottoms will pop off and shove some sharp sand in them and try and weigh it down with some things from round the house, thanks for all your help james, most appreciated buddy!

edit, is turn left at orion all it is cracked up to be? ive found it for £18 on the bay?

[JamesF]

If you get the scope nicely aligned to start with then it should find you the Messier objects fairly easily. I think it's worth matching up star patterns with, say, Stellarium as well though, so you can confirm you're seeing what you think you're seeing. Learning to star hop a bit will probably help if it's a little out as well.

As regards weights, assuming you can find some method of attaching it, an old plastic drinks bottled filled with water or wet sand can work a treat for adding a few kilos.

I've not seen the new Turn Left At Orion, but I found my older one a great help, not just as regards what I could see, but in actually explaining how things work. In some respects I think the new edition may be better as I gather it takes into account the advances made in the market for affordable reflectors over the last ten years.

James

[Spec-Chum]

edit, is turn left at orion all it is cracked up to be? ive found it for £18 on the bay?

Oh yes!

Also, I got mine from here : http://www.bookdepository.co.uk/Turn-Left-at-Orion-Guy-Consolmagno/9780521153973

Brand new, under 16 quid and delivered in 3 days...

[Capricorn]

Messier objects were a list of £fuzzy" things that were not stars, but most importantly to Messier were not comets.

Since he was in Paris and that area then all are visible in our northern latitudes.

Since Messier had a relatively small scope you should be able to see them all although he had somewhat less light pollution then we have.

NGC's are another catalogue, it includes Messiers but being bigger many are therefore fainter the the Messiers.

To see the red spot on Jupiter I think you will need more magnification then your scope will supply. JUpiter is a long way away and the red spot is a small bit on Jupiter.

Eyepieces: Depending on the budget per eyepiece then:

Vixen Plossl's @ £30 a piece.

TMP Planetary clones @ £39 a piece

BST's (Starguider now) @ £47

Lacerta Planetary's @ £47

Celestron X-Cel's @ £69

The plossl will have poor eye relief when at 8mm or less.

The BST's have a good reputation and occasionally one comes up for sale.

The spread is reasonable and 3 or 4 would make a good set to be usable for most occasions and scopes.

Equally do what quite a few have done and build up the whole set (6).

I suspect that the 5mm in your scope would show Saturn much clearer then the 10mm+barlow combination.

The planetary's tend to be available in shorter focal lengths but then you could be exceeding the scope's capabilities.

[tingting44]

If you get the scope nicely aligned to start with then it should find you the Messier objects fairly easily. I think it's worth matching up star patterns with, say, Stellarium as well though, so you can confirm you're seeing what you think you're seeing. Learning to star hop a bit will probably help if it's a little out as well.

As regards weights, assuming you can find some method of attaching it, an old plastic drinks bottled filled with water or wet sand can work a treat for adding a few kilos.

I've not seen the new Turn Left At Orion, but I found my older one a great help, not just as regards what I could see, but in actually explaining how things work. In some respects I think the new edition may be better as I gather it takes into account the advances made in the market for affordable reflectors over the last ten years.

James

nice, i think thats where the illuminated recticle will pay for itself then getting the scope nicely aligned mhhh i wish i had soo much more money lol yeah i allways use stellarium hooked up to the scope to get my field of view recticile on the laptop where my scope is pointing i have done a bit of star hopping but through the ep really, i dont really use the finder scope really?

great tip on the plastic bottles mate!! i could then just put the bottle in a plastic bag and tie on to somewhere around my ep tray on the mount, thanks bud!!

sounds good on turn left at orion everyone seems to rate that! have to get it next week for sure i think

Oh yes!

Also, I got mine from here : http://www.bookdepos...o/9780521153973

Brand new, under 16 quid and delivered in 3 days...

great stuff buddy!!! i am ordering this before anything i think tomorrow!! thanks for the link will get it from there

Messier objects were a list of £fuzzy" things that were not stars, but most importantly to Messier were not comets.

Since he was in Paris and that area then all are visible in our northern latitudes.

Since Messier had a relatively small scope you should be able to see them all although he had somewhat less light pollution then we have.

NGC's are another catalogue, it includes Messiers but being bigger many are therefore fainter the the Messiers.

To see the red spot on Jupiter I think you will need more magnification then your scope will supply. JUpiter is a long way away and the red spot is a small bit on Jupiter.

Eyepieces: Depending on the budget per eyepiece then:

Vixen Plossl's @ £30 a piece.

TMP Planetary clones @ £39 a piece

BST's (Starguider now) @ £47

Lacerta Planetary's @ £47

Celestron X-Cel's @ £69

The plossl will have poor eye relief when at 8mm or less.

The BST's have a good reputation and occasionally one comes up for sale.

The spread is reasonable and 3 or 4 would make a good set to be usable for most occasions and scopes.

Equally do what quite a few have done and build up the whole set (6).

I suspect that the 5mm in your scope would show Saturn much clearer then the 10mm+barlow combination.

