Vixen Lanthanum EP's

[moondog]

Bought a couple of Lanthanum's the other week but only managed to use them last night.

So - here's what I found:-

Why Lanthanum's?

1) I thought the good Eye Relief would suit me better

2) I got them for a good price! (They are normally £105 to £125 each - I got them for £75 each)

Technical

5mm - 45 deg apparent FOV (Field of View)

9mm - 50 deg apparent FOV

Eye relief on both - 20mm

Both are substantial 1/1/4 inch EP's. About 3 times size and weight to the equivalent Plossls

Well built, with natural rubber eyecups, nose chamfer and retaining groove.

The multi coatings are the best quality that I've seen on any optical lens.

I compared the Lanthanum's with the two equivalent Plossls that I have. A 6.3mm TAL Super Plossl (50 deg FOV) and a 10mm Antares Plossl. Plossls usually have Eye Relief that is 70 percent of the focal length of the EP. Giving the 6.3mm EP just over 4mm ER, and the 10mm EP 7mm ER. I do wear glasses but up till now I've been able to use a scope without them - but not for long as my eyes are changing for the worse. I will soon have to use my glasses - hence the new EP's

The Test

I wanted the new EP's for the Planets and the moon. There was a good moon last night so I used that as the test.

Scope - TAL 100RS F10 4 inch (100mm) refractor. Standard apart from Moonfish 2 inch diagonal. Seeing 4/5?

First up 10mm Antares Plossl. Theophilus on the terminator was a splendid sight. The Antares gave me a fairly good view at 100x but the shadows had a bluish cast, contast not brilliant. Wearing my glasses I could only see less than half the available FOV.

Substituting the 9mm Lanthanum I found that this was parfocal with the Antares. This helped in swapping the EP's. Immediately I could see that the bluish cast had gone, to be replaced with black shadows. The contrast and sharpness were better. The important thing is that I could see the whole FOV with glasses - a great improvement.I tried other targets - such as Posidonius with the same results.

Next up the 6.3mm TAL Super Plossl. This EP had good solid black shadows with good contrast for the 158x magnification. Problem was that I could only see a very small part of the FOV with glasses. Without glasses I've had to virtually press my eye to the lens. The 5mm Lanthanum gave me a quality of image at 200x similar to the TAL at 158x - the difference for me is that I could see the whole FOV.

As the seeing was good I tried to go over the theoretical limit ( for my scope) of 200x by using the TAL 2x barlow with the 9mm Lanthanum. This gave a far better image than I expected at 222x - very usable.

For me the fact that I can see the whole of the FOV is more important than the fractional improvement in light and contrast that an orthoscopic could give me.

MD

[russ]

MD, Excellent review of an excellent eyepiece range. I agree wholeheartily with your conclusion too.

Russ

[lunator]

MD

Glad the eyepieces worked well for you.

Lanthanums are very good eyepieces and I have yet to meet anyone who bought them for the same reasons you did being dis-appointed.

I did look at them myself recently but I don't need long eye-relief and the extra glass in the design can make it harder to observe/measure faint stars. But I know that if I need LER eyepieces Lanthanums would be top of my shopping list

Cheers

Ian

[tom.yates]

Excellent eyepieces i use mine all the time above my naglers if i could have looked through the lanths before buying the nags i could have saved a lot of money.

[moondog]

Thanks Tom

With the excellent things that are said about the TV Naglers it does come as a bit of a (nice) surprise that the Lanthanum's are considered to be of similar quality. I look forward to many hours using them with the TAL frac. The overall optical quality of the set up that I have now is great - even considering that the 2 Lanthanum's cost almost as much as the TAL!.

MD

[Saso]

Excellent review. Thanks.

Saso

[tom.yates]

A lot of things are said about eyepieces some true some not so true the lanths are a very good quality eyepiece for all round use i compared a 13mm wa lanth with a 13mm type 6 nag and found that the lanths was brighter an d gave a more pleasing few the test was done using a 7" Astro Physics Refractor on diffrent targets Planets, deep sky , the only place the nag won out was on it's field of view the test was done on diffrent nights, with 2 people coming to the same conclusion.

