An 80 mm APO (f/6, f'/5) or 5" to 6" SCT?
😨
An 80 mm APO (f/6, f'/5) or 5" to 6" SCT?
?
On Wed, 14 Sep 2022 11:30:09 -0700 (PDT),
wrote:
An 80 mm APO (f/6, f'/5) or 5" to 6" SCT?
?
Better for what?
On Wednesday, September 14, 2022 at 2:30:49 PM UTC-7, Chris L Peterson wrote:
On Wed, 14 Sep 2022 11:30:09 -0700 (PDT),
wrote:
An 80 mm APO (f/6, f'/5) or 5" to 6" SCT?
?
Better for what?All around, of course!
Me like APOs, though!
On Wednesday, September 14, 2022 at 2:30:49 PM UTC-7, Chris L Peterson wrote: >> On Wed, 14 Sep 2022 11:30:09 -0700 (PDT),
wrote:
An 80 mm APO (f/6, f'/5) or 5" to 6" SCT?
?
Better for what?
All around, of course!
On Wednesday, September 14, 2022 at 6:20:21 PM UTC-4, StarDust wrote:
On Wednesday, September 14, 2022 at 2:30:49 PM UTC-7, Chris L Peterson wrote:
On Wed, 14 Sep 2022 11:30:09 -0700 (PDT),
wrote:
An 80 mm APO (f/6, f'/5) or 5" to 6" SCT?
?
Both of those telescopes are good "all-around" performers.Better for what?All around, of course!
Me like APOs, though!
The telescopes to avoid are those 'schiefspiegler' types.
The telescopes to avoid are those 'schiefspiegler' types.
On Thursday, September 15, 2022 at 4:55:33 AM UTC-7, W wrote:in their limited application, they are quite good.
The telescopes to avoid are those 'schiefspiegler' types.Why do you make this claim? Sure, a Schiefspiegler design is an exotic design and is best suited to lunar and planetary observations... but for folks who enjoy such observations, they are really good. For general observation, not so much... but still,
On Thursday, September 15, 2022 at 10:36:16 PM UTC-4, palsing wrote:in their limited application, they are quite good.
On Thursday, September 15, 2022 at 4:55:33 AM UTC-7, W wrote:
The telescopes to avoid are those 'schiefspiegler' types.Why do you make this claim? Sure, a Schiefspiegler design is an exotic design and is best suited to lunar and planetary observations... but for folks who enjoy such observations, they are really good. For general observation, not so much... but still,
It's not a claim, it's a fact. All one needs to do to get a better image of a planet is to get a slightly larger telescope of conventional, normal design.
On Thu, 15 Sep 2022 19:45:52 -0700 (PDT), W <wsne...@hotmail.com>still, in their limited application, they are quite good.
wrote:
On Thursday, September 15, 2022 at 10:36:16 PM UTC-4, palsing wrote:
On Thursday, September 15, 2022 at 4:55:33 AM UTC-7, W wrote:
The telescopes to avoid are those 'schiefspiegler' types.Why do you make this claim? Sure, a Schiefspiegler design is an exotic design and is best suited to lunar and planetary observations... but for folks who enjoy such observations, they are really good. For general observation, not so much... but
It's not a claim, it's a fact. All one needs to do to get a better image of a planet is to get a slightly larger telescope of conventional, normal design.Image with a camera, yes. Visual image through an eyepiece. Nope.
Obstructed apertures present no problem for imagers. They are
problematic for visual planet observation.
On Thursday, September 15, 2022 at 4:55:33 AM UTC-7, W wrote:
On Wednesday, September 14, 2022 at 6:20:21 PM UTC-4, StarDust wrote:
On Wednesday, September 14, 2022 at 2:30:49 PM UTC-7, Chris L Peterson wrote:
On Wed, 14 Sep 2022 11:30:09 -0700 (PDT),
wrote:
An 80 mm APO (f/6, f'/5) or 5" to 6" SCT?
?
Both of those telescopes are good "all-around" performers.Better for what?All around, of course!
Me like APOs, though!
The telescopes to avoid are those 'schiefspiegler' types.Can't pronounce it, so I don't buy it!
