-
Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.
Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
Two classics side by side (3 Viewers)
- Thread starter kimmik
- Start date
henry link
Well-known member
Optolyth 30x60 and Noctivid.
Is it the 10x42 or 8x42? I've been wondering whether the eyepiece field lens singlet is in both or just the 10x.
Is it the 10x42 or 8x42? I've been wondering whether the eyepiece field lens singlet is in both or just the 10x.
Last edited:
Funny that the barrels are almost transparent to the X-rays but the Leica and Optolyth logos aren’t fully.
John A Roberts
Well-known member
The Optolyth is perhaps more likely the 22x60 version, that had a shorter eyepiece.
e.g. There’s one currently for sale on-line at Acer Optics UK (aceopticsbath):
And the only image that we have of the Noctivid optics is that of the 10x42:
So considering the lens group spacings compared to the drawn image, the 8x42 version?
John
p.s. Of course it's the Noctivid - and not the Noctilux as I initially called it - I got my Leicaspeak confused!
e.g. There’s one currently for sale on-line at Acer Optics UK (aceopticsbath):
And the only image that we have of the Noctivid optics is that of the 10x42:
So considering the lens group spacings compared to the drawn image, the 8x42 version?
John
p.s. Of course it's the Noctivid - and not the Noctilux as I initially called it - I got my Leicaspeak confused!
Last edited:
henry link
Well-known member
Hi John,
Yes, the scope could be the 22x60. I don't have any information about that model, but the 30x60 eyepiece looks about the same length as the one in the x-ray to me in brochure images I have from the 1980s. Presumably Kimmik will enlighten us.
What about those prisms? Optolyth specifies 3 prisms for all their scopes in my brochures. What could they be to keep the eyepiece and objective lenses inline. The x-ray is not very helpful to me.
And what about the eyepiece lenses? Optolyth specifies 6 lenses total for the 30x60 (I don't have lens number specs for the 22x60). If the objective is a cemented doublet that leaves 4 for the eyepiece. What design would that be to match the approximately 56º AFOV.
I think you're right about the x-ray image probably being the 8x42. Presumably Kimmik will let us know about that too.
Henry
Yes, the scope could be the 22x60. I don't have any information about that model, but the 30x60 eyepiece looks about the same length as the one in the x-ray to me in brochure images I have from the 1980s. Presumably Kimmik will enlighten us.
What about those prisms? Optolyth specifies 3 prisms for all their scopes in my brochures. What could they be to keep the eyepiece and objective lenses inline. The x-ray is not very helpful to me.
And what about the eyepiece lenses? Optolyth specifies 6 lenses total for the 30x60 (I don't have lens number specs for the 22x60). If the objective is a cemented doublet that leaves 4 for the eyepiece. What design would that be to match the approximately 56º AFOV.
I think you're right about the x-ray image probably being the 8x42. Presumably Kimmik will let us know about that too.
Henry
William Lewis
Wishing birdwatching paid the bills.
It looks like a Schmidt first, schmidt - pechan - but that's only 2... I believe the swaro CTC uses sp prisms and is a similar design. I believe kimmik stripped a optolyth to fit image stabilising actuators so he will certainly have the answer!
John A Roberts
Well-known member
Hi Henry (post #6),
The only Optolyth catalogue that I'd previously found on the net seems to date from around 2008,
and a quick search yesterday didn’t come up with any detailed info about the earlier models, hence my qualification.
In terms of older technology where space is not at a premium (unlike with most binoculars),
the optically most efficient and cheapest way to keep a light column in line pre- and post-prism travel,
would be a Porro prism pair [preferably the lesser offset Type II (?) ] combined with a rhomboid prism *
As you know, a rhomboid displaces a light column without altering its orientation, and that could be the first prism shown in the image (?)
- - - -
By way of illustration:
From: Rhomboid Prisms | Edmund Optics
So imagine the lower image on its side in front of this Porro Type II prism:
* Using Porro prisms would have avoided the issues of: non phase coated roof prisms; non-TIR surfaces, and;
dual function surfaces with their conflicting coating needs. Additionally, Porro prisms have more relaxed demands in terms of grinding precision.
And in terms of prism numbers, Porro Type II prisms can be fabricated in various ways, with the parts then cemented together
resulting in three, two or one piece prism assemblies.
John
p.s. A Porro and rhomboid prism combination is used in the Zeiss 20x60 S mechanically image stabilised binocular.
But the rhomboid prisms are behind the main prisms, and located within the eyepieces that swivel to provide IPD adjustment.
See the image from Henry in post #11 at: High end porro's
(For more on the Zeiss 20x60 S see: Roger Vine's Zeiss 20x60S review )
The only Optolyth catalogue that I'd previously found on the net seems to date from around 2008,
and a quick search yesterday didn’t come up with any detailed info about the earlier models, hence my qualification.
In terms of older technology where space is not at a premium (unlike with most binoculars),
the optically most efficient and cheapest way to keep a light column in line pre- and post-prism travel,
would be a Porro prism pair [preferably the lesser offset Type II (?) ] combined with a rhomboid prism *
As you know, a rhomboid displaces a light column without altering its orientation, and that could be the first prism shown in the image (?)
- - - -
By way of illustration:
From: Rhomboid Prisms | Edmund Optics
So imagine the lower image on its side in front of this Porro Type II prism:
* Using Porro prisms would have avoided the issues of: non phase coated roof prisms; non-TIR surfaces, and;
dual function surfaces with their conflicting coating needs. Additionally, Porro prisms have more relaxed demands in terms of grinding precision.
And in terms of prism numbers, Porro Type II prisms can be fabricated in various ways, with the parts then cemented together
resulting in three, two or one piece prism assemblies.
John
p.s. A Porro and rhomboid prism combination is used in the Zeiss 20x60 S mechanically image stabilised binocular.
But the rhomboid prisms are behind the main prisms, and located within the eyepieces that swivel to provide IPD adjustment.
See the image from Henry in post #11 at: High end porro's
(For more on the Zeiss 20x60 S see: Roger Vine's Zeiss 20x60S review )
Last edited:
kimmik
Well-known member
Here are some crops of areas of interest.
Henry you nailed the Optolyth, 30x60, with the smaller eyepiece. The prism is a porro with a rhomboid prism to center the image, as John has described. I did take apart a 30x80 optolyth for cleaning and they seem to have the same prisms.
And Noctivid 8x42 is correct too! In the comparison with Leica cutaway image, shows the subtle difference in eyepiece, as the xray is of the 8x42 variant.
Squinting required to make out the 4 optolyth eyepiece elements, seems to be three crowns and one flint.
Henry you nailed the Optolyth, 30x60, with the smaller eyepiece. The prism is a porro with a rhomboid prism to center the image, as John has described. I did take apart a 30x80 optolyth for cleaning and they seem to have the same prisms.
And Noctivid 8x42 is correct too! In the comparison with Leica cutaway image, shows the subtle difference in eyepiece, as the xray is of the 8x42 variant.
Squinting required to make out the 4 optolyth eyepiece elements, seems to be three crowns and one flint.
Similar threads