The planetary's tend to be available in shorter focal lengths but then you could be exceeding the scope's capabilities.

thanks for the ep info there buddy seeing as my illuminated recticile is £40 it seems rather expensive

i see everyone talking about eye relief, please do not mock me but what is eye relief? i will try and find some BST's i think i get ya so a nice addition might be a 5mm BST and build up a set over time

[JamesF]

i see everyone talking about eye relief, please do not mock me but what is eye relief?

The "eye relief" is how far your eye needs to be from the eyepiece to see a properly-focused image. Some high magnification (short focal length) eyepieces require your eye to be very close (within three or four millimetres) of the eyepiece which is impractical if you were glasses and just uncomfortable for some people. Expensive eyepiece designs may be better in that respect.

James

James

[tingting44]

The "eye relief" is how far your eye needs to be from the eyepiece to see a properly-focused image. Some high magnification (short focal length) eyepieces require your eye to be very close (within three or four millimetres) of the eyepiece which is impractical if you were glasses and just uncomfortable for some people. Expensive eyepiece designs may be better in that respect.

James

James

mhh so my standard ep's that came with my scope, they come with a round rubber thing that flips up so you eye has to be pushed against that right? so they would be poor eye relief?

[JamesF]

Since Messier had a relatively small scope you should be able to see them all although he had somewhat less light pollution then we have.

Messier actually had access to some quite reasonable size telescopes by modern amateur standards. At least around the 6" to 8" size. His disadvantage was that the mirrors were nothing like as good as modern ones because they were made of a polished alloy of copper and tin rather than glass. Herschel (very much a contemporary of Messier) was in the same boat, but he was making his mirrors much larger.

James

[JamesF]

mhh so my standard ep's that came with my scope, they come with a round rubber thing that flips up so you eye has to be pushed against that right? so they would be poor eye relief?

There are some eyepieces with eyecups intended to position your eye at the optimum viewing position. I think with cheaper eyepieces the eyecups are more about keeping out some of the stray light though. I'm fairly sure I don't get that close to the eyecups on the eyepieces I use that have them (my really short focal length eyepieces are Baader Genuine Orthoscopics, which don't have eyecups at all).

James

[tingting44]

how do you cope with stray light getting in then james with your baader ones then with no eye cups? so ep's with eye cups are generally cheapo ones like my standard ones that came with my scope? isnt it harder trying to hover your eye over the ep with no eye cup to get the correct distance?

wow just see your sig of your equipment!!!! WOW!!!

edit, and wow on your objects you have seen!!! how long u been in this hobby for buddy?

edit, just updated my sig!! lol

[JamesF]

how do you cope with stray light getting in then james with your baader ones then with no eye cups? so ep's with eye cups are generally cheapo ones like my standard ones that came with my scope? isnt it harder trying to hover your eye over the ep with no eye cup to get the correct distance?

wow just see your sig of your equipment!!!! WOW!!!

edit, and wow on your objects you have seen!!! how long u been in this hobby for buddy?

Had a nasty plastic build-it-yourself telescope before I reached my teens, but I've only been "doing it properly" for a couple of years. I do however have a few advantages in that I live somewhere with very dark skies and almost no light pollution (the nearest street lighting must be at least two miles away) and I work for myself so the boss doesn't throw a strop at me if I roll into work late after a decent night out with the scope. I might also have two children that I'm encouraging to be interested in astronomy so we can gang up on my wife when I, err, we want new toys, but I'll deny any such scurrilous rumour most strongly should it get around.

James

[tingting44]

Had a nasty plastic build-it-yourself telescope before I reached my teens, but I've only been "doing it properly" for a couple of years. I do however have a few advantages in that I live somewhere with very dark skies and almost no light pollution (the nearest street lighting must be at least two miles away) and I work for myself so the boss doesn't throw a strop at me if I roll into work late after a decent night out with the scope. I might also have two children that I'm encouraging to be interested in astronomy so we can gang up on my wife when I, err, we want new toys, but I'll deny any such scurrilous rumour most strongly should it get around.

James

sounds like you got the ideal life!! can i come live with you loooool :D i have one big nasty street lamp hanging over my garden from the dual carriage way i need to get on to the city council about it as its hard to even sleep where its soo bright

is this a nice lens? with no eye cup, it seems difficult to get your eye correct viewing distance with no eye cup lol but thats all ive used (ep with eye cup) so thats probably why im use to the cheap ones lol

http://www.firstligh...rthoscopic.html

[JamesF]

so ep's with eye cups are generally cheapo ones like my standard ones that came with my scope? isnt it harder trying to hover your eye over the ep with no eye cup to get the correct distance?

Forgot to answer these.

It's not that cheap eyepieces come with eye cups, but that more expensive eyepieces tend to come with better-designed eye cups (when they have them) I think. The BGOs take a bit of getting used to, but I actually find them quite easy now. It's possible they don't have eye cups because the eye relief is so tight and the cups would be a distraction. I know some people don't like them because with the shorter focal lengths their eyelashes touch the top of the eyepiece and they find it uncomfortable.