On Friday, September 16, 2022 at 12:07:43 AM UTC-4, Chris L Peterson wrote:still, in their limited application, they are quite good.
On Thu, 15 Sep 2022 19:45:52 -0700 (PDT), W <wsne...@hotmail.com>
wrote:
On Thursday, September 15, 2022 at 10:36:16 PM UTC-4, palsing wrote:
On Thursday, September 15, 2022 at 4:55:33 AM UTC-7, W wrote:
The telescopes to avoid are those 'schiefspiegler' types.Why do you make this claim? Sure, a Schiefspiegler design is an exotic design and is best suited to lunar and planetary observations... but for folks who enjoy such observations, they are really good. For general observation, not so much... but
Image with a camera, yes. Visual image through an eyepiece. Nope.
It's not a claim, it's a fact. All one needs to do to get a better image of a planet is to get a slightly larger telescope of conventional, normal design.
Obstructed apertures present no problem for imagers. They are
problematic for visual planet observation.
Perhaps you would like to explain how the greater light-gathering power and higher resolving power of a larger telescope is "problematic for visual planet observation?"
On Fri, 16 Sep 2022 01:52:49 -0700 (PDT), W <wsne...@hotmail.com>still, in their limited application, they are quite good.
wrote:
On Friday, September 16, 2022 at 12:07:43 AM UTC-4, Chris L Peterson wrote: >> On Thu, 15 Sep 2022 19:45:52 -0700 (PDT), W <wsne...@hotmail.com>
wrote:
On Thursday, September 15, 2022 at 10:36:16 PM UTC-4, palsing wrote:
On Thursday, September 15, 2022 at 4:55:33 AM UTC-7, W wrote:
The telescopes to avoid are those 'schiefspiegler' types.Why do you make this claim? Sure, a Schiefspiegler design is an exotic design and is best suited to lunar and planetary observations... but for folks who enjoy such observations, they are really good. For general observation, not so much... but
Image with a camera, yes. Visual image through an eyepiece. Nope.
It's not a claim, it's a fact. All one needs to do to get a better image of a planet is to get a slightly larger telescope of conventional, normal design.
Obstructed apertures present no problem for imagers. They are
problematic for visual planet observation.
Perhaps you would like to explain how the greater light-gathering power and higher resolving power of a larger telescope is "problematic for visual planet observation?"
Perhaps you should investigate the meaning of the MTF in optics.
On Friday, September 16, 2022 at 9:27:24 AM UTC-4, Chris L Peterson wrote:still, in their limited application, they are quite good.
On Fri, 16 Sep 2022 01:52:49 -0700 (PDT), W <wsne...@hotmail.com>
wrote:
On Friday, September 16, 2022 at 12:07:43 AM UTC-4, Chris L Peterson wrote: >> >> On Thu, 15 Sep 2022 19:45:52 -0700 (PDT), W <wsne...@hotmail.com>
wrote:
On Thursday, September 15, 2022 at 10:36:16 PM UTC-4, palsing wrote:
On Thursday, September 15, 2022 at 4:55:33 AM UTC-7, W wrote:
The telescopes to avoid are those 'schiefspiegler' types.Why do you make this claim? Sure, a Schiefspiegler design is an exotic design and is best suited to lunar and planetary observations... but for folks who enjoy such observations, they are really good. For general observation, not so much... but
Image with a camera, yes. Visual image through an eyepiece. Nope.
It's not a claim, it's a fact. All one needs to do to get a better image of a planet is to get a slightly larger telescope of conventional, normal design.
Obstructed apertures present no problem for imagers. They are
problematic for visual planet observation.
Perhaps you would like to explain how the greater light-gathering power and higher resolving power of a larger telescope is "problematic for visual planet observation?"
Perhaps you should investigate the meaning of the MTF in optics.
Perhaps you should learn something about optics? You certainly don't seem to know much about MTF!
Now, try to ANSWER the question truthfully and without any more of your usual BS:
"Perhaps you would like to explain how the greater light-gathering power and higher resolving power of a larger telescope is 'problematic for visual planet observation?' "
On Friday, September 16, 2022 at 10:48:57 AM UTC-4, Chris L Peterson wrote:but still, in their limited application, they are quite good.
