Nagler or Radian?

[Mr Flibble]

Hi everyone,

If you lacked a decent planetary eyepiece and decided to take advantage of a 20% TV offer, which would you choose out of :

1) 3.5mm Nagler, mag. x214, 82 deg FoV and 12mm eye relief

or

2) 4mm Radian, mag. x189, 60 deg FoV and 20mm eye relief?

Would I benefit from one of these with my 6inch scope or should I go for a more budget eyepiece?

Thanks.

P.S. I don't wear glasses.

[brianb]

The Baader Genuine Ortho performs as well as or better than Naglers & Radians for planetary work; the "small" field of view isn't an issue as a planet is such a small object. It also costs a lot less. If you can't put up with the limited eye relief of the ortho then IMO the Radian is a better eyepiece than the Nagler ... for planetary work (better contrast). Less glass is usually better.

And the 3.5 Nag is just too powerful ... 30x per inch is as much as you can expect to get benefit from, and only then on rare nights of unusually steady seeing.

[Mr Flibble]

I see the Baader Ortho comes in 5mm as the shortest focal length. That would give me x150 magnification. Will that be enough as a planetary eyepiece?

Also, would I get more value for money out of the Ortho due to its lower magnification compared to the Radian which I'd presumably use less because I'd need to rely more on good seeing?

Thanks.

[brianb]

I see the Baader Ortho comes in 5mm as the shortest focal length. That would give me x150 magnification. Will that be enough as a planetary eyepiece?

Probably 8 or 9 nights out of 10, yes. But you might want more on those rare nights of steady seeing.

Hard call. Difficult to choose between an 8mm BGO + a decent 2x barlow and a 4mm Radian.

Also, would I get more value for money out of the Ortho due to its lower magnification compared to the Radian which I'd presumably use less because I'd need to rely more on good seeing?

Yes.

[Mr Flibble]

Hard call. Difficult to choose between an 8mm BGO + a decent 2x barlow and a 4mm Radian.

Yes.

I think in terms of value for money it may be better if I invest in longer focal length eyepieces which will have plenty of use and then invest in a decent barlow for planetary use when conditions allow. I'll retain the eye relief and I won't have an expensive eyepiece that I'll only occasionally use.

With TV I could aim to collect the 11mm and 15mm plossls. Used with the x2.5 powermate it would give me a full set of magnifications - x170, x125, x68, x50. With the 20% offer I could try one of the plossls first to see if they offer a worthy improvement over my current eyepieces, and if so, aim to complete the set in time.

The only thing I'm not sure about is how the quality of view differs, if any, between a longer f/l eyepiece which is barlowed and an unbarlowed higher f/l eyepiece?

Thanks.

[brianb]

how the quality of view differs, if any, between a longer f/l eyepiece which is barlowed and an unbarlowed higher f/l eyepiece?

Well it depends on the quality of the barlow & the coatings. "Long eye relief" eyepieces (including Radians) effectively have a built-in barlow so the point may be moot ... unless you're comparing e.g. the view between a 9mm BGO and a 18mm BGO with a 2x barlow, in which case I can tell you that - even with a barlow of very good quality (Celestron Ultima SV 2x) - the barlowed view is degraded slightly but the longer eye relief may be more comfortable.

A mediocre barlow will wreck the view whatever eyepiece you use.

Oh, and at about the same price point, for planetary work the Baader Genuine Ortho outperforms any Plossl - including the Televue ones - by a considerable margin.

[Mr Flibble]

So I really need to go down the ortho route to get the best out of a planetary eyepiece. I need to give some thought between the 5mm BGO with x150 mag or the 9mm BGO with x2 Barlow to give a mag of x166 and longer eye relief.

I may go for the 5mm BGO to keep the best image.

