11 replies to this topic

[MrsM75]

Is 3 lenses elements in 2 groups always a Kellner?

 

So here a pic of the Sarblue Mak 20mm ep that came with the scope, it very comfortable and clear, eventhough it say 50 deg, but it seem bigger than that when view inside, I thought it was 60 deg.

 

There a video of a man in Youtube he disassemble this ep then put it back together, he said it 3 lenses elements in 2 groups. He didn't; say it if it a Kellner, Reversed Kellner or Modified Achromat

 

This is an eyepiece that I will never let go, it just so comfortable to look through. What exactly is this thing? It looks plastic but it actually glass in there, 3 elements 2 groups.

 

 

 

 

[triplemon]

Nope.

The eyepice Kellner created has a PCX field lens and an achromat as eye lens.

All the other permutations or optimizations with biconvex lenses are not a Kellner. And since you are the onlty one who watched that youtube video and knows where to find it - you would be the only one to tell what is in that eyepiece ...

[MrsM75]

Nope.

The eyepice Kellner created has a PCX field lens and an achromat as eye lens.

All the other permutations or optimizations with biconvex lenses are not a Kellner. And since you are the onlty one who watched that youtube video and knows where to find it - you would be the only one to tell what is in that eyepiece ...

https://www.youtube....h?v=4cVid9aXkD8

 

It this Youtube video, skip to starting at 14:25 you will see he open the eyepiece took it out, he said 3 lenses elements in 2 groups.

 

What eyepiece is this? It doesn't look like Kellner, I thought it was Plossol, but sure can't be if it 3 lenses and 2 groups.

[MrsM75]

Maybe it a Reverse Kellner?

[MrsM75]

Can someone help me figure out what this cute thing is, I actually like it very much, my Maks love it. 

[Jay_Reynolds_Freeman]

Certainly not a classic Kellner design. The two most similar designs that I know of are the Konig and Edmund's RKE.

 

Clear sky ...

[MrsM75]

Certainly not a classic Kellner design. The two most similar designs that I know of are the Konig and Edmund's RKE.

 

Clear sky ...

 

It does seem like the Edmund's RKE. Is the Edmund's RKE has 3 lens elements and 2 groups too Sir?

 

It just very comfortable in the eyes. And it definitely look bigger than 50 deg when view inside the eyepiece (eventhough it say 50 deg). 

[T1R2]

He called it a Reverse Kellner after taking the lenses out. 

[MrsM75]

He called it a Reverse Kellner after taking the lenses out. 

 

oh? ha.! I must miss that part. Reverse Kellner isn't it only 45 deg? But in the Sarblue booklet that come with the scope it say it is 50 deg.

And I know for SURE it look bigger than 45 deg. I have alot of those Vixen NPL and Vixen SLV both are 50 deg, and this Sarblue eyepiece (Reverse Kellner) but seem to have bigger fov than the Vixen ep 50 deg.

 

So it plastic lens then, Reverse Kellner. But this is the most comfortable eyepiece I ever look through, it even more comfortable than the 50 deg Plossl.

 

oh and it more clear than the Vixen NPL 20mm Plossl too, this Sarblue eyepiece win the Plossl.

Edited by MrsM75, 02 May 2025 - 06:15 AM.

[MrsM75]

The man in the Youtube he said it Konig design, Reverse Kellner.

 

So does that means the elements lens in this Sarblue ep is plasticccc??

 

omg it plastic isn't it? But it such a good eyepiece though, I like it even more than the 50 deg Plossl.

 

plastic??

 

Edited by MrsM75, 02 May 2025 - 06:22 AM.

[*skyguy*]

Yes ... Reversed Kellner.

 

Check out this diagram of eyepiece types:

 

http://www.quadibloc...ience/opt04.htm

[Starman1]

Where do you get the idea the lenses are plastic?

This is unlikely.

It could be a König, or an RKE (which stands for Rank--Kaspereit--Erfle, not reverse Kellner) or simply a modified simple eyepiece.

It doesn't matter what it is if you like the eyepiece.