televue choice for fast scope?

[Orange Haze]

Evening all.

I am on the verge of getting my second scope, a skyliner 250px Dob. Can't wait to get the beast back home, but I am aware that given its fast speed of f4.7, it will be hard on eyepieces.

The televue range feature high in peoples estimations and as I have a bit of Xmas money to add to my pot, I was hoping for some guidance. Looking at the televue range, I am a bit confused as to whether I should be looking at a plossil, a nagler or perhaps more likely a Radian??

Any experience you folks with fast scopes can share here would be great. Thanks!

[ronin]

The plossls are said to go to f/4 and except for the shorter end should be good, they stop at 8mm.

I believe that Radians were ceased and the replaccment is the Delos,

Naglers are certainly a possibility.

Comes to what do you want, and how much the budget is. Plossl's being less cost mean you get more, sort of 1 Delos or 2 plossl's etc.

[John]

Sharp to the edge fields of view with fast scopes is very much Tele Vue's forte and they are all (each one !) tested to work well down to F/4.

If you go for an ultra wide field like the Nagler you may well see some coma in stars towards the outer parts of the field but that will be the scope rather than the eyepiece.

The new Tele Vue Delos range seem to be really excellent offering both a wide field of view and comfortable eye relief.

I guess the range you go for will depend on your budget though ?

[swamp thing]

The beauty of televue eyepieces is they work superbly in any scope on any object.

Whatever speed your scope, and irrespective of what you look at a televue eyepiece will perform extremely well indeed.

[Orange Haze]

Thanks ronin. The radians are still on telescopehouse's site, although maybe its out of date.

Wanted an eyepiece in the 6mm range as this will allow me to test the scope close up on the moon.

Budget would allow me 1 delos or several plossls.

[Orange Haze]

Wow, thanks Steve and John as well. You seem to support the fact that televue are top notch. Maybe naive of me, but id prefer to spend bigger bucks in the shorter range and probably rely on the supplied 10mm and 25mm along with my 15mm vixen pieces to start with.

[BillP]

Lee,

Yup...an f/4.7 will be hard, so expect to see off-axis coma with any eyepiece, including TeleVue as coma is not corrected by the eyepiece.  So when you use the TV eyepiece it will not generate any astigmatism, etc.  To get rid of the coma you really need a coma corrector like the Paracor.

However, 15mm and shorter and generally coma is minimal at these higher magnifications.  So in my 10" f/4.7, coma is seen in outer 50% of the 24mm Panoptic as example when no paracorr is used.  Put the paracorr in and all the coma goes away.

If you are looking for a shorter focal length eyepiece, for planetary or high power, then I personally use a 6mm or 7mm most often in my XT10.  So a 7mm XW or a 6mm Delos would be grand for the scope.  Very comfortable with long eye relief, good adjustable eye guards on both, both very sharp and high contrast.  Also both expensive unfortunately.  If you want a little lower magnification, then a 10mm XW or a 10mm Delos (£251) or 11mm Nagler T6 if you are into the 82 degree stuff.  A really nice trio of TV eyepieces for this scope would be: 27 Pan (£295 / 1.5deg TFOV) or 26 Nagler (£429 / 1.7deg TFOV), 11T6 (£225), 7T6 (£259), then a 2x Barlow to get to 5.5mm and 3.5mm.  These 3 and barlow should serve 99% of observing needs in that scope, and the coma will probably be not too bad in the 27 Pan so might not need a Paracorr.

[Orange Haze]

Bill, thank you so much, fantastic to get such great advice. Does the use of the Barlow in your opinion reduce the quality of the view? I assumed my Tal x2 wouldn't exactly complement a quality eyepiece.

[bingevader]

If it's TV you are after, then you've come to the right place! We've numerous TV enthusiasts who'll be delighted to tell you how fabulous they are. But they do come at a hefty price. If they're within budget then, by all means, buy the best. If not, you might also like to consider the Explore Scientific 82^o range which have received very favourable reviews in the larger faster 'scopes. If it's plossls you are after though, the TV plossls are very good indeed.

Cheers

[Orange Haze]

Thanks Vader. Always found SGL the best source for reliable info. Appreciate the tip about the explore 82!

Cheers!

[Moonshane]

do consider my comments here about quality differences, especially p3 http://stargazerslounge.com/topic/166265-cheap-vs-expensive/  and also http://stargazerslounge.com/topic/188794-eyepiece-groups/

hope they help.