James

[tingting44]

thanks, i suppose im only going to know if i get on with the different ep's is by trial and error i guess, i might order the 5mm baader ep and see if its for me. realllly tired now and need to get some sleep, great talking with you all tonight! hope you all have a nice evening and speak tomorrow, night

martin

[JamesF]

sounds like you got the ideal life!! can i come live with you

I keep telling people that it's not all wonderful. There's no delivery Indian/Chinese/Pizza, for instance. There are Chinese and Indian take-aways, but they're three miles away. There's no pub or shop within staggering distance. Satnav would put you in a farmer's field four or five hundred metres away. Tesco will deliver, but no other supermarkets do. There's no mains gas and no mains sewerage. If it snows heavily then the only way to move for several days may be by tractor. Internet access is poor and there's no public transport. I love it, but it would give some people the screaming ab-dabs.

James

[tingting44]

morning aww james that sounds even better to me lol i hate living in the city mate a real slice of heaven you got there i tell you

[tingting44]

WOW! so this ep has an awsome eye reflief right? and great for viewing planets, would the 3mm be much good for my scope?

http://www.firstligh...l-eyepiece.html

[Qualia]

Great advice and conversation going on in this thread. Big thumbs up to Tingting for setting it up and another big thumbs up to James for going over some very informative reads. Thank you to both of you.

Robin, who's a member of SGL, has set up a great thread here. I found it most useful when trying to get my head around the world of EPs.

Other than that, with fear of repeating what has already been said, I've found the following to be useful general rules of thumb when trying to decide on EPs:

Magnification = F/f (focal length of OTA divided by focal length of eyepiece), for example: 1000mm / 25mm = 40 magnification.

So in this case, this will make the object appear 40x closer. A general rule of thumb is that due to less than excellent seeing conditions, it will be the rare occasion that you will be able to use more than 200x. It is also worth bearing in mind that the light from stars, planets, nebulae and clusters is on the whole fixed, so when you increase magnification that given light is spread out over a greater area of your retina which gives the affect of an image dimming. Thus, if the image is already dim and you wack up the magnification, the object starts vanishing. So, again, a general rule of thumb could be to use high magnification for planets and moon if conditions allow and low magnification for galaxies, globular clusters and star hopping.

EP's True Field of View (True FOV) = EP's afov/Mag (EPs Apparent Field of View divided by magnification), for example: 60º afov / 40 = 1.5º of True Field of View.

The True FOV offers you the angular width of the patch of sky you are looking at and because True FOV is often less than one degree, the value is given in arc minutes. There are 60 arc minutes in one degree. So, 1.5 degrees x 60 arcmin per degree equals 90 arc minutes as the True FOV of the 25mm eyepiece. A 5mm giving a True FOV of 0.3º means that the 5mm eyepiece provides a 18 arcmin field. As a rough rule of thumb the full moon offers you a width of about 0.5º, or 30 arc minutes.

Exit Pupil = a/mag (aperture/magnification), for example: 100mm divided by 40 = 25mm.

So here we could say that the exit pupil will offer an image of light at 25mm in diameter but the story hasn't quite finished. Firstly, that image of light will generally occupy only a small portion of the field of view (other than looking at the moon and sun, I imagine this will always be the case) and secondly, the actual size of the object will be greatly reduced depending on how far away it is. So why bother with exit pupil? Well, it is useful to have the calculation to judge how bright an image could be. The more the EP's exit pupil fills your own pupil with light, the more you will see a brighter object. As you increase your magnification the exit pupil gets smaller and as we have seen above, the image dims. It is here you'll find the reason why folk like and recommend greater apperture. A bigger scope not only helps make an image brighter but perhaps more importantly, it allows you to increase your magnification without the image dimming too much.

With that under your belt, I use the general observations, but be aware that there are other kinds of recommendations:

Low Power Workhorse: between 25 to 50 magnification.

Low Medium Power: between 55 to 85 magnification.

High Medium Power: between 100 to 125 magnification.

High Power: between 140 to 200 magnification.

Final point. I figure it is best to purchase EPs as and when you feel they are needed rather than buy a complete introductory set. Excellent beginner to intermediate EPs appear to be BSTs, Hyperions and X-Cel LXs, all of which come highly recommended here at SGL. On a personal note, I have found that around 140x to 150x is the sweet spot for planet viewing and for fainter objects and star-hopping between 40x to 55x, although come Autumn I will purchase an even lower magnification EP.

Hope this scramble and mess has helped to some extent?

[tingting44]

WOW! thanks qaulia for that very detailed message my friend!!! going to read over it a couple times to get my head around things, thank you so much, ive nearly bought so many ep's this morning, but think im just going to get some more experiance then buy what i actually need rather then what i want or looks cool lol

[Naemeth]

WOW! thanks qaulia for that very detailed message my friend!!! going to read over it a couple times to get my head around things, thank you so much, ive nearly bought so many ep's this morning, but think im just going to get some more experiance then buy what i actually need rather then what i want or looks cool lol

In addition to that, have a look at these:

http://www.skysthelimit.org.uk/telescope%20eyepieces.html

Look at the 58 Degree "TMB Design" EPs, they are very good for starters at £36 each, I have the 4mm and it's brilliant, gives me 162.5x on my scope (and will on yours too ).