On Fri, 16 Sep 2022 07:01:57 -0700 (PDT), W <wsne...@hotmail.com>
wrote:
On Friday, September 16, 2022 at 9:27:24 AM UTC-4, Chris L Peterson wrote: >> >> On Fri, 16 Sep 2022 01:52:49 -0700 (PDT), W <wsne...@hotmail.com>
wrote:
On Friday, September 16, 2022 at 12:07:43 AM UTC-4, Chris L Peterson wrote:
On Thu, 15 Sep 2022 19:45:52 -0700 (PDT), W <wsne...@hotmail.com>
wrote:
On Thursday, September 15, 2022 at 10:36:16 PM UTC-4, palsing wrote: >> >> >> >> On Thursday, September 15, 2022 at 4:55:33 AM UTC-7, W wrote:
The telescopes to avoid are those 'schiefspiegler' types.Why do you make this claim? Sure, a Schiefspiegler design is an exotic design and is best suited to lunar and planetary observations... but for folks who enjoy such observations, they are really good. For general observation, not so much...
I just did.Image with a camera, yes. Visual image through an eyepiece. Nope.
It's not a claim, it's a fact. All one needs to do to get a better image of a planet is to get a slightly larger telescope of conventional, normal design.
Obstructed apertures present no problem for imagers. They are
problematic for visual planet observation.
Perhaps you would like to explain how the greater light-gathering power and higher resolving power of a larger telescope is "problematic for visual planet observation?"
Perhaps you should investigate the meaning of the MTF in optics.
Perhaps you should learn something about optics? You certainly don't seem to know much about MTF!
Now, try to ANSWER the question truthfully and without any more of your usual BS:
"Perhaps you would like to explain how the greater light-gathering power and higher resolving power of a larger telescope is 'problematic for visual planet observation?' "
You did not answer the question. That's twice that you have evaded it.
On Fri, 16 Sep 2022 07:01:57 -0700 (PDT), W <wsne...@hotmail.com>but still, in their limited application, they are quite good.
wrote:
On Friday, September 16, 2022 at 9:27:24 AM UTC-4, Chris L Peterson wrote: >> On Fri, 16 Sep 2022 01:52:49 -0700 (PDT), W <wsne...@hotmail.com>
wrote:
On Friday, September 16, 2022 at 12:07:43 AM UTC-4, Chris L Peterson wrote:
On Thu, 15 Sep 2022 19:45:52 -0700 (PDT), W <wsne...@hotmail.com>
wrote:
On Thursday, September 15, 2022 at 10:36:16 PM UTC-4, palsing wrote: >> >> >> On Thursday, September 15, 2022 at 4:55:33 AM UTC-7, W wrote:
The telescopes to avoid are those 'schiefspiegler' types.Why do you make this claim? Sure, a Schiefspiegler design is an exotic design and is best suited to lunar and planetary observations... but for folks who enjoy such observations, they are really good. For general observation, not so much...
Image with a camera, yes. Visual image through an eyepiece. Nope.
It's not a claim, it's a fact. All one needs to do to get a better image of a planet is to get a slightly larger telescope of conventional, normal design.
Obstructed apertures present no problem for imagers. They are
problematic for visual planet observation.
Perhaps you would like to explain how the greater light-gathering power and higher resolving power of a larger telescope is "problematic for visual planet observation?"
Perhaps you should investigate the meaning of the MTF in optics.
Perhaps you should learn something about optics? You certainly don't seem to know much about MTF!
Now, try to ANSWER the question truthfully and without any more of your usual BS:
"Perhaps you would like to explain how the greater light-gathering power and higher resolving power of a larger telescope is 'problematic for visual planet observation?' "I just did.
