Types of eyepieces?

[notFritzArgelander]

Now I'm curious. How does the F-ratio affect?

A simple way to think of it is that the focus of the telescope is where the rays converge. Those converging rays make a cone of a certain angular width. The faster the scope, the larger the angle of the cone of converging rays. An eyepiece designer has to make a design that "accepts" that cone without distorting it. Thus the minimum accepted f ratio (maximum incident cone angle) is a design requirement. It also affects how fancy the math has to be to accurately do a ray tracing diagram for the design. The larger the incident cone angle happens to be, the more complex the math. It turns out that the Plossl design works well at fast f ratios and fat cone angles.

If the ep works well at the fastest f ratio it will also work well at slower ones. But the fastest f ratio is where the design can no longer handle the incoming cone of rays without distorting the image some way.

That explains the higher requirements of eyepieces for faster scopes.
It's just a bit rough to study optics for a year or two to be able to select working eyepieces.
Also, I guess the different glass materials that are used, bring in their own features (refractive index in different wave lengths).
The (basic) geometry of the optics may not be so hard, but going through all the structures and materials used in them...
And if it was easy, nobody would pay the designers...

Yes, optics is a very technical topic. The only shortcut is to rely on sensible folks who know their stuff both from a practical and a first principles POV. Environmental regulations have changed the materials that are used also. As a schoolboy I built my own scope and in college I was an astronomy/physics major with a nice optics lab to play with. JG and Lady Fraktor also seem to me to know their stuff. JG has made a living from it I think, IIRC.

[turboscrew]

A simple way to think of it is that the focus of the telescope is where the rays converge. Those converging rays make a cone of a certain angular width. The faster the scope, the larger the angle of the cone of converging rays. An eyepiece designer has to make a design that "accepts" that cone without distorting it. Thus the minimum accepted f ratio (maximum incident cone angle) is a design requirement. It also affects how fancy the math has to be to accurately do a ray tracing diagram for the design. The larger the incident cone angle happens to be, the more complex the math. It turns out that the Plossl design works well at fast f ratios and fat cone angles.

If the ep works well at the fastest f ratio it will also work well at slower ones. But the fastest f ratio is where the design can no longer handle the incoming cone of rays without distorting the image some way.

That explains the higher requirements of eyepieces for faster scopes.
It's just a bit rough to study optics for a year or two to be able to select working eyepieces.
Also, I guess the different glass materials that are used, bring in their own features (refractive index in different wave lengths).
The (basic) geometry of the optics may not be so hard, but going through all the structures and materials used in them...
And if it was easy, nobody would pay the designers...

Yes, optics is a very technical topic. The only shortcut is to rely on sensible folks who know their stuff both from a practical and a first principles POV.

...and learn by the side...

Environmental regulations have changed the materials that are used also. As a schoolboy I built my own scope and in college I was an astronomy/physics major with a nice optics lab to play with. JG and Lady Fraktor also seem to me to know their stuff. JG has made a living from it I think, IIRC.

I have noticed, that Lady Fraktor knows about a lot about astronomy, and you seem to know about physics in general.

I've been all over the place. Even in technical university my friends considered me to be a bit odd, because I wasn't all about quick arrival to well paid job, but I actually wanted to learn and understand.

[notFritzArgelander]

That explains the higher requirements of eyepieces for faster scopes.
It's just a bit rough to study optics for a year or two to be able to select working eyepieces.
Also, I guess the different glass materials that are used, bring in their own features (refractive index in different wave lengths).
The (basic) geometry of the optics may not be so hard, but going through all the structures and materials used in them...
And if it was easy, nobody would pay the designers...

Yes, optics is a very technical topic. The only shortcut is to rely on sensible folks who know their stuff both from a practical and a first principles POV.

...and learn by the side...

Environmental regulations have changed the materials that are used also. As a schoolboy I built my own scope and in college I was an astronomy/physics major with a nice optics lab to play with. JG and Lady Fraktor also seem to me to know their stuff. JG has made a living from it I think, IIRC.

I have noticed, that Lady Fraktor knows about a lot about astronomy, and you seem to know about physics in general.

I've been all over the place. Even in technical university my friends considered me to be a bit odd, because I wasn't all about quick arrival to well paid job, but I actually wanted to learn and understand.

I went to grad school in physics after an undergrad astronomy program where I was criticized for my attitude: "You do know that the Natural Philosopher has been obsolete for over a century, don't you?"

My response was "Maybe it's time for a revival". It was not deemed adequate or congenial.

[turboscrew]

Yes, optics is a very technical topic. The only shortcut is to rely on sensible folks who know their stuff both from a practical and a first principles POV.

...and learn by the side...

Environmental regulations have changed the materials that are used also. As a schoolboy I built my own scope and in college I was an astronomy/physics major with a nice optics lab to play with. JG and Lady Fraktor also seem to me to know their stuff. JG has made a living from it I think, IIRC.

I have noticed, that Lady Fraktor knows about a lot about astronomy, and you seem to know about physics in general.

