choosing an EP family

[JJDOBBER79]

Hi all,
I am starting to think about building a high end EP collection. Slowly, of course to be kind to my wallet. After much research and reading reviews. I have decided on televues. I have carefully considered XW and LVW, I get the impression (from reviews) the xw will be less than perfect for a 12" dob. (which I plan to have for a long time) and the LVW has mixed reviews, most good but very rare to hear a bad review about TV's. Anyway, I have a couple of questions for those more knowledgeable.
1.) Would, for example, a 12mm nagler in a 2x televue barlow be equivalent performance to a 7mm nagler.
2.) What is the difference between a TV Barlow and a powermate.

My initial plan is to buy 2 EP and 2 barlows (assuming the answer to question 1 is yes)
The 2 eyepieces are 12mm nagler and 35mm panoptic. If I couple these with a 2x and a 2.5x I will effectively have a 35, 17.5, 12, 8.75, 6, 3 (not that i would use the 3). This sounds to me like a very good range. Probably could add something like a 24mm later. Am I on the right track with this.
If so, I would probably start with the 12mm nagler and the 2x because I have the low power end covered (not with quality but enough to get me by for now). Any thoughts on this would be aprecciated.
Also, am I likely to get large crisp views of the planets with the high power nagler 12mm with a 2x. I know it depends on the seeing but I had a cheaper 6mm plossl and I could get the planets big but they were always blurry. Unfortunately, I havent really looked through quality eyepieces due to there being no club round here so I have no idea what to expect.

[JJDOBBER79]

Ok, I see a problem with this. The 35mm panoptic is 2" and the 12mm nagler is 1.25. Can I get both of my barlows in 2" and use an adaptor to use the 1.25 EP in a 2" barlow? is there any reason why this cant work?

[AG Hybrid]

Ever looked through a 12mm Nagler t4? Worst eyepiece I have ever tried looking through. The blackouts are atrocious. Get the Nagler 13mm t6. Small, lighter, optically great.

Personally I would recommend the Delos 14mm. Ethos sharpness and correction with color rendition of a Pentax XW. Superb in a 12".

I don't recommend the 35MM Panoptic. That had blackouts too. Good eyepiece, but the exit pupil would be too large for a 12". Its 7mm. Unless your a teenager your eyes wont be able to take advantage of an exit pupil that size. If you don't want the Nagler 31mm go with the 27mm Panoptic. It has a 5.4mm exit pupil. Far more useful.

BTW. Pentax XW 10mm and less are just perfection in a 12". The 10mm may just be one of the finest eyepieces every designed and produced.

[JJDOBBER79]

So, you would recommend the xw 10 in a 12". with a 31mm nagler. with the 2x and the 2.5x that will give me 31, 15.5, 10, 7.75, 5, 2.5. That is also a good spread. Will the 2.5 be completely useless or ok on planets. Any thoughts on the barlow question. I am just wondering why people tend to have every size rather than a couple of them and a couple of barlows.

[AG Hybrid]

Hmm. That could work no doubt.

2.5mm is 600x mag. You may get to use that effectively once? Maybe twice a year?.

If you want to keep it in the family then 10mm Delos is also available. The 12mm Delos is an option as well. That will barlow to a 6mm. Which is still a bit high. The 14mm Delos barlows to a 7mm. That's 107x to 214x respectively. A very nice spread. I sometimes wonder if buying the 8mm Delos was really necessary for general observing due to the nice spread the 14mm barlowed gives.

To answer your earlier question on the difference between a Barlow lens and a powermate. A barlow and powermate both increase magnification. A barlow will increase the magnification depending on its distance from the eyepieces bottom lense. I.E the GSO 2" 2x barlow will increase magnification by 2x in its stock configuration. Screwing in the barlow LENS on the end of eyepieces like a ES 2" eyepiece it will increase magnification by 1.6x instead of 2x. Adding spacers can increase the magnification over 2x. A powermate from what I understand has a fixed magnification. A 2x powermate will increase magnification by 2x whether its 1mm away from the bottom lens to 1 meter away.

