Kellner eyepieces, are they any good?

[jon1000]

Are kellner ep's any good?

Also, found these, are they good nor not http://www.scopesnskies.com/prod/Meade/eyepieceset/individual-maboxset.html

Thanks

[rory]

i think much depends on your telescope , set up and what you want to observe.

in the case of the meade's, personally id buy from the 4000 series (plossl)

i think i remember kellners are ok with long focal lengths and give quite narrow field of view. but youd have to research this ,as i might be wrong.

let people know what telescope you have, it helps them to give advice.

[Capricorn]

Being honest they are not that good.

You can probably get a GSO plossl that will out perform them, the design is 3 lens, the second being an achromat, the first is a simple plano convex.

If you want to know more try:

Eyepiece - Wikipedia, the free encyclopedia

If you have a look at the end of the artical the last diagram is of the Naglers and how the arrangement has changed over time.

[John]

The eyepieces that come bundled with scopes are a modified kellner design and, as you will read in reports on here, those are just about OK to get started with. Plossls and orthoscopics are much better choices.

[LukeSkywatcher]

Kellners will do as starter EP's (if they came with your scope). I wouldnt set out to spend money on them though.

Plossls are a much better choice/design. Not too expensive either................maybe £30 each.

As above...................the Meade 4000 range of EP's get good reviews.

Personally i go for the Vixen NPL range of EP's (about £30 a pop).

[jon1000]

Thanks for your help, I thinking will stay away from them, maybe look at the 4000's

[E621Keith]

Like plossl, not all Kellner are created equal. Those that bundle with kit are usually very poor. The usual advice is to avoid MA, R, H, and short KE eyepieces. Kellner works ok for the longer focal lengths. The design only used three elements, so it is cheaper to built than Plossls or Orthos. As such many manufacture built it down to cost.

I believe KE used to be a popular design in the late 20th century before Plossl replaced it.

[rory]

second hand will save you some dosh.

try here U.K. Astronomy Buy & Sell=

and e bay often have plossl bargains.

i picked up my 32mm meade for about £25 . and ive seen them cheaper.

good luck.

[jon1000]

Thanks everyone

[Merlin66]

I used Kellner's with my first telescope back in the 60's.

For a beginner (who didn't know much and had even less money) on the 6" f8 they worked OK for me for the first couple of years.....

You need to gain experience and practise to appreciate the more expensive eyepieces...

[rwilkey]

The Kellners and MA's are simple 3-element designs and the cotings are not brilliant except in some wide-field examples, best to steer clear of them and go for plossl's, the GSO ones are pretty good, as are the Meade 4000 Series already mentioned.

[RikM]

As above, though I do have a 40mm Fullerscopes Kellner which is excellent in my Skymax. Bought originally for afocal photography rather than looking though.

[twotter]

GSO Revelations and Meade 4000s are pretty much on a par. I've got both types, though I prefer the GSOs.

[acey]

Are kellner ep's any good?

Also, found these, are they good nor not Meade Meade 5 piece Eyepiece set in case

Thanks

Kellner is a type of lens arrangement, not a brand, so asking "are kellner ep's any good" is a bit like asking "are refractor telescopes any good".

There's no reason why a Kellner eyepiece shouldn't (in theory) deliver views as good as a Plossl. Same goes for other similar designs such as Modified Achromat (which you link to). But as has been said, present-day manufacturers tend to use these designs for budget-range eyepieces.

A beginner is unlikely to notice any diffrerence between a Kellner, Modified Achromat and Plossl, except perhaps at high power, where a premium Plossl will be seen to out-perform on planets. An experienced user will see more of a difference.

That's why it's always a good idea to get plenty of experience with whatever eyepiece comes free with the scope.

[SiriusB]

I can't comment on the scope & skies versions but i have some Japanese Kellners.

Generally reckoned only suitable for longer focal ratio scopes,not so great in faster ones, personally i'm happy with them at >f6,.

Nearly all "Kellners" aren't Kellners but Achromatic Ramsdens.

Apparent field of view around 40deg, so a bit narrow.

As others have said there are more worthy ep's available for you to spend your cash on, unless you're on a really tight budget.

Some can show ghost images on bright objects- down to the optical design & the fact they tend to have fairly basic AR coatings.

That said, i really like mine, on axis they give my Orthos a run for their money planetary wise.

And for no adequately explained reason i can think of.,i find they're the best ep's i have for detecting the faintest fuzzies.

[Merlin66]

The Edmund Optics "RKE" (Reversed Kellner Eyepiece) is still a very popular general purpose eyepiece and widely used by amateurs.

I had a 28mm version which performed very well.

[ID1 john Ei3]

Being honest they are not that good.

You can probably get a GSO plossl that will out perform them, the design is 3 lens, the second being an achromat, the first is a simple plano convex.

If you want to know more try:

Eyepiece - Wikipedia, the free encyclopedia

If you have a look at the end of the artical the last diagram is of the Naglers and how the arrangement has changed over time.

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HERE GOES HAVE A LOOK SEE http://www.swindonstargazers.com/beginners/eyepieces.htm