On Fri, 16 Sep 2022 09:51:10 -0700 (PDT), W <wsne...@hotmail.com>but still, in their limited application, they are quite good.
wrote:
On Friday, September 16, 2022 at 10:48:57 AM UTC-4, Chris L Peterson wrote: >> On Fri, 16 Sep 2022 07:01:57 -0700 (PDT), W <wsne...@hotmail.com>
wrote:
On Friday, September 16, 2022 at 9:27:24 AM UTC-4, Chris L Peterson wrote:
On Fri, 16 Sep 2022 01:52:49 -0700 (PDT), W <wsne...@hotmail.com>
wrote:
On Friday, September 16, 2022 at 12:07:43 AM UTC-4, Chris L Peterson wrote:
On Thu, 15 Sep 2022 19:45:52 -0700 (PDT), W <wsne...@hotmail.com> >> >> >> wrote:
On Thursday, September 15, 2022 at 10:36:16 PM UTC-4, palsing wrote:
On Thursday, September 15, 2022 at 4:55:33 AM UTC-7, W wrote:
The telescopes to avoid are those 'schiefspiegler' types.Why do you make this claim? Sure, a Schiefspiegler design is an exotic design and is best suited to lunar and planetary observations... but for folks who enjoy such observations, they are really good. For general observation, not so much...
I just did.Image with a camera, yes. Visual image through an eyepiece. Nope. >> >> >> Obstructed apertures present no problem for imagers. They are
It's not a claim, it's a fact. All one needs to do to get a better image of a planet is to get a slightly larger telescope of conventional, normal design.
problematic for visual planet observation.
Perhaps you would like to explain how the greater light-gathering power and higher resolving power of a larger telescope is "problematic for visual planet observation?"
Perhaps you should investigate the meaning of the MTF in optics.
Perhaps you should learn something about optics? You certainly don't seem to know much about MTF!
Now, try to ANSWER the question truthfully and without any more of your usual BS:
"Perhaps you would like to explain how the greater light-gathering power and higher resolving power of a larger telescope is 'problematic for visual planet observation?' "
You did not answer the question. That's twice that you have evaded it.My, aren't you stupid. I did answer it. A central obstruction reduces contrast. If you think that isn't a problem for a planetary observer,
you're as stupid as you are illiterate.
On Friday, September 16, 2022 at 1:12:37 PM UTC-4, Chris L Peterson wrote:but still, in their limited application, they are quite good.
On Fri, 16 Sep 2022 09:51:10 -0700 (PDT), W <wsne...@hotmail.com>
wrote:
On Friday, September 16, 2022 at 10:48:57 AM UTC-4, Chris L Peterson wrote: >> >> On Fri, 16 Sep 2022 07:01:57 -0700 (PDT), W <wsne...@hotmail.com>
wrote:
On Friday, September 16, 2022 at 9:27:24 AM UTC-4, Chris L Peterson wrote:
On Fri, 16 Sep 2022 01:52:49 -0700 (PDT), W <wsne...@hotmail.com>
wrote:
On Friday, September 16, 2022 at 12:07:43 AM UTC-4, Chris L Peterson wrote:
On Thu, 15 Sep 2022 19:45:52 -0700 (PDT), W <wsne...@hotmail.com> >> >> >> >> wrote:
On Thursday, September 15, 2022 at 10:36:16 PM UTC-4, palsing wrote:
On Thursday, September 15, 2022 at 4:55:33 AM UTC-7, W wrote:
The telescopes to avoid are those 'schiefspiegler' types.Why do you make this claim? Sure, a Schiefspiegler design is an exotic design and is best suited to lunar and planetary observations... but for folks who enjoy such observations, they are really good. For general observation, not so much...
My, aren't you stupid. I did answer it. A central obstruction reducesI just did.Image with a camera, yes. Visual image through an eyepiece. Nope. >> >> >> >> Obstructed apertures present no problem for imagers. They are
It's not a claim, it's a fact. All one needs to do to get a better image of a planet is to get a slightly larger telescope of conventional, normal design.
problematic for visual planet observation.
Perhaps you would like to explain how the greater light-gathering power and higher resolving power of a larger telescope is "problematic for visual planet observation?"
Perhaps you should investigate the meaning of the MTF in optics.
Perhaps you should learn something about optics? You certainly don't seem to know much about MTF!
Now, try to ANSWER the question truthfully and without any more of your usual BS:
"Perhaps you would like to explain how the greater light-gathering power and higher resolving power of a larger telescope is 'problematic for visual planet observation?' "
You did not answer the question. That's twice that you have evaded it.
contrast. If you think that isn't a problem for a planetary observer,
you're as stupid as you are illiterate.