[glend]

I have settled on a collection focused on best value and performance and not just green writing on them, even though I have one Nagler I had to wait for it to be on sale overseas to meet my value criteria. There are many excellent EPs available these days, don't limit yourself to Televue.

[MattT]

It does help to know what you prefer in the Eye Relief stakes, long ER or don't care cause it doesn't matter. Do you wear glasses, do you view with glasses? I don't know if you have stated it already but what have you got now eyepiece wise? Does your dob have tracking? Do you have a Coma Corrector of some kind?
Matt

[JJDOBBER79]

Hi Matt,
no Glasses. I have a 12" lightbridge. The only eyepieces that I have are a 30mm superview, a qx meade 26mm. (a regular on the worst eyepieces ever lists) and the one pictured, no idea what it is, seems to perform quite well though. I like veiwing galaxies, nebula, PN and planets which I want to see huge and detailed if this is even possible. no tracking, no coma corrector. Glen, I definately have been considering the xw's and I dont want to limit to the EP's I have mentioned. I just want a good range of focal lengths to get me going. Adrian, I hadnt ever considered screwing the barlow lens directly onto an EP. I guess this would make them even more versatile.

[Camelopardalis]

Personally Jas, I feel you're proposing way too many eyepieces. While we may tend to accumulate them over the years, if you're going to take the plunge with premium eyepieces then do it one at a time and be targeted as to which focal lengths you buy.

If I'm honest, I rarely use more than 2, sometimes 3 eyepieces in a night, but I have a small collection because I have telescopes with (very) different focal lengths...from a 71mm f/6 refractor to a 280mm f/10 SCT. Even then, I've bought them semi-strategically so I can get most value out of the high value purchases. I'm also not a big fan of using a Barlow with bigger eyepieces because of the extra leverage! That doesn't mean they can't be used securely, just that I'm paranoid about the extra connection and having the precious glass fall to the ground :(

I'd agree with Adrian that the 13T6 Nagler is a great eyepiece, it almost has it all, nice wide view, pin sharp and it is compact and lightweight. But I'm not sure it's a wildly useful focal length if you're starting out with a new collection. I'd suggest a 9 or 10 mm, giving you 150-170x which is good for globular cluster, some planetary nebulae and planets themselves if the seeing ain't all that great.

You'd probably want something to give you higher magnification but I'd suggest trying the more useful focal length first, and if you get on OK with it you could get a shorter focal length of the same design for the nights of better seeing (if you don't see that as too frivolous of course). Or pick another design that is appropriate for the task. XW and Delos are great for planetary, but so are little orthos (at a fraction of the price) and beastly Ethoses :D (at double the price!)

Then there's the wide field view...the 31T5 Nagler is a fine eyepiece but at a fine price too :lol: the Explore Scientifiic 30mm 82 degree is within a hair of the Nagler and half the price. I know I'm not alone in here for lovin the views from that eyepiece ;)

[Camelopardalis]

Oh and when it comes to springing for the 100 degree beasts...try before you buy, unless that sort of cash is of no consequence to you :lol:

Another point with them is that with the wider apparent FOV you can get away with fewer of them because objects can be framed as much as you want...just because you have this huge apparent FOV to look at doesn't mean to say you've got to use it :D but you can frame some nice big objects with them for sure :thumbsup:

I guess my point is...you don't have to spend the earth to have your cake. And eat it. It can be done with a few carefully chosen pieces.

[glend]

When building a high end EP collection I believe time at the EP could be an important factor in determining what you want and need for the kind of astronomy your doing. Also, EP development is happening rapidly, just look at the choices in wide AFOV EPs that have emerged in the past year or so.
That 30mm Superview is a good start, it is well regarded and incredibly good value for money.