[Qualia]

I feel that although initially expensive, in the long term, premium eyepieces like those from Tele Vue will probably turn out to be the cheaper option and are never going to be a waste of money.

Many astronomers - myself included - follow quite a predictable path when it comes to buying EPs. We generally start out buying new and cheapish stuff but soon arrives a day when we want to upgrade or check out one of these premium eyepieces and so we find ourselves in a situation where we have this one quality EP and a case full of relatively cheap EPs that on the secondhand market have lost a considerable amount of value. Little by little we start upgrading but each time we upgrade, we've lost cash on that cheaper eyepiece we're now selling. So with hindsight it would have been better just to buy premium and be done with it. The idea is encapsulated in the expression "when buying premium you only cry once." Or again, paradoxically speaking, "a poor man cannot afford not to buy premium."

Generally speaking, Tele Vue EPs become lifers, so you never have to upgrade again or you can always re-sell them without losing much - if any - money, especially if you have bought them already secondhand. Premium eyepieces, then, simply hold their value more than cheaper ones. They also offer a very important psychological benefit. After a session, for example, you are not left with any nagging feeling of 'what if...', for you know that this end of your optical system is about as good as it is going to get. If the view was poor, if you didn't get the expected detail, it will not be due to the eyepiece itself.

For general DSO viewing, I feel just three eyepieces will suffice for most sessions. If you can, try to work towards a preference of wide field (68º +) offering around 50x, 90x and 125x.

For white light solar viewing, I feel a wide field offering around 50x is ideal. Although not strictly necessary, the extra field of view helps frame the Sun against a gorgeous pitch black background. 

Planetary and Lunar work is a bit of a different game and I honestly believe you need a good run of high power eyepieces. Even the difference of just 1mm in focal length - about 10% to 15% difference of magnification - can be surprising. But the good news is the eyepieces themselves do not need to be widefields, so a little set of Orthos intermingled with TV Plossls would be quite a collection.

Depending on the cash available, you really cannot go wrong with any of the current Tele Vue eyepieces. If we start with the TV Plossl as the benchmark of the Tele Vue brand itself, these will offer sharp, flat fields and excellent edge performance. They are superbly executed eyepieces and the only reason they are not quite premium-premium is simply because they lack the important and expensive features of premium EPs, viz, wide fields and better eye-relief. If you move on up through the different ranges, it is essentially these features that you will be buying into. 

[estwing]

Qualia has hit the nail here, with me it's always the what if that bugs me...the ES eps are fantastic never used one myself but there's lots of great feed back

[Pig]

Lee,

Apart from their brilliant performance and a very comfortable FOV if you were glasses the Delos has a great feature in that the eye relief is adjustable. The adjustment is a great feature for those who don't wear glasses as you can also adjust to suit your needs.

There is nothing worse than spending your cash and waiting for your new toy to arrive only to find you get black outs when you use it

[Orange Haze]

Wow, guys thanks again for taking the time to give such superb advice. I totally agree that's its a bit of false economy simply starting cheap and upgrading time and again. May suit some, but its a great point you make about the 'what if' factor, or simply getting a poor view one night and not knowing if its the seeing or the equipment.

I was tempted to go very short on the new eyepiece but no idea if scope could handle a 3mm or even if id get a lot of chances to use it as I guess seeing would have to be pretty good to make the most of it. So 6mm or 7mm is probably where I will start.

My wonderful Mrs will list so many things I 'could' have spent the money on instead, so perhaps mums the word here. .

[Orange Haze]

And when I say scope, I of course refer to impending 250px Dob and not my trusted friendly 120 frac.

[ollypenrice]

It really is nice in a Dob to reduce the nudging by having an ultra wide field. It also means you can have one EP instead of two, since the wide field will encompass objects too large for the same FL normal EP.

Using a 20 inch F4.1 Dob with a 26 Nagler shows that the TeleVue really does give vastly better off axis performance than a Plossl. Despite the vastly wider FOV the edges are far cleaner in the Nagler than in a Plossl.

Indeed, I don't bother with a coma corrector because I just don't think it's worth it.

Others copy TeleVue's ideas, but who invents them for us? I like to say thank you by buying from those who do the hard part!

Olly

[hippie]

Televue are the best lenses in my opinion that I have tried in my 10" Dob they are superb, My favourite lens size is around 12mm  13mm,  As sky conditions don't  always favour 8mm or higher, Look out for a 40mm / 35mm wide view lens,  You can pick up good second hand TV's on   UK ASTRONOMY BUY & SELL, Saving money,  .