I never mentioned "central obstruction" at all. Perhaps you have a central obstruction in your brain?
What part of this question do you NOT understand? :
"Perhaps you would like to explain how the greater light-gathering power and higher resolving power of a larger telescope is 'problematic for visual planet observation?' "
On Friday, September 16, 2022 at 1:12:37 PM UTC-4, Chris L Peterson wrote:
My, aren't you stupid. I did answer it. A central obstruction reduces contrast. If you think that isn't a problem for a planetary observer, you're as stupid as you are illiterate.
I never mentioned "central obstruction" at all. Perhaps you have a central obstruction in your brain?
What part of this question do you NOT understand? :
"Perhaps you would like to explain how the greater light-gathering power and higher resolving power of a larger telescope is 'problematic for visual planet observation?' "
On Friday, September 16, 2022 at 12:07:43 AM UTC-4, Chris L Peterson wrote:
Image with a camera, yes. Visual image through an eyepiece. Nope. Obstructed apertures present no problem for imagers. They are
problematic for visual planet observation.
Perhaps you would like to explain how the greater light-gathering power and higher resolving power of a larger telescope is "problematic for visual planet observation?"
On Thursday, September 15, 2022 at 8:57:16 PM UTC-6, StarDust wrote:
Can't pronounce it, so I don't buy it!A Schiefspiegler is a reflecting telescope with no
central obstruction.
No central obstruction. No chromatic aberration. What's
not to like?
Well, for one thing, usually Schiefspiegler designs have
long focal lengths for their apertures. So they're more
like refractors than like Dobsonians, good for planets,
but not for the deep sky.
For another, while I think Orion actually did make and
sell one, in general, you don't go and buy one of these,
you have to make it yourself.
And, because it's an off-axis design, it's very sensitive
to errors in alignment, and there are other aberrations
it will have - and they won't be symmetrical.
John Savard
On Fri, 16 Sep 2022 11:21:44 -0700 (PDT), W <wsne...@hotmail.com>.. but still, in their limited application, they are quite good.
wrote:
On Friday, September 16, 2022 at 1:12:37 PM UTC-4, Chris L Peterson wrote: >> On Fri, 16 Sep 2022 09:51:10 -0700 (PDT), W <wsne...@hotmail.com>
wrote:
On Friday, September 16, 2022 at 10:48:57 AM UTC-4, Chris L Peterson wrote:
On Fri, 16 Sep 2022 07:01:57 -0700 (PDT), W <wsne...@hotmail.com>
wrote:
On Friday, September 16, 2022 at 9:27:24 AM UTC-4, Chris L Peterson wrote:
On Fri, 16 Sep 2022 01:52:49 -0700 (PDT), W <wsne...@hotmail.com> >> >> >> wrote:
On Friday, September 16, 2022 at 12:07:43 AM UTC-4, Chris L Peterson wrote:
On Thu, 15 Sep 2022 19:45:52 -0700 (PDT), W <wsne...@hotmail.com>
wrote:
On Thursday, September 15, 2022 at 10:36:16 PM UTC-4, palsing wrote:
On Thursday, September 15, 2022 at 4:55:33 AM UTC-7, W wrote: >> >> >> >> >>
The telescopes to avoid are those 'schiefspiegler' types. >> >> >> >> >> Why do you make this claim? Sure, a Schiefspiegler design is an exotic design and is best suited to lunar and planetary observations... but for folks who enjoy such observations, they are really good. For general observation, not so much.
contrast. If you think that isn't a problem for a planetary observer,I just did.Image with a camera, yes. Visual image through an eyepiece. Nope.
It's not a claim, it's a fact. All one needs to do to get a better image of a planet is to get a slightly larger telescope of conventional, normal design.
Obstructed apertures present no problem for imagers. They are
problematic for visual planet observation.
Perhaps you would like to explain how the greater light-gathering power and higher resolving power of a larger telescope is "problematic for visual planet observation?"
Perhaps you should investigate the meaning of the MTF in optics.
Perhaps you should learn something about optics? You certainly don't seem to know much about MTF!