I'd suggest going to some Star Parties or events and having a look through a range of EPs in scope of similar size to yours. Given your location it might be worth considering coming along to the Star Party/Astro Camp at Lake Chaffey east of Tamworth commencing on the 24th of February through the 2nd of March (new moon weekend) (if that's feasible for you). Even if you can just get there for one night on the weekend there will be plenty of EPs to have a look through and I know there are a fair number of larger dobs coming along (at least one 12", a 14.5", three 16", as well as a larger CPC, various smaller goto refractors and newts. There will be a range of Televue EPs there, other high end EPs, as well as at least one Paracor, many barlows, and other goodies.

Finally, it might be worth talking to IIS member 'glenc' who is up your way (Casino I think), he has a 16" dob.

[Kunama]

I'm surprised that you have discounted the LVWs so easily, they are excellent eyepieces, at a very good price and the set are also all parfocal.
I've used mine in 200mm F4 Newt, 210mm f11.5 DK and refractors ranging from 60mm F5.9 to 150mm F10, they have performed extremely well in all scopes. They are sharp right across the field. They have a tiniest bit of colour on the very edge of the view and a slightly warmer tone than Pentax. They all have 20mm eye relief. All but the 42 can be used in either 1.25" or 2" visual backs or diagonals, the 42 is 2" only.
I haven't used Televues in years so can only really compare to Pentaxes.

I find that on any given night I will only use 3 eyepieces out of the full set, however, the actual eyepiece in use depends on the scope. The 3.5mm LVW is magical in the FS60 but useless in the µ-210. The 42mm is great in the Mewlon and pointless in the FS60. If you're going with the just the one scope 3 good eyepieces should keep one happy for years. I hate eyepieces that need your eye jammed into them so I always go for 15mm + ER.

[JJDOBBER79]

Thanks guys, now I dont know what to do. I had it all figured out at the start of this thread. Maybe I am reading too much into it. Now im thinking it doesnt really matter as long as I go for the high end EP's. They tend to hold their value pretty well so worst case scenario, if I buy something that doesnt work out, I can sell it, probably only lose $40-50 and try again. This is probably the main reason I wanted to go straight to the big guns rather that step up in increments. I would probably lose too much going that way. Anyway, going from what Ive currently got to Tvs or xw's i reckon its highly unlikely that I will be disappointed in whatever I buy.

[Camelopardalis]

Probably not...but it's diminishing returns beyond a certain point.

Keep it simple... have a think about your preferred targets, look up a few in Stellarium, Sky Safari or whatever astro prog you use and see what sort of field of view you need, don't forget to frame them nicely. Then buy one you think you'd get the most use from. No need to go crazy right off the bat. As has been mentioned, eyepieces can be a very personal thing... but resist the compulsion to buy in every focal length or perceive gaps in your choices, as you'll often not need or notice them in practice ;)

[MattT]

In another thread Don Pensack recommends 20 10 and 7 with a 2x Barlow. I'd add a 28mm to that for a sub f5 dob.
Get a 2" barlow for wide field 28mm eyepieces are 2" barrels.The 28 becomes a 14mm which is perfect in-between the 20mm and 10mm.
Has taken me years to work out what I like and what goes best with which scope. Still making mistakes :D
Matt

[Allan]

Jas, it's easy to get confused with a question like this, because everyone has different experiences and opinions they offer. All the top end eyepieces are very good and you won't make a bad decision with any of them. But if you have decided on TeleVue's then stick to your guns and buy them, they are the best IMO.

Powermates are a newer, better version of the Barlow. They have better coatings and don't increase the eye relief of the eye piece. A 2x in your 12" will be useful, but I hardly use mine because I like to use eyepieces straight up. I wouldn't suggest spending your money on 2 powermates or barlows, I don't think you would use them both enough to warrant the cost. Put the money toward another eyepiece.

Naglers are very nice, but for a few extra dollars you can get the Delos. Apart from the slightly smaller field of view, the Delos is a better eyepiece in every way.

On the other hand the perfect eyepiece for an un-driven Dob is the Ethos. Al Nagler's suggestion for the perfect eyepiece set is the 21, 13, 8 and 6 Ethos. I was going down that path until I bought a Delos to try and liked it so much I stuck with them for the shorter focal lengths.

IMO, if you are planning on spending Nagler type dollars, spend a little bit more and buy a set of Delos. Just another opinion to confuse you more. :D

[barx1963]

In my old 12" dob I used the following set. 24mm Panoptic, 13mm t6 Nagler, 7mm t6 Nagler.
Tried others such as a 6mm Delos and a 10mm Ethos. Easily the best combo was the 13 and the 24. At a 1500mm FL in the scope they gave 63x and 115x which is just about perfect. The 24mm Pan is nice and inexpensive and gives simply superb views, good eye relief at 15mm, pin sharp to the edge and lightweight. A 4.8mm exit pupil in that scope is pretty much ideal IMHO
The 1
13mm t6 Nag is pushing the power a little in a 12" f5 but if conditions are reasonable it gave good views with great contrast. Eye relief is a little tighter at 12mm but still OK.

Overall I spent many hours just using those 2 EPs with probably the 24 in te scope 80% of the time and the 13 most of the rest.

The 6mm Delos was really pushing the power and despite the eye relief it wasn't really comfortable to use with such a small exit pupil. 7mm Nag was similar without the added eye relief and while the 10mm Ethos was lovely conditions rarely warranted pushing to 150X

My recommendation is just get 2 at most 3 good eps. You can add others for other scopes or specialized tasks but observing is much more fun if you are not constantly changing EPs and concentrating on th view instead.

Malcolm

[brian nordstrom]

:) Takahashi sky90 , 3mm TV Radian , 5mm TV radian , 6mm TV Radian , 14mm TV Radian , 16mm Nagler T2 , and 27mm Panoptic .

;) 127mm Istar f8 frak , 8mm TV Radian , 10mm TV Radian , 12mm TV Radian , 14mm TV Radian , 19 , 22 and 24mm Panoptic's .

:D C9.25 XLT , 9mm Nagler T2 , 13mm Nagler T1 , 17mm Nagler T4 , 18mm TV Radian , 20mm Nagler T1 , 31mm Celestron Axium LX and 40mm TMB orthoscopic .

Not necessarily in this order , but it works for me .. LOL . I have the SKY90 and 14mm TV Radian on the moon at the moment giving 35x and passers by are spell bound ...

Brian.

[JJDOBBER79]

Hi, Malcolm.
So, if I get the 24 pan and the 17 nag, I can add a 2.5X barlow later and that will effectively give me 24, 13, 9.6, 5.2. Thats looking like a pretty good combo to me. I understand that 5.2 will not get used much but surely if seeing permits planets would be quite large in the eyepiece. My only concern is at the low power end. Is the fov in the 24 pan ok for galaxies or do I need something like a 35/40. I guess it all depends on the target right? M31 for example is quite different to most other smaller galaxies. In any case I can always add something later at the low end. So from what adrian was saying earlier in the thread, the 35 pan is not ideal due to exit pupil but the 24 is far more suited to a 12"? Also, like you said, probably one of the more inexpensive combos I have considered so far. Thanks for your help.

Oh, and Brian, you look like your living the dream!

[JJDOBBER79]

Any thoughts on the 17.3 delos in a 12" scope. They seem to be significantly cheaper than the nagler and the barrel size is the same as the panoptic. This is a bit more convenient. Is there any reason why I should go for the 17 nagler over the 17.3 delos?

[glend]

I believe you need something like a 2" 30mm, my 30mm is the EP I always start out with on my pushto dob and when you barlow it you have a 15mm equivalent. I believe Televue's eyepiece paper, that; s sent out with new EPs, suggests field stop selection. If you go by Al Nagler's advice there he suggests a field stop of 40mm which equates on their spec list to a 31 Nagler 5 or a 35 Panoptic. The 31 Nagler 5 will give you a wider field of view than the Panoptic.

[JJDOBBER79]

I have just seen ES 100 degree 20mm at astropetes for $399:eyepop:
Also, I have just read a post on deep sky forum from someone claiming that they are almost as good as the ethos. There is certainly a massive price difference. Does anyone have the ES and use it with a 12" dob? I figure I should maybe start with this and barlow it up to 10mm. Maybe ok for galaxies at 20mm given the extreme FOV????

[Allan]

Picking which focal lengths to get is not too hard. At the low power end it's good to have something that approaches the largest exit pupil you can use in your scope. That will be an eyepiece that is good for cruising the sky and checking out larger objects. I can see M31, M32 and M110 in the same FOV in my 31 Nagler. Although if your site is a bit light polluted you might not use the 31 so much, but it is a magic eyepiece from a dark location. I probably use my 21 Ethos ten times more than my 31 Nagler in my yard, which is a bit light affected.

The high power end is limited by the atmosphere. I have found over time the 6mm is about the shortest focal length I like to use in my 12". You could always get a 12 and Barlow that.

So between low and high power you just fill in the gaps with logical steps. Just be aware that as the focal lengths get shorter, you need to have smaller gaps between focal lengths as the magnification rises rapidly.

The 24 Pan is a nice eyepiece, but seeing as you ask, it won't see much use on galaxies, except for the big show piece ones. Most galaxies are quite small. My most use eyepiece is the 10 Delos for galaxies as it hits a sweet spot for magnification and FOV.

The only thing the 17 Nagler does better than the Delos is a larger FOV. The Delos has the flattest FOV, best transmission, best colour rendition, better eye relief, is lighter. Having said that, I really like the 17 Nagler as it's a great eyepiece, but you are comparing it to the best widefield eyepiece you can buy. So IMO there is not much reason to buy the 17 Nagler when you can spend less money buying the 17.3 Delos and end up with a better eyepiece.

So a setup with a 31 Nagler then 17, 12 and 8 Delos is one option that ticks a lot of boxes. But you can kick this can around all day and keep coming up with different ideas. That's half the fun.

[Allan]

People who get the ES seem very happy with them. Almost as good as Ethos but a lot cheaper. The only negative thing I have read is the eye relief is quite tight in comparison to Ethos. But the FOV in the 20 is so wide it could work as your low power eyepiece.

I would have second thoughts about barlowing it though. These are big and heavy eyepieces.

[AstralTraveller]

Keep an eye on the classifieds. You just missed a 20mm ES for $270. I bought all my premium wide-field eps though the classifieds (and deep bows to ep recyclers).

FWIW I suggest fewer good eps and I'm not too fussed on barlows. Maybe that's just a hangovers from too many cheap barlows. About you low power ep, if your pupil can open to, say, 6mm then the lowest useable mag = 300/6 = 50x. Assuming your 12" is f/5 then your widest ep would be a 30mm (or31). The 31 Nagler was beyond my budget so I wound up with a WO 28mm UWAN. I haven't done a side by side comparison with a 26 or 31 Nagler but it looks dang fine to me. It certainly doesn't lose much to my excellent 20mm Type 2. I spaced wide-field my eps in the ratio 3:2, so 28-20-13-9. That covers all bases. Then I have UO orthos for the planets.

[JJDOBBER79]

I really like the idea of the 100 degree ES. I think I will get one of those and for higher power I reckon a delos (mainly because of price) either 14 or 12 and a 2x TV barlow. (and maybe a 31 nagler down the track when my wallet recovers)
Allan, I forgot about the the extreme weight and size of the ES, wont be barlowing this. Given the extra wide FOV, does it mean that the ES would be more useful for a broader range of targets? David, I definately will keep an eye on the classifieds. I think everybody on this forum treat these kind of high end EP's like they are children so will be happy to buy off here.