Thanks for giving me this information, its exactly what I'm after. Much appreciated

[Moonshane]

my own policy with eyepieces is that you maybe have 3-5 main eyepieces and with these I tend to go for wider field as they serve more purposes, being used for general observing etc but also planetary work and finding etc.

other than this I have bought what I considered as 'fillers', mainly by buying TV Plossls and BGOs as I don't really like Barlows / Powermates but they do a good job.

the point is that not everyone can afford a full set of Naglers and Radians and especially when many of them will not be used all the time. BGOs and TVPs are very cheap compared with Naglers and Ethos etc.

what has surprised me though is that when looking at planets and the moon, I now reach for the 'cheap options' as they quite simply give a better view to my eyes than the more expensive wide fields.

e.g. my 12.5mm BGO (£70) is to me anyway better for Jupiter than my 13mm Ethos (£350 used). even my 7mm BGO is 'better' than my 8mm Radian. I have found that often the seeing is better with one eyepiece than another and the next time it's better with the other as seeing changes. this is whay I took the slightly mental approach of buying a 6-3mm zoom, 7mm, 8mm, 9mm, 10mm, 11mm, 12.5mm, 15mm and 18mm 'fillers' just to give me more options. and yes, I do use them all quite regularly.

I just seem to prefer the cleaner brighter look through the orthos for the purpose they have been designed. these comments also apply to the TVPs but I personally also prefer the view through the orthos on planets at least.

OK we are talking about the difference between one side of a hair and another but you don't need to pay big bucks for excellent planetary eyepieces.

all that said and to answer your direct question, I think you'd get more use out of the 4mm Radian more often and the field would be quite acceptable at 60 degrees. in fact though, you might find that 150x is all you can get on even more nights and this would mean the 5mm Nagler T6 might be a good choice. you would certainly see the benefit of good quality eyepieces with any scope and assuming yours is f5 then even more so in my experience. As others have said, another option is a 9mm BGO and a barlow.

eyepieces are a right royal pain with so many choices!

[brianb]

I just seem to prefer the cleaner brighter look through the orthos for the purpose they have been designed. these comments also apply to the TVPs but I personally also prefer the view through the orthos on planets at least.

Glad I'm not the only one!

[John]

I've compared Baader Geniune Orthos and classic Ortho's directly with Nagler Type 6 equivalents (including the 3.5mm) on a variety of objects on a number of occasions and did not notice the orthos out performing the Naglers in any respect. As I like the very wide field of view and more generous eye relief of the Naglers I was very satisfied with them as high power eyepieces. They do cost a lot more than the orthos though.

Thats just my experiences, with my eyes, my scopes and my observing conditions. Others, as you can see, will reach other conclusions.

I've never tried a Radian so I can't comment on those.

[Moonshane]

as I say John, it surprised me too!

that said, I still love my Ethos for other things.

I have not used a Nagler and can only compare with the EPs I have. will be interesting if we get chance to have a play about and see if you can use one of my Radians and I can use a Nagler from somewhere.

Brian - definitely not - Orthos are ace!

[John]

as I say John, it surprised me too!

While I found the Baader GO's and Nagler T6's were more or less equal, the Pentax XW (10mm) and the Ethe are, to me, a touch better again.

I've noticed this in a tangible way when observing objects right on the edge of the seeing conditions / scope / observer capability - all the eyepieces mentioned will show them but the XW and Ethe just make them that little bit easier to spot.

But that's just one observers findings of course - "your mileage may vary" as the saying goes

I'd love to have a look through some Radians Shane . Pentax XO's, Zeiss Ortho's, TMB Moncentrics and Astro Physics SPL's are also on my "hit list" if I ever get a chance to try them

[Nexus 6]

Boy those Baader Orthos must be good, I keep reading so at least!

Have ordered the 7mm to see how it performs, that will really push the power for me to 335x, will be interesting to see how Saturn looks.

Apologies David did not mean to butt in on your thread, the Radians are certainly great for the reasons already given but yes Televue ep's are a bit pricey, if you are going to buy any now is the time! Not every day we get such a great discount with TV gear.

[Mr Flibble]

Have ordered the 7mm to see how it performs

Apologies David did not mean to butt in on your thread, the Radians are certainly great for the reasons already given but yes Televue ep's are a bit pricey, if you are going to buy any now is the time!

On the contrary, I value your input . Will be interesting to hear how you get on with the 7mm.

The eyepiece world is certainly complex. For me, working out the required focal lengths is pretty straight forward but deciding which type or make is a minefield! I shall try the BGO for my high power eyepiece going by the high recommendations here.

[ollypenrice]

I have a 4.8 Nagler and 4mm Radian. On the planets the Radian is comfortably ahead with no ghosting and less glass and more eye relief. I don't know the Genuine Orthos but perhaps I should!

