Post by Ron Walker on Apr 29, 2022 17:09:09 GMT -7
Posted by: Chris4488 Feb 8 2020, 11:19 PM
Does anyone have information on converting a planisphere projection to a dodecahedron?
Thanks
Chris
Posted by: Ron Walker Feb 9 2020, 09:05 AM
QUOTE(Chris4488 @ Feb 8 2020, 11:19 PM) *
Does anyone have information on converting a planisphere projection to a dodecahedron?
Thanks
Chris
Not at all sure how to do that as a planisphere tends to distort the positions of the stars as you look to the outside edge of the chart. Depending on the size, I would imagine a dodechedron could almost be plotted as a sphere. I'm thinking someone did the tipe of plotting you are requesting. I believe it is here someplace, I will look for it.
Welcome to OCP.
Posted by: Strgzr Feb 9 2020, 12:53 PM
QUOTE(Ron Walker @ Feb 9 2020, 09:05 AM) *
I believe it is here someplace, I will look for it.
Welcome to OCP.
To bad the search function is tits up!
And Welcome Chris!!
Posted by: Ken Miller Feb 9 2020, 02:48 PM
I did a dodecahedron map several years ago. It was based on some software that could plot stars on non-spherical surfaces. It was a close match for my actual Spitz A1. I have since sold the Spitz and gave the plot to the buyer. I even made a miniature Spitz dodecahedron with plots that I created with the software. The software is not readily available, and I would have to dredge through my archives to find a copy.
Ken
Posted by: Ken Miller Feb 9 2020, 03:23 PM
After doing more research, I found out that I got the software 9 years ago from someone named Charle Rupp. It looks like he had posted on this forum, but I don't know if he is still active. I found a copy of the software, and I suggest that you contact me to discuss it further. You can email me at "isotope115 at y . a . h . 0 . 0 . d0t . c. 0 . m"
Posted by: Ken Miller Feb 9 2020, 03:44 PM
Well, I researched some more and received a blow that is similar to too many others that have hit me recently. Charle passed away on January 3 of this year.
Posted by: Ron Walker Feb 9 2020, 04:40 PM
Have you reviewed this?
www.observatorycentral.com/index.php?showtopic=25472
Posted by: Ken Miller Feb 9 2020, 04:47 PM
QUOTE(Ron Walker @ Feb 9 2020, 03:40 PM) *
Have you reviewed this?
www.observatorycentral.com/index.php?showtopic=25472
Ron
That is really impressive!
Ken
Posted by: Strgzr Feb 9 2020, 04:53 PM
QUOTE(Ken Miller @ Feb 9 2020, 03:44 PM) *
Well, I researched some more and received a blow that is similar to too many others that have hit me recently. Charle passed away on January 3 of this year.
Very Sad! Rest In Peace Charle.
Posted by: Strgzr Feb 9 2020, 04:54 PM
QUOTE(Ron Walker @ Feb 9 2020, 04:40 PM) *
Have you reviewed this?
www.observatorycentral.com/index.php?showtopic=25472
Awesome!
Wish we could get an update from Philostopher! That's a Hellofa build he's got going on.
Posted by: Ron Walker Feb 10 2020, 09:57 AM
QUOTE(Strgzr @ Feb 9 2020, 04:54 PM) *
Awesome!
Wish we could get an update from Philostopher! That's a Hellofa build he's got going on.
I'm not at all sure if this idea ever panned out. Right now he is working on a single ball pinhole design which, as usual, is quite impressive.
Posted by: Ron Walker Feb 14 2020, 02:14 PM
QUOTE(Ron Walker @ Feb 10 2020, 09:57 AM) *
I'm not at all sure if this idea ever panned out. Right now he is working on a single ball pinhole design which, as usual, is quite impressive.
I talked with James and he did a lot of stuff for an optical projection but with the sky divided into 32 sections. This computer stuff is way above me so here is his email.
James Hicks
philostopher1@gmail.com
You can also reach him on his Facebook page "Planetarium Builders and Enthusiasts".
Posted by: Philostopher1 May 14 2020, 04:39 AM
QUOTE(Strgzr @ Feb 9 2020, 04:53 PM) *
Very Sad! Rest In Peace Charle.
Oh Man I am so sorry to hear this. I haven't been able to sign on for a long time. This really hurts and I have never met him.
Posted by: Philostopher1 May 14 2020, 04:49 AM
QUOTE(Chris4488 @ Feb 8 2020, 11:19 PM) *
Does anyone have information on converting a planisphere projection to a dodecahedron?
