New Plossl eyepieces?

[Lady Fraktor]

The new Starbase 80mm refractor that is being offered through Takahashi also has a set of Orthoscopic Plossl eyepieces that I am trying to find more information about.
https://www.takahashiamerica.com/starba ... mm-ep.html

On a Japanese page that I am trying to find again they were described as true Asymmetrical eyepieces and the corresponding diagram showed them as proper design using 3 different glass types.
On another they were shown as 2 different glass types though still with the Asymmetrical drawing.
Takahashi only says they are Plossl with a 45° AFOV which could indicate they are actually Asymmetrical eyepieces.

Still trying to find out more, I went on that other site but they are to busy arguing if it is actually a Takahashi or not even though all of the literature and the owner of Land, Sea and Sky have said it is not and only offered through Takahashi...

If anyone hears if these are actually Asymmetrical or just Symmetrical let me know

[notFritzArgelander]

These would then be extremely interesting if asymmetrical. Also, fully coated? Or fully multi coated?

[Lady Fraktor]

That is also not mentioned so needing to find out, on this page they are shown as Asymmetrical but with 2 glass types and nothing of the coatings.
https://scopetown.co.jp/SHOP/108449/list.html

I have noticed that Takahashi Japan and America are the only ones that seem to be offering this telescope and eyepieces at the moment.
Takahashi EU does not list either and makes no mention of it in their news postings.

[j.gardavsky]

According to the scheme of the eyepieces, they are looking like a pair of doublets BK7/F2 (or BK7/F4), as the relative surface curvatures differences might let me believe.
The Abbe ortho, also shown, has 3 different glass materials.

Best,
JG

[notFritzArgelander]

That is also not mentioned so needing to find out, on this page they are shown as Asymmetrical but with 2 glass types and nothing of the coatings.
https://scopetown.co.jp/SHOP/108449/list.html

I have noticed that Takahashi Japan and America are the only ones that seem to be offering this telescope and eyepieces at the moment.
Takahashi EU does not list either and makes no mention of it in their news postings.

Thanks for the link. My Japanese literacy is not what it once was, but I have my dictionaries. Perhaps in three days and a cloud of dust I can have an answer?

[Lady Fraktor]

Thank you for your thoughts JG, I am still trying to find the first description as it showed three different glass types.
The two outside elements of differing elements from each other with the two inside elements being same.

Good luck with your Japanese nFA, unfortunately my translation is provided by Google

[notFritzArgelander]

Thank you for your thoughts JG, I am still trying to find the first description as it showed three different glass types.
The two outside elements of differing elements from each other with the two inside elements being same.

Good luck with your Japanese nFA, unfortunately my translation is provided by Google

Google does a miserable job with Japanese...... It can save some time and might be useful as a jumping off point but I cannot recall a time when it was adequate by itself.

[Lady Fraktor]

It is barely adequate in most languages at times, at least with some languages you can infer close enough to what is being said.
I think the person who wrote most Cinglish manuals also translated for Google

[Don Quixote]

Very interesting stuff. I will check back to see what conclusions you all draw.
Thank you Gabby.

[notFritzArgelander]

Well.... actually it wasn't such hard work after all.

Google translate provided:

In the early days, it was made by Cook in England and Steinheil in Germany. This is an eyepiece that is an achromat that combines two lenses from Ramsden. Properly made in Japan, the ghost is inconspicuous, and since there is little spherical aberration and distortion, it is an almighty eyepiece that can be used from low to high magnification. By the way, NIKON's orthoscopic eyepieces, which are still very popular, were of the PL type.

Which requires only mild correction to:

Initially this design was made by Cook in England and Steinheil in Germany. This is an eyepiece that is an achromat combining two lenses like the Ramsden. Precision made in Japan, ghosting is inconspicuous, and since there is little spherical aberration and distortion, it is an excellent eyepiece that can be used from low to high magnification. By the way, NIKON's orthoscopic eyepieces, which are still very popular, were of the PL type.

So unfortunately the coatings question is not addressed.....

[Lady Fraktor]

It does not address if it has two or three glass types either, I will check some more after the weekend to see if I can find the first description I found.

[j.gardavsky]

Well.... actually it wasn't such hard work after all.

Google translate provided:

In the early days, it was made by Cook in England] and Steinheil in Germany. This is an eyepiece that is an achromat that combines two lenses from Ramsden. Properly made in Japan, the ghost is inconspicuous, and since there is little spherical aberration and distortion, it is an almighty eyepiece that can be used from low to high magnification. By the way, NIKON's orthoscopic eyepieces, which are still very popular, were of the PL type.

