New To Astronomy & Need Eyepiece Selection Help

[Ian65]

Hi,

I have my first Telescope a Meade 5000 80 ED Triplet APO & I need to purchase eyepieces, the trouble is I have asked several retailers & I have received totally different answers which has left me confused.

I am hoping to get some better advice from the wider Astronomical community.

I may upgrade the scope one day in years to come, but I assume eyepieces if not abused will last a lifetime & so what I purchase I intend to keep & not upgrade.

My limited knowledge leads me to believe Naglers are the best & I was going to get 2” versions until I discovered they are limited to just a few sizes. Also was going for a Powermate x 4 for amplification.

What I suppose I need from you guys & gals is a clear idea of what power I need for observing planets & deep sky objects suited to the scope I have & pass on items more suited to something with more aperture which I may need in future years after an upgrade but not now.

Due to the likely cost I need to purchase my most effective combinations & avoid unnecessary purchases.

After the eyepieces are purchased & I have saved up I will be getting some CCD equipment, but this will be months down the line.

Again my scope is an 80 ED Triplet f6 with a 2” Revelation Quartz Dielectric with a focal length of 480.

Looking forward to your replies

Best regards Ian

[Zathris]

I am more into imaging than visial but this is what I know about eyepieces. The max power to expect is 50x per inch of apature. So the most you should attempt is about 157x. If you are planning to get a barlow a 4x is most likely over doing it. A 25mm and a 6mm plus a 2x barlow will give you a range of 19.2x, 38.4x, 80x and 160x. With that range you will have a nice wide field view for large nebulas, a mid range for galaxies and planetary nebulas and high power for lunar/planets.

I agree that 2" is far better because of the eye relief. A 6mm 1 1/4 eye piece has a very small exit pupil and can be a pain to use, but the 2" will be much more pleasant to use. And yes Tele View makes great optics, the price is high but the quality is fabulous.

In addition you should consider a filter or two. If you live in a light polluted area a good Sky Glow filter is a must. Also a OIII or Narrow Band filter for emission nebulas will just blow you away. The Sky Glow (AKA LPR) filter passes the Hb, OIII, Ha and SII wave lengths and blocks the frequencies that are given off by Mercury vapor lights, Sodium vapor and Florescent lights. This will help almost any object under light polluted skies. The OIII filter is not too good for clusters and galaxes, but is awsome for emission and planetary nebulas.

Zathris....

[pizwiz]

Excellent Advice!
Let me just add a couple of thoughts:
If Nagler eyepieces are within your affordable range, then I would suggest the 2.5X Powermate for a Barlow lens. I would stay away from the higher powered Barlows for now.
Don't go crazy with accessories to begin with. Wait to find out what you really need after you have a little experience under your belt. You can spend an awful lot of money on Accessories and end up never using them. ( I think we all have a few laying in a drawer somewhere )
The conventional wisdom of 50X/inch Max magnification is a wise one. With an ED quality objective lens you will be able to push that number a bit, but ONLY on exceptional nights of excellent seeing conditions. Don't be surprised that on many nights you will only be able to use 25X or 30X. It is the Atmosphere that limits this, not your telescope's optics.
So experiment, try different combinations of eyepieces until you get the best view you can. Tha'ts the best you can do for that night.
Some nights are just not made for Planetary viewing, so go check out Star clucters or other objects.
Don't forget to have fun ! After all, It's a Hobby !!

Adolph

[Ian65]

Hello Zathris,

Thank you for your kind reply.

I was not aware of the 50x PI of A rule of thumb, this is very useful to know.

Is this equation used regardless of type of scope used ie: refractor, reflector etc....

I hear a lot spoken about eye relief & exit pupil but I have no idea what it means in real terms. Does it have something to do with comfort & less headaches & what is a good ER index to obtain whilst selecting an eyepiece.

You are correct, filters will come but the eyepieces need to be acquired first, these will be the main financial burden.

I am no fool though, I know I will only be in the grasp of secondhand kit.

Luckily I live on the fringes of Derbyshire, so by popping in the car on a 20-30 minutes drive I will end up in the middle of knowhere away from, street lights, houses etc...., general light pollution.

All the very best

Ian

[Ian65]

Hello Pizwiz,

Thanks for your words of wisdom too, most appreciated,

That is a startling statistic about the magnification limitations due to poor observing conditions.

You could end up with money tied up in eyepieces which seldom get used!

I agree 100% that experimentation would be the best route, but short of finding someone who is generous enough to loan me some Naglers to try out that would be impossible.

There is no way even buying second hand kit I could afford to experiment, I assume you would lose money if trying to sell eyepieces on if you aquire something that is just not right for you.

You have hit the nail on the head, I fully intend to enjoy myself, but @ present I need to make some informed eyepiece purchases.

As it stands I have the scope, the mount & tripod but I have never ever looked through a telescope!

So much of what has been tried to be explained to me I can't even comprehend, as I have no practical experiance to relate it too.

Anyhow, thanks a million for the tips.