Now, try to ANSWER the question truthfully and without any more of your usual BS:
"Perhaps you would like to explain how the greater light-gathering power and higher resolving power of a larger telescope is 'problematic for visual planet observation?' "
You did not answer the question. That's twice that you have evaded it. >> My, aren't you stupid. I did answer it. A central obstruction reduces
you're as stupid as you are illiterate.
I never mentioned "central obstruction" at all. Perhaps you have a central obstruction in your brain?
What part of this question do you NOT understand? :
"Perhaps you would like to explain how the greater light-gathering power and higher resolving power of a larger telescope is 'problematic for visual planet observation?' "Go fuck yourself.
Can't pronounce it, so I don't buy it!
On Thursday, September 15, 2022 at 8:57:16 PM UTC-6, StarDust wrote:
Can't pronounce it, so I don't buy it!A Schiefspiegler is a reflecting telescope with no
central obstruction.
No central obstruction. No chromatic aberration. What's
not to like?
Well, for one thing, usually Schiefspiegler designs have
long focal lengths for their apertures. So they're more
like refractors than like Dobsonians, good for planets,
but not for the deep sky.
For another, while I think Orion actually did make and
sell one, in general, you don't go and buy one of these,
you have to make it yourself.
And, because it's an off-axis design, it's very sensitive
to errors in alignment, and there are other aberrations
it will have - and they won't be symmetrical.
On Friday, September 16, 2022 at 2:52:51 AM UTC-6, W wrote:
On Friday, September 16, 2022 at 12:07:43 AM UTC-4, Chris L Peterson wrote:
Image with a camera, yes. Visual image through an eyepiece. Nope. Obstructed apertures present no problem for imagers. They are
problematic for visual planet observation.
Perhaps you would like to explain how the greater light-gathering power and higher resolving power of a larger telescope is "problematic for visual planet observation?"He did not claim that greater light-gathering power or higher resolving power were problematic.
The central obstruction of a Schmidt-Cassegrain telescope, however, which he did
refer to, and indeed which was the issue, given that an apochromat and a Schmidt-Cassegrain
were being compared, _is_ problematic.
"Obstructed apertures present no problem for imagers. They are problematic for
visual planet observation."
See? He said that what was problematic was the fact that the aperture was obstructed. So by explaining that this was what he was referring to, he did explain himself. I don't know why you were claiming otherwise.
On Friday, September 16, 2022 at 12:21:45 PM UTC-6, W wrote:
On Friday, September 16, 2022 at 1:12:37 PM UTC-4, Chris L Peterson wrote:
My, aren't you stupid. I did answer it. A central obstruction reduces contrast. If you think that isn't a problem for a planetary observer, you're as stupid as you are illiterate.
I never mentioned "central obstruction" at all. Perhaps you have a central obstruction in your brain?
What part of this question do you NOT understand? :
"Perhaps you would like to explain how the greater light-gathering power and higher resolving power of a larger telescope is 'problematic for visual planet observation?' "Well, you asked that question *immediately following* a statement on
his part that *central obstruction* was problematic. He did NOT make
a statement that greater light-gathering power and higher resolving
power in themselves were problematic, and therefore he had no obligation
to explain or justify such a ludicrous position as you were imputing to him.
It was entirely natural to assume your question was intended to ask
him to explain *his statement* as he made it, not confined to the
specific issues which you repeated in your question.
On Friday, September 16, 2022 at 3:54:29 PM UTC-4, Quadibloc wrote:day.
On Thursday, September 15, 2022 at 8:57:16 PM UTC-6, StarDust wrote:
Can't pronounce it, so I don't buy it!A Schiefspiegler is a reflecting telescope with no
central obstruction.
No central obstruction. No chromatic aberration. What's
not to like?
Well, for one thing, usually Schiefspiegler designs have
long focal lengths for their apertures. So they're more
like refractors than like Dobsonians, good for planets,
but not for the deep sky.
For another, while I think Orion actually did make and
sell one, in general, you don't go and buy one of these,
you have to make it yourself.
And, because it's an off-axis design, it's very sensitiveThe "first, original" version of these pigs was the two-mirror, 4.25-inch f/26 (?) monstrosity that appeared sometime in the 1950s. It was thought to be a poor-man's 4-inch refractor, a size which was probably beyond the means of many amateurs of the
to errors in alignment, and there are other aberrations
it will have - and they won't be symmetrical.
What its makers failed to notice is that a good six-inch Newt (f8 or so) could do as much and a lot more besides.
These things became ever more outlandish over the years.
If these were in demand then there would be companies falling all over themselves trying to make them. But we never see that happening.
On Friday, September 16, 2022 at 12:21:45 PM UTC-6, W wrote:
On Friday, September 16, 2022 at 1:12:37 PM UTC-4, Chris L Peterson wrote:
My, aren't you stupid. I did answer it. A central obstruction reduces
contrast. If you think that isn't a problem for a planetary observer,
you're as stupid as you are illiterate.
I never mentioned "central obstruction" at all. Perhaps you have a central obstruction in your brain?
What part of this question do you NOT understand? :
"Perhaps you would like to explain how the greater light-gathering power and higher resolving power of a larger telescope is 'problematic for visual planet observation?' "
Well, you asked that question *immediately following* a statement on
his part that *central obstruction* was problematic. He did NOT make
a statement that greater light-gathering power and higher resolving
power in themselves were problematic, and therefore he had no obligation
to explain or justify such a ludicrous position as you were imputing to him.
It was entirely natural to assume your question was intended to ask
him to explain *his statement* as he made it, not confined to the
specific issues which you repeated in your question.
On Wed, 14 Sep 2022 11:30:09 -0700 (PDT), StarDust <cso...@gmail.com>
wrote:
An 80 mm APO (f/6, f'/5) or 5" to 6" SCT?
?
Better for what?
On Fri, 16 Sep 2022 12:51:01 -0700 (PDT), Quadibloc
<jsa...@ecn.ab.ca> wrote:
On Friday, September 16, 2022 at 12:21:45 PM UTC-6, W wrote:
On Friday, September 16, 2022 at 1:12:37 PM UTC-4, Chris L Peterson wrote:
My, aren't you stupid. I did answer it. A central obstruction reduces
contrast. If you think that isn't a problem for a planetary observer,
you're as stupid as you are illiterate.
I never mentioned "central obstruction" at all. Perhaps you have a central obstruction in your brain?
What part of this question do you NOT understand? :
"Perhaps you would like to explain how the greater light-gathering power and higher resolving power of a larger telescope is 'problematic for visual planet observation?' "
Well, you asked that question *immediately following* a statement on
his part that *central obstruction* was problematic. He did NOT make
a statement that greater light-gathering power and higher resolving
power in themselves were problematic, and therefore he had no obligation
to explain or justify such a ludicrous position as you were imputing to him.
It was entirely natural to assume your question was intended to askHe's an asshole. That pretty much explains everything he ever says.
him to explain *his statement* as he made it, not confined to the
specific issues which you repeated in your question.
On Friday, September 16, 2022 at 4:53:37 PM UTC-7, W wrote:day.
On Friday, September 16, 2022 at 3:54:29 PM UTC-4, Quadibloc wrote:
On Thursday, September 15, 2022 at 8:57:16 PM UTC-6, StarDust wrote:
Can't pronounce it, so I don't buy it!A Schiefspiegler is a reflecting telescope with no
central obstruction.
No central obstruction. No chromatic aberration. What's
not to like?
Well, for one thing, usually Schiefspiegler designs have
long focal lengths for their apertures. So they're more
like refractors than like Dobsonians, good for planets,
but not for the deep sky.
For another, while I think Orion actually did make and
sell one, in general, you don't go and buy one of these,
you have to make it yourself.
And, because it's an off-axis design, it's very sensitiveThe "first, original" version of these pigs was the two-mirror, 4.25-inch f/26 (?) monstrosity that appeared sometime in the 1950s. It was thought to be a poor-man's 4-inch refractor, a size which was probably beyond the means of many amateurs of the
to errors in alignment, and there are other aberrations
it will have - and they won't be symmetrical.
What its makers failed to notice is that a good six-inch Newt (f8 or so) could do as much and a lot more besides.
These things became ever more outlandish over the years.