I've been all over the place. Even in technical university my friends considered me to be a bit odd, because I wasn't all about quick arrival to well paid job, but I actually wanted to learn and understand.

I went to grad school in physics after an undergrad astronomy program where I was criticized for my attitude: "You do know that the Natural Philosopher has been obsolete for over a century, don't you?"

My response was "Maybe it's time for a revival". It was not deemed adequate or congenial.

Well, I was the guy walking around corridors asking people "what is Laplace transformation". I was almos always told how much it is (the formula). Then in the basic course of functional analysis it became clear to me: It's just a complex dot product parametrized over the whole function space, where the base functions are, not sines and cosines (Fourier), but sines and cosines with growing amplitudes. That allows signals to start and end. Some people wondered, though, what did a SW engineer do in the course of functional analysis...

[notFritzArgelander]

...and learn by the side...

I have noticed, that Lady Fraktor knows about a lot about astronomy, and you seem to know about physics in general.

I've been all over the place. Even in technical university my friends considered me to be a bit odd, because I wasn't all about quick arrival to well paid job, but I actually wanted to learn and understand.

I went to grad school in physics after an undergrad astronomy program where I was criticized for my attitude: "You do know that the Natural Philosopher has been obsolete for over a century, don't you?"

My response was "Maybe it's time for a revival". It was not deemed adequate or congenial.

Well, I was the guy walking around corridors asking people "what is Laplace transformation". I was almos always told how much it is (the formula). Then in the basic course of functional analysis it became clear to me: It's just a complex dot product parametrized over the whole function space, where the base functions are, not sines and cosines (Fourier), but sines and cosines with growing amplitudes. That allows signals to start and end. Some people wondered, though, what did a SW engineer do in the course of functional analysis...

It was always a source of pleasure to me, how much functional analysis can be brought in under the roof of the inner product.

[turboscrew]

I went to grad school in physics after an undergrad astronomy program where I was criticized for my attitude: "You do know that the Natural Philosopher has been obsolete for over a century, don't you?"

My response was "Maybe it's time for a revival". It was not deemed adequate or congenial.

Well, I was the guy walking around corridors asking people "what is Laplace transformation". I was almos always told how much it is (the formula). Then in the basic course of functional analysis it became clear to me: It's just a complex dot product parametrized over the whole function space, where the base functions are, not sines and cosines (Fourier), but sines and cosines with growing amplitudes. That allows signals to start and end. Some people wondered, though, what did a SW engineer do in the course of functional analysis...

It was always a source of pleasure to me, how much functional analysis can be brought in under the roof of the inner product.

BTW, the same course made me understand what the mathematical idea of dimension is. And also what the mathematical idea of orthogonality is.

[notFritzArgelander]

But we are digressing way down the primrose path of memory lane.

[turboscrew]

Yes.
But to return to the original topic, I wonder if Baader Hyperions are OK? I've heard that Baader Morpheus is? But do those have too many lenses? Also Vixen SLVs are said to be good.
I was thinking of trying this https://www.astroshop.eu/eyepieces/baad ... mm/p,33613
and this (with and without 3xBarlow): https://www.astroshop.eu/eyepieces/tele ... ce/p,15878
Thoughts?
The problem is that in 6 mm, the price jumps from that Plössl (63€) to 421€ (TeleVue Delos) and then 704€ (TeleVue Ethos).
COVID seems to have pruned the middle-class away.

[notFritzArgelander]

I used to have the complete set of Baader Hyperions. This included the 31mm and 36mm aspheric units were the best performers of the lot. I found the shorter focal lengths unsatisfactory compared to TV Panoptic and Delos so I sold off the Hyperions and kept the TVs. The field stop was fuzzy and the 24mm was the poorest of the lot. They were 'OK'.

Now the Baader Classic Orthos are superb! They render internal detail on faint fuzzies best and for planetary are equalled or surpassed only by the KK Fujiyama Orthoscopics. They are a bit better than Delos because less glass. I've bought 3 complete sets including the 2.25 Barlow and Q-turret.

Why 3? Binoviewing for me and a set for my grandson. I can't recommend them strongly enough. They are better on faint fuzzies than TV Plossls for internal details. The TV Plossls give a marginally brighter image and may be a little better at finding the full extent of a nebula.

[turboscrew]

I used to have the complete set of Baader Hyperions. This included the 31mm and 36mm aspheric units were the best performers of the lot. I found the shorter focal lengths unsatisfactory compared to TV Panoptic and Delos so I sold off the Hyperions and kept the TVs. The field stop was fuzzy and the 24mm was the poorest of the lot. They were 'OK'.

Now the Baader Classic Orthos are superb! They render internal detail on faint fuzzies best and for planetary are equalled or surpassed only by the KK Fujiyama Orthoscopics. They are a bit better than Delos because less glass. I've bought 3 complete sets including the 2.25 Barlow and Q-turret.

Why 3? Binoviewing for me and a set for my grandson. I can't recommend them strongly enough. They are better on faint fuzzies than TV Plossls for internal details. The TV Plossls give a marginally brighter image and may be a little better at finding the full extent of a nebula.

Thanks! Order sent.