Thanks
Chris
Hey Chris,
I am going to talk to Paul Bourke and see if he can do a dodecahedron map. I think it's just a matter of plugging in the model. I am still vascillating on my optical plate projector. I was originally thinking of a Dodeca. Takayushi Ohira had a Megastar based on 12 plates.
At this point in the truncated icosahedron version, we have the 10,000=/- stars from Hipparcos mapped. If you have seen the JPGs I posted in my thread, the star magnitudes are represented as spheres. We need to figure out the scale for Sirius on a plate vs the smallest star that can be lithographed. I know Ohira was using laser lithography and getting down to 180 microns. I supect he is using step lithography. His first megastar were homemade plates using an argon laser direct write lithography I think.
Email me at Philostopher1@gmail.com
Are you in my FB group? Though this is a better forum to catalog a project and archive it.
Posted by: Ron Walker May 14 2020, 09:57 AM
QUOTE(Philostopher1 @ May 14 2020, 04:49 AM) *
Hey Chris,
I am going to talk to Paul Bourke and see if he can do a dodecahedron map. I think it's just a matter of plugging in the model. I am still vascillating on my optical plate projector. I was originally thinking of a Dodeca. Takayushi Ohira had a Megastar based on 12 plates.
At this point in the truncated icosahedron version, we have the 10,000=/- stars from Hipparcos mapped. If you have seen the JPGs I posted in my thread, the star magnitudes are represented as spheres. We need to figure out the scale for Sirius on a plate vs the smallest star that can be lithographed. I know Ohira was using laser lithography and getting down to 180 microns. I supect he is using step lithography. His first megastar were homemade plates using an argon laser direct write lithography I think.
Email me at Philostopher1@gmail.com
Are you in my FB group? Though this is a better forum to catalog a project and archive it.
I would suggest that 1st magnitude and brighter stars be projected by separate projectors. They will project as big moons if placed on a single star plate and really destroy the illusion.
Posted by: Philostopher1 May 14 2020, 11:31 PM
QUOTE(Ron Walker @ May 14 2020, 09:57 AM) *
I would suggest that 1st magnitude and brighter stars be projected by separate projectors. They will project as big moons if placed on a single star plate and really destroy the illusion.
Good point! That is how Minolta and Zeiss are doing it in the Infinium and Universarium.
Posted by: Philostopher1 May 14 2020, 11:39 PM
QUOTE(Chris4488 @ Feb 8 2020, 11:19 PM) *
Does anyone have information on converting a planisphere projection to a dodecahedron?
Thanks
Chris
I am working on this with Paul Bourke now. Are you wanting to do a pinhole like an old Spitz, or tackle lithography with plates and lenses? Once I have my plates figured out, it should be a simple matter of scaling the hexagons and pentagons to suit a pinhole arrangement or make plates. BTW Old full frame Canon lenses for the EOS 35MM kits will project a 43mm diameter star plate. You can find them fir under $40. If you can make a PCB you can lithograph a plate with an ink jet transparency, Iron-on or other methods.
Posted by: Ron Walker May 15 2020, 10:58 AM
QUOTE(Philostopher1 @ May 14 2020, 11:39 PM) *
I am working on this with Paul Bourke now. Are you wanting to do a pinhole like an old Spitz, or tackle lithography with plates and lenses? Once I have my plates figured out, it should be a simple matter of scaling the hexagons and pentagons to suit a pinhole arrangement or make plates. BTW Old full frame Canon lenses for the EOS 35MM kits will project a 43mm diameter star plate. You can find them fir under $40. If you can make a PCB you can lithograph a plate with an ink jet transparency, Iron-on or other methods.
What focal length lenses are you using, or does that change depending on dome size?
Posted by: Philostopher1 May 16 2020, 03:45 AM
QUOTE(Ron Walker @ May 15 2020, 10:58 AM) *
What focal length lenses are you using, or does that change depending on dome size?
If I build a 32 plate system I am using Canon EF 35-80 1:4-5.6 III series. These will allow for different dome diameters. This allows between 64 degrees and 28 degrees projection\ FOV. I have 8 so far..
These accommodate a 43mm image circle, maybe a little more..
Posted by: Ron Walker May 16 2020, 10:33 AM
QUOTE(Philostopher1 @ May 16 2020, 03:45 AM) *
If I build a 32 plate system I am using Canon EF 35-80 1:4-5.6 III series. These will allow for different dome diameters. This allows between 64 degrees and 28 degrees projection\ FOV. I have 8 so far..