If these were in demand then there would be companies falling all over themselves trying to make them. But we never see that happening.6" Dynascopes were legendary from the 50's, 60's, high quality newts, 20 waves or better over all.
Some of the mirrors were tested and they were 40 waves .
Later models from the 70's not as good!
On Friday, September 16, 2022 at 10:38:35 PM UTC-4, StarDust wrote:the day.
On Friday, September 16, 2022 at 4:53:37 PM UTC-7, W wrote:
On Friday, September 16, 2022 at 3:54:29 PM UTC-4, Quadibloc wrote:
On Thursday, September 15, 2022 at 8:57:16 PM UTC-6, StarDust wrote:
Can't pronounce it, so I don't buy it!A Schiefspiegler is a reflecting telescope with no
central obstruction.
No central obstruction. No chromatic aberration. What's
not to like?
Well, for one thing, usually Schiefspiegler designs have
long focal lengths for their apertures. So they're more
like refractors than like Dobsonians, good for planets,
but not for the deep sky.
For another, while I think Orion actually did make and
sell one, in general, you don't go and buy one of these,
you have to make it yourself.
And, because it's an off-axis design, it's very sensitiveThe "first, original" version of these pigs was the two-mirror, 4.25-inch f/26 (?) monstrosity that appeared sometime in the 1950s. It was thought to be a poor-man's 4-inch refractor, a size which was probably beyond the means of many amateurs of
to errors in alignment, and there are other aberrations
it will have - and they won't be symmetrical.
What its makers failed to notice is that a good six-inch Newt (f8 or so) could do as much and a lot more besides.
These things became ever more outlandish over the years.
The SCT had started to distort the market by the mid-70s. The BBAs were also out in force, cutting costs and making things just good enough, not necessarily excellent.If these were in demand then there would be companies falling all over themselves trying to make them. But we never see that happening.6" Dynascopes were legendary from the 50's, 60's, high quality newts, 20 waves or better over all.
Some of the mirrors were tested and they were 40 waves .
Later models from the 70's not as good!
A 20- or 40-wave mirror would be awful. 1/20-wave mirror is much better.
On Saturday, September 17, 2022 at 3:32:39 AM UTC-7, W wrote:the day.
On Friday, September 16, 2022 at 10:38:35 PM UTC-4, StarDust wrote:
On Friday, September 16, 2022 at 4:53:37 PM UTC-7, W wrote:
On Friday, September 16, 2022 at 3:54:29 PM UTC-4, Quadibloc wrote:
On Thursday, September 15, 2022 at 8:57:16 PM UTC-6, StarDust wrote:
Can't pronounce it, so I don't buy it!A Schiefspiegler is a reflecting telescope with no
central obstruction.
No central obstruction. No chromatic aberration. What's
not to like?
Well, for one thing, usually Schiefspiegler designs have
long focal lengths for their apertures. So they're more
like refractors than like Dobsonians, good for planets,
but not for the deep sky.
For another, while I think Orion actually did make and
sell one, in general, you don't go and buy one of these,
you have to make it yourself.
And, because it's an off-axis design, it's very sensitiveThe "first, original" version of these pigs was the two-mirror, 4.25-inch f/26 (?) monstrosity that appeared sometime in the 1950s. It was thought to be a poor-man's 4-inch refractor, a size which was probably beyond the means of many amateurs of
to errors in alignment, and there are other aberrations
it will have - and they won't be symmetrical.
What its makers failed to notice is that a good six-inch Newt (f8 or so) could do as much and a lot more besides.
These things became ever more outlandish over the years.
The SCT had started to distort the market by the mid-70s. The BBAs were also out in force, cutting costs and making things just good enough, not necessarily excellent.If these were in demand then there would be companies falling all over themselves trying to make them. But we never see that happening.6" Dynascopes were legendary from the 50's, 60's, high quality newts, 20 waves or better over all.
Some of the mirrors were tested and they were 40 waves .
Later models from the 70's not as good!
A 20- or 40-wave mirror would be awful. 1/20-wave mirror is much better.Why?
After the scope was put together, it was 20 wave over all.
Those old timer telescope builders really meant quality in their workmanship!
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