[MattT]

Those were my ES 100º….maybe a bit too cheap…who cares... I don't. They were really terrific in my f8 6" and f9 100ED refractors, but not so good in my f12 6" refractor, don't know why. I have had them in my f4.8 Newt and didn't like them one bit…talk about coma city. So if you get the 100's you are going to have to get a coma corrector too, at least I had too, and that is a lot of tubes hanging out the focuser…a lot. Give me 68º eyepieces any day. Not so bad in the Newt without the CC perfect with the CC (coma corrector) and perfect in any of my refractors 70mm f7, 90mm f11, 100mm f9, 150mm f12, and not forgetting 50mm f12 :) What a little cutie it is.
If you haven't done so check out the Cloudy Nights eyepiece section…it's a mine of information…..
Shees where is Suzy when you need her, now her threads are really worth reading :thumbsup:
Matt

[JJDOBBER79]

so, you wouldnt recommend the 100's in a 12" dob?
Is anyone out there using this combo because the problem with them being so big means that I cant barlow and I cant coma correct.

[jamespierce]

My 2 cents.

If possible buy from the same series (you get constant field stop, colour and handling etc)... So I've gone with all Naglers, but you could go Ethos or ES etc...

Forget the barlows ... I have one, never use it ... I don't know a serious observer who uses one with any regularity... More glass, more flare, more weight and alignment issues.

As for what focal lengths to get...

Whatever gives you a 5-6mm exit pupil for your scope. Something around the 1.8-2mm range (this is basically the sweet spot). Something around the 1mm mark, and down the track, perhaps something pushing 0.5mm for very good nights on the planets...

In my 16" F4 I have 31,20,13,9,7 Nag ... The 20 and 13 see the most action, then then 9, followed by the 31 and 7. I also have a 5mm Tak LE for very very good nights - very sharp EP.

This calculator is very helpful - http://www.davidpaulgreen.com/tec.html

[Allan]

My coma corrector is an integrated part of my focuser and I just forget it's there, and I never think about coma. Having a big 100 degree eyepiece in a Paracorr is a big setup to have in your focuser, but I see plenty of people use that setup. If you don't want to do it that way you will have to get used to the coma.

I found my Ethos without the Paracorr is still ok, it's there but not too objectionable, they may be better corrected for coma than the ES. All these little improvements explain why Ethos are more expensive.

You won't notice much coma at all in the Delos because of the narrower FOV. You can get away without a Paracorr using them.

[MattT]

Allan are you binoing with the SIPS? You don't bottom out and hit the lens?
The ES 20mm weighed 990grams from memory and you can put a Coma corrector in the focuser they aren't that big…I just prefer the 68º eyepieces. 82º I tried but never really liked but the 68's hit the spot for me…and lots of others too. Can you try a 20 ES 100º and send it back and get something else if you don't like it? Worth asking.
The 20mm ES 68º I use in the Newt is Coma free to about 80% out. I'm a refractor user mostly and the ES 68's are all pin point sharp to 98% out. The last 2% isn't worth the hundreds of dollars extra to get Panoptics.
If you buy used most likely you can sell for much the same price if you decide you don't like it.

[Allan]

Hi Matt. No I am not bino viewing with the SIPS in. I replaced the Allen head screws in the Feathertouch with thumbscrews. So when I change from mono to bino I loosen the screws and remove the lens section, then refit the focuser. It takes no more than 20 seconds to change modes.

[JJDOBBER79]

Ok, I've made a final decision.

100 degree ES 20mm, not barlowed
14mm Delos
Xw10
2x TV Barlow
This will give me 20, 14, 10, 7, 5

The 14 Delos will come first as I feel it will be most useful. If I don't like any of these I will resell and get something else in the same focal length. Thanks for everyone's help with this. Big decision. I'm sure the collection will not stop there. :P

[Camelopardalis]

I think in a 12" Dob you'll use the 20 a lot, the others not so much :lol:

I can understand your compulsion to want to experiment, we've all been there :D but don't rush to buy the Barlow... you'll prolly find out (like the rest of us) that it's a lot of fumbling in the dark with expensive optics :sadeyes:

[JJDOBBER79]

Yeah maybe. The Barlow will probably be last. It's just to push the power a bit on good nights. I'm hoping that quality like Delos and xw will handle this in good seeing.