[estwing]

I'm in the widefield junkie camp that's why I went the Ethos route.....but it's not for everyone

[Orange Haze]

Choices choices. I will build a collection over time but will certainly start from the top end rather than lesser pieces. The cost of the scope starts to pale into insignificance once U start down this path doesn't it...

[BillP]

Bill, thank you so much, fantastic to get such great advice. Does the use of the Barlow in your opinion reduce the quality of the view? I assumed my Tal x2 wouldn't exactly complement a quality eyepiece.

A quality barlow will not really impact the quality of the view.  The Tal 2x is a quality Barlow.  FWIW, I am currently doing a critical compare between the Tal 2x and the TV 2x and in testing at this moment, the Tal is coming out on top for planetary.  Surprising given that it is a shorty design.

And as others have mentioned, TVs are excellent in all respects, both optics and build and quality/consistency, and of course you pay for that.  If money is an issue the ES82s and Meade 5000 UWAs are close enough optically not to matter the difference is so small.  Build not as robust, but still very good.  Eyepieces are like cars, you can buy a bunch that all go just as fast, but some are a few 10s of thousands, and others are a few 100s of thousands.  So just depends on the name and the special appointment details.  FWIW, I never felt wanting between these 3 brands of 82s, all put up great images.  I preferred the Meades actually because they had the most neutral tone & I could get more for the price, which is my personal preference.

[bingevader]

I feel that although initially expensive, in the long term, premium eyepieces like those from Tele Vue will probably turn out to be the cheaper option and are never going to be a waste of money.

With the plossls, I'd have to agree. Generally though, TV won't be the cheaper option, because I know TV are the best EPs you can buy, but I'm not going to buy one (unless I win the lottery, but I don't buy a ticket!). This discussion comes up now and again! I've waited and bought the best I can afford. I'm not green with envy, my glass if very much half full. I'm delighted with what I have and I'm very unlikely to change them, they're certainly not going to be a waste of money. There maybe the odd gap but that's another matter altogether!   I'm hopeless at the car analogies, because I honestly don't know what the best car in the world is that I'm supposed to be lusting after! But I don't look at them and think, hmmm, wish I had one of those! Maybe I'm just a bit weird in this respect. We have a Vauxhall Zafira, it's been fab and we're hoping to run it into the ground. The same goes for my EPs, not TVs but they're fab and I'll stick with them 'til the coatings wear off! 

Did someone mention Meade 5000 UWAs?!  Don't forget to check out the Maxvisions too then!

[John]

With the plossls, I'd have to agree. Generally though, TV won't be the cheaper option, because I know TV are the best EPs you can buy, but I'm not going to buy one (unless I win the lottery, but I don't buy a ticket!). This discussion comes up now and again! I've waited and bought the best I can afford. I'm not green with envy, my glass if very much half full. I'm delighted with what I have and I'm very unlikely to change them, they're certainly not going to be a waste of money. There maybe the odd gap but that's another matter altogether!   I'm hopeless at the car analogies, because I honestly don't know what the best car in the world is that I'm supposed to be lusting after! But I don't look at them and think, hmmm, wish I had one of those! Maybe I'm just a bit weird in this respect. We have a Vauxhall Zafira, it's been fab and we're hoping to run it into the ground. The same goes for my EPs, not TVs but they're fab and I'll stick with them 'til the coatings wear off! 

Thats you sorted then. Now how about the OP ?  

[RT65CB-SWL]

Thanks ronin. The radians are still on telescopehouse's site, although maybe its out of date.

Wanted an eyepiece in the 6mm range as this will allow me to test the scope close up on the moon.

Budget would allow me 1 delos or several plossls.

I use a 6mm Radian with a TeleVue Ranger and a Celestron C6/SCT. I have not 'fully' tested in my modified ETX105. The lunar views are awesome! Not in the same league as a 250px I know, but it fulfills my needs...

[jetstream]

At least one really wide field,low power TV may be worth it to you,ie Ethos-but a look through one first would be good to see if you like the view or not,I love it myself.Then a couple of higher power Delos would be nice,my most used planetary EP is the 8mm Delos @ 150x,my conditions don't allow more mag than this most times.Off the Televue topic,Explore Scientific has now offered a lifetime warranty,not sure if it is international,this warranty,combined with the quality of their EP optics gives another great option.