Very best regards

Ian

[Zathris]

In theory yes 50x per inch is about max; however, SCT's, MAK's and Newt's tend to have less contrast due to the central obstruction of the secondary mirror so don't usually do as well.

Exit pupil is the circle of illumination coming from the eyepiece. So a small exit pupil means you must keep your eye very steady and any movement off of axis will cause the image to dim or disappear.

Eye relief is how far back from the eyepiece you move your eye and stay in the circle of illumination. If you ware glasses a long eye relief will be of great benefit.

While eyepieces are of a higher priority, don't poo poo the filters. I live in southern New Mexico and go to a VERY dark site. Even there the difference between say the Veil nebula with and without the OIII filter is amazing. What is does for you is not to brighten the nebula (it will actually dim it some), but it will increase the contrast between it and the sky making it stand out.

Zathris....

[pizwiz]

OK, I did not use a wise choice of words!
When I said experiment, I meant that you experiment with the yepieces you have decided to purchase.
Every time you go to observe, conditions will be different so that the same eyepiece combination you used last night may or may not work today.
Another thing I left out, which really should have come first, even before any advice on equipment is to try as hard as you can to locate an Astronomy Club near you.
These clubs have "Observing Nights" or "Star Parties".
Here you can try out all kinds of Telescopes and eyepieces first hand. As far as I know, every Amateur Astronomer would be happy to have you take a look through his Telescope and will gladly answer any questions you may have. You can learn more at one of these star parties in one hour than you can in a year of studying Books etc. There is nothing like getting your hands on the real thing. This is the best single piece of advice I can give anyone who is totally new to the Hobby.
You said you live in Derbyshire? I believe I have some friends out there. I'll try to contact them and see if we can't get you started.
There is one thing which I am not sure I should mention.
But I'll try anyway. Please take this only as the suggestion it is.
Once you start shopping around, you will find that the top of the line eyepieces like Naglers and Pentax etc. sell used for just about the same price as new with only minimal savings.
My question is: Do you really need these expensive eyepieces to get started. I see these eyepieces more as special purpose tools for certain observing conditions rather than for every day use. There are many other types of less expensive eyepieces that give great views in scopes like yours that don't cost a fortune.
It took me over 30 years of observing before I purchased my first super duper eyepiece. And then it was for the express purpose to push my Telescope to it's maximum magnification for planetary viewing. Under normal circumstances it is not much better than my regular Ploessl eyepieces, but the few times a year when conditions are excellent, it really makes a difference.
I really hope this isn't too confusing, but I am always anxious to get newcomers started right so they can enjoy the hobby and not get frustrated.

Adolph

[Ian65]

Hi Guy's,

I would just like to thank all of you who took the time & trouble to offer your advice.

It is greatly appreciated & is very helpful.

All the very best

Ian

[cpc1100scoper]

I like the Meade series 5000 SWA eyepieces..affordable... and have a couple of Pentax ep's 40 and 7 ..thos eare hard to beat at any price for my eyes.. Then again my friend has a 31 nagler and I like my pentax far better..its all in preference... all eyes are not alike...
Just my 2 cents worth..
Cheers
Dave

[Rick Keppler]

Originally Posted by Ian65

Hello Pizwiz,

Thanks for your words of wisdom too, most appreciated,

That is a startling statistic about the magnification limitations due to poor observing conditions.

You could end up with money tied up in eyepieces which seldom get used!

I agree 100% that experimentation would be the best route, but short of finding someone who is generous enough to loan me some Naglers to try out that would be impossible.

There is no way even buying second hand kit I could afford to experiment, I assume you would lose money if trying to sell eyepieces on if you aquire something that is just not right for you.

You have hit the nail on the head, I fully intend to enjoy myself, but @ present I need to make some informed eyepiece purchases.

As it stands I have the scope, the mount & tripod but I have never ever looked through a telescope!

So much of what has been tried to be explained to me I can't even comprehend, as I have no practical experiance to relate it too.

Anyhow, thanks a million for the tips.

Very best regards

Ian

pizwiz brought up some excellent points. With a 'small' in relative terms refractor, an 80mm f/6, I would be thinking more of widefield low power. Getting any sort of useful magnification will make the image incredibly dim with a very small exit pupil which can be very frustrating to find/see.
A 24mm Panoptic is a superb 1.25 inch eyepiece with clean optics, good eye relief and excellent light throughput. Team that up with the 2.5x 1.25 inch Powermate for moderate power viewing and I think you will really enjoy it. While 2 inch eyepieces are very nice, be aware that the 22mm and 17mm T4 Naglers, while excellent, are big and very heavy eyepieces. Adding a 2 inch powermate and diagonal to the mix and your telescope will probably become so unwieldy and out of balance that it will be difficult if not impossible to use.
You never mentioned your mount either. If it isn't a tracking mount, unless you are a masochist, you can pretty much forget high power observing as well. Trying to get something into the field and keep it there while looking for the exit pupil - ooof, that's torture.