Olly

[brianb]

I don't know the Genuine Orthos but perhaps I should!

The "issues" with the BGOs are, by modern standards, a rather small apparent field of view and a restricted eye relief (similar to a Plossl of similar focal length). The first is of course not an issue with planets if your scope has motor drive. The second can be a real problem in the shorter focal lengths. My "planetary" eyepieces of choice are 9mm & 12.5mm BGOs but then my main scope is f/10 ... shorter than about 8mm I'd prefer the Radian.

As Olly says, the Naglers may have their charms (especially in fast Newtonians) but they are not good for planets.

[Stu]

This is a very interesting thread, if a little hard to draw any firm conclusions from.

I have a f20 mak and recently bought a 13mm ethos which gives x 307, which gives amazing views on quite a range of objects when the seeing is good. Because the mak had such a small field of view, the ethos really helps maximise what you can see.

I'm also looking for some higher power ep's for my 106mm astro tech refractor. I had been looking at 3.5 and 5mm naglers, having already got a couple but from reading this I do wonder whether to give the BGO's a try at 5mm

Any thoughts?

Stu

Stu

[John]

As Olly says, the Naglers may have their charms (especially in fast Newtonians) but they are not good for planets.

I'm sure this won't suprise you Brian but I've found Nagler Type 6's excellent for planetary viewing

I fully accept that you don't prefer them for that purpose (or any other perhaps) but to say that they are unsuitable for planetary use is misleading IMHO. Or maybe you have not tried any Type 6's ?.

[brianb]

maybe you have not tried any Type 6's ?.

I've tried 5mm Nag type 6, 5mm Radian & 5mm BGO "head to head" in a TV 102 (not mine) & I much preferred the Radian to the Nag. The view in the BGO (same scope) was better still, if slightly less comfortable because of the short eye relief.

[Stu]

What eye relief do the BGO's have? Can't seem to find a spec on them other than comments that it its short but manageable.

I guess the unfortunate reality is that I will have to try the BGO out to see which I prefer. Might just buy a 7mm so I can do a direct planetary comparison with my 7mm type 6

Oh to have enough money to have a set of each :-)

[spaceboy]

Given there is a 20% off TV's at the moment it's probably pointless me mentioning this but did you consider a TMB clone? £38 delivered 58' AFOV and plenty of eye relief even in the shortest of FL. Pound for pound I don't think these eyepieces can be beaten. Short FL EP's don't tend to get much use given usual seeing conditions and it can some times pay to buy a budget or s/h EP just to see how much use it will actually get in your setup. This was my plan and with any chance I got the budget ep's were used to see how they coped with good and bad seeing. It was a shock to find that even on only reasonable nights they spent some time in the focuser. Given how well a budget EP had performed in my setup I felt I could easily warrant an expensive upgrade. Thankfully along came a well timed 20% off Televues sale and the rest is now history

SPACEBOY

[Stu]

Spaceboy, I'll probably end up getting a 17t4 and a couple of type 6's in the sale and then trying some BGO's for comparison before deciding what to keep.

Apologies if this has ended up high jacking the thread at all, wasn't my intention.

[brianb]

What eye relief do the BGO's have? Can't seem to find a spec on them other than comments that it its short but manageable.

Standard for orthoscopics: 0.85 x the focal length of the eyepiece. (cf 0.8 x F for Plossls)

What is "manageable" depends on personal comfort, some people tolerate a small eye relief well, other people hate it. But the eye relief of the 12.5mm BGO is almost 11mm which is not too bad... and personally I think the flat topped design is better for the short focal length / small eye relief versions than the "volcano top" design used by some other manufacturers, which can have a tendency to impact painfully with the cornea.

[Stu]

Thanks brianb.

That gives 4.25mm on the 5mm, seems pretty tight. Is it manageable?

[John]

Thanks brianb.

That gives 4.25mm on the 5mm, seems pretty tight. Is it manageable?

It's manageable but the question is is it pleasant to use and is your eye relaxed when viewing with that little eye relief. I reckon that varies with individuals - some will find it unacceptable while others will wonder what the fuss was all about.

Personally I find the "volcano" top orthos easier because they seem to fit into the eye socket easier making the eye lens more accessible.

I think the only way to find out is to try for yourself !.