Which requires only mild correction to:

Initially this design was made by Cook in England and Steinheil in Germany. This is an eyepiece that is an achromat combining two lenses like the Ramsden. Precision made in Japan, ghosting is inconspicuous, and since there is little spherical aberration and distortion, it is an excellent eyepiece that can be used from low to high magnification. By the way, NIKON's orthoscopic eyepieces, which are still very popular, were of the PL type.

So unfortunately the coatings question is not addressed.....

Thank you notFritz for the fun!

Cook and Steinheil are triplets, achromat is a doublet.
It's all somehow weird.
Now, I don't know where I am, Plössl - triplet - Ramsden, in Zen they are all the same, and suddenly quite different,
I must download some ritual Japs dance, it helps, they say.
Right now, Steinheil turns into Frankenstein of Ramstein, oh that's the base, but everything is basic, and Stein like Stein, ...

Taking a drink,
JG

[notFritzArgelander]

Well.... actually it wasn't such hard work after all.

Google translate provided:

In the early days, it was made by Cook in England] and Steinheil in Germany. This is an eyepiece that is an achromat that combines two lenses from Ramsden. Properly made in Japan, the ghost is inconspicuous, and since there is little spherical aberration and distortion, it is an almighty eyepiece that can be used from low to high magnification. By the way, NIKON's orthoscopic eyepieces, which are still very popular, were of the PL type.

Which requires only mild correction to:

Initially this design was made by Cook in England and Steinheil in Germany. This is an eyepiece that is an achromat combining two lenses like the Ramsden. Precision made in Japan, ghosting is inconspicuous, and since there is little spherical aberration and distortion, it is an excellent eyepiece that can be used from low to high magnification. By the way, NIKON's orthoscopic eyepieces, which are still very popular, were of the PL type.

So unfortunately the coatings question is not addressed.....

Thank you notFritz for the fun!

Cook and Steinheil are triplets, achromat is a doublet.
It's all somehow weird.
Now, I don't know where I am, Plössl - triplet - Ramsden, in Zen they are all the same, and suddenly quite different,
I must download some ritual Japs dance, it helps, they say.
Right now, Steinheil turns into Frankenstein of Ramstein, oh that's the base, but everything is basic, and Stein like Stein, ...

Taking a drink,
JG

I suppose in some strange sense you could, if not careful, talk yourself into a Plossl being kind of sort of like a Ramsden maybe sort of. Take a Ramsden, two positive power lenses, and replace the plano convex lenses with two achromatic positive power doublets.

Yep, I don't want to go there..... Marketing speak is wonderful isn't it?

[j.gardavsky]

...
I suppose in some strange sense you could, if not careful, talk yourself into a Plossl being kind of sort of like a Ramsden maybe sort of. Take a Ramsden, two positive power lenses, and replace the plano convex lenses with two achromatic positive power doublets.
...

Hello notFritz,

a sort of continuation of Ramsden may be the achromatic pair with its ring of fire.
The so called "Plössls" or "symmetric" coming in the EP kits from the Far East may be just achromatic pairs of one or another sort, still with some ring of fire.
The next would be the (asymmetric) Plössl, better correcting the intrinsic CA,
Even slightly better is the Symmetrical (Plössls) of Zeiss with its intrinsic Strehl of 0.985, beating by a small marging the Nagler (symmetrical) Plössl 0.975

The links are here:
https://www.telescope-optics.net/eyepie ... tion_2.htm
https://www.telescope-optics.net/eyepiece_raytrace.htm

Best,
JG

[Don Quixote]

Wow!
You all have expanded my understanding...
I think my head is about to Pop!

[j.gardavsky]

Wow!
You all have expanded my understanding...
I think my head is about to Pop!

Hello Mark,

don't worry, its all just about the 'ring of fire', and about the Strehl.

Best,
JG

[Don Quixote]

The "ring of fire". Heck now I understand perfectly.
Watch "Johnny Cash - Ring of Fire" on YouTube

[Don Alvarez]

an eyepiece that calls itself "almighty" cannot be denied.

[notFritzArgelander]

an eyepiece that calls itself "almighty" cannot be denied.

But only if you believe Google translate....

[Don Alvarez]

But only if you believe Google translate....

They wouldn't put anything on the internet that isn't true.