[FLO]

Glad the eyepieces worked well for you.

Lanthanums are very good eyepieces and I have yet to meet anyone who bought them for the same reasons you did being dis-appointed.

Couldn't have said it better

Great review MD

[Gordon G]

Hi MD

Good review, and agree,

Never considered Lanths's before, Tom let me look through his a Kielder a few years ago, Sold on them straight away, Went out and got some. I use Lanths most of the time and have outlasted some of the scopes that i have had and sold on !!. Lanths's are keepers.

Top report 8)

Cheers

Gordon

[moondog]

Gordon & Tom

Since the last few nights have been clear I have been putting the Lanthanum's through their paces. I've been so impressed with them that I've ordered another two before the price goes up. My lens collection is now certainly worth more than the scope!

On a more practical point the Lanthanum's are excellent to use for eyepiece projection. Their long eye relief and more particularly their large eye lens making it easily possible to use even the 5mm with a compact digital camera. The only EP I could use before for EP projection was a 2x barlowed 25mm plossl. The 6.3mm TAL plossl, whilst surprisingly good optically would not work. See my post in the Lunar section (4th April) this is only my second digital image, and my first with a Lanth.

Cheers

MD

[tom.yates]

What Lanths are you getting? Would recommend the Wide angle lanths Where are you ordering them from as me and Gordon got the Wide angle for around £80 each the standard lanths go for around £50 secondhand PM me for more info.

[FLO]

Just had a quick play (daytime viewing thru an APO refractor) with the 5mm Lanthanum bought recently from Russ.

Compared to an Orthoscopic, the Lanth had slightly less contrast and brightness - nothing that would worry me but noticeable nonetheless.

It also had noticeable pincushion distortion. Whilst this would annoy me if I were using it for daytime observing, it is not an issue for astro as it would only really show if you were panning - not something you normally do with a high-power eyepiece.

I did find it a very comfortable, easy to use eyepiece with excellent resolution right to the edge of its 45 degree FOV. For that reason, its a keeper.

I will be using it for astro observing tonight but doubt that I will see anything that will change my opinion

UPDATE: Astro observing only confirmed my opinion - a really comfortable eyepiece to use but not one that will threaten a good orthoscopic.

[tom.yates]

Very intresting Steve , I have had no probs with the wide angle eyepieces no pin cushioning and no probs with contrast against my nags or TMB 'S OR MY Rads £ for£ I would say they are better value for the difference in money.

[FLO]

The wideangles are a quite different design.

BTW, I read somewhere that the new Stratus eyepieces are essentially chinese clones of the Vixen/Orion Superwide Lanthanums?

[GazOC]

Thats right Steve, the Orion Stratus/ Baader Hyperions are pretty much the same eyepieces as the wide lanths.

[FLO]

.... but cheaper

[The Warthog]

Nice review. Something to think about. Thanks!

[GazOC]

Steve, Tom

http://www.svenwienstein.de/HTML/hyperion_-_english_version.html

Very well put together piece.

[FLO]

Nice find Gaz,

Good kit gets cheaper every year

[tom.yates]

YEP NICE FIND MATE.

[FLO]

UPDATE:

Having used the Lanthanum for a while…

Though optically it doesn’t beat a good orthoscopic, it has become my favourite high-power eyepiece. The views are pleasing and it is just so comfortable to use 8)

[GordonCopestake]

You can't beat radians for long eye relief quality eyepieces

[FLO]

You can't beat radians for long eye relief quality eyepieces

I have never seen thru a Radian but hope to, one day.

[GordonCopestake]

I have a 4mm one for high mag views and it's like looking though a 32mm plossl. The naglers are even better, but i find the 82 degree field can be distracting. 60 degrees is about right for me. And the radians are cheaper than the naglers. You can get radians for about £100 each second hand. Theres a 10mm one on ebay at the moment on only £10, it's on my watch list heh

[FLO]

fantastic review in Practical Astronomer

Probably time I took out a subscription...