These accommodate a 43mm image circle, maybe a little more..
Do you have a way of calculating that or just do it by eye?
Does anyone have information on converting a planisphere projection to a dodecahedron?
Thanks
Chris
Posted by: Ron Walker Feb 9 2020, 09:05 AM
QUOTE(Chris4488 @ Feb 8 2020, 11:19 PM) *
Does anyone have information on converting a planisphere projection to a dodecahedron?
Thanks
Chris
Not at all sure how to do that as a planisphere tends to distort the positions of the stars as you look to the outside edge of the chart. Depending on the size, I would imagine a dodechedron could almost be plotted as a sphere. I'm thinking someone did the tipe of plotting you are requesting. I believe it is here someplace, I will look for it.
Welcome to OCP.
Posted by: Strgzr Feb 9 2020, 12:53 PM
QUOTE(Ron Walker @ Feb 9 2020, 09:05 AM) *
I believe it is here someplace, I will look for it.
Welcome to OCP.
To bad the search function is tits up!
And Welcome Chris!!
Posted by: Ken Miller Feb 9 2020, 02:48 PM
I did a dodecahedron map several years ago. It was based on some software that could plot stars on non-spherical surfaces. It was a close match for my actual Spitz A1. I have since sold the Spitz and gave the plot to the buyer. I even made a miniature Spitz dodecahedron with plots that I created with the software. The software is not readily available, and I would have to dredge through my archives to find a copy.
Ken
Posted by: Ken Miller Feb 9 2020, 03:23 PM
After doing more research, I found out that I got the software 9 years ago from someone named Charle Rupp. It looks like he had posted on this forum, but I don't know if he is still active. I found a copy of the software, and I suggest that you contact me to discuss it further. You can email me at "isotope115 at y . a . h . 0 . 0 . d0t . c. 0 . m"
Posted by: Ken Miller Feb 9 2020, 03:44 PM
Well, I researched some more and received a blow that is similar to too many others that have hit me recently. Charle passed away on January 3 of this year.
Posted by: Ron Walker Feb 9 2020, 04:40 PM
Have you reviewed this?
www.observatorycentral.com/index.php?showtopic=25472
Posted by: Ken Miller Feb 9 2020, 04:47 PM
QUOTE(Ron Walker @ Feb 9 2020, 03:40 PM) *
Have you reviewed this?
www.observatorycentral.com/index.php?showtopic=25472
Ron
That is really impressive!
Ken
Posted by: Strgzr Feb 9 2020, 04:53 PM
QUOTE(Ken Miller @ Feb 9 2020, 03:44 PM) *
Well, I researched some more and received a blow that is similar to too many others that have hit me recently. Charle passed away on January 3 of this year.
Very Sad! Rest In Peace Charle.
Posted by: Strgzr Feb 9 2020, 04:54 PM
QUOTE(Ron Walker @ Feb 9 2020, 04:40 PM) *
Have you reviewed this?
www.observatorycentral.com/index.php?showtopic=25472
Awesome!
Wish we could get an update from Philostopher! That's a Hellofa build he's got going on.
Posted by: Ron Walker Feb 10 2020, 09:57 AM
QUOTE(Strgzr @ Feb 9 2020, 04:54 PM) *
Awesome!
Wish we could get an update from Philostopher! That's a Hellofa build he's got going on.
I'm not at all sure if this idea ever panned out. Right now he is working on a single ball pinhole design which, as usual, is quite impressive.
Posted by: Ron Walker Feb 14 2020, 02:14 PM
QUOTE(Ron Walker @ Feb 10 2020, 09:57 AM) *
I'm not at all sure if this idea ever panned out. Right now he is working on a single ball pinhole design which, as usual, is quite impressive.
I talked with James and he did a lot of stuff for an optical projection but with the sky divided into 32 sections. This computer stuff is way above me so here is his email.
James Hicks
philostopher1@gmail.com
You can also reach him on his Facebook page "Planetarium Builders and Enthusiasts".
Posted by: Philostopher1 May 14 2020, 04:39 AM
QUOTE(Strgzr @ Feb 9 2020, 04:53 PM) *
Very Sad! Rest In Peace Charle.
Oh Man I am so sorry to hear this. I haven't been able to sign on for a long time. This really hurts and I have never met him.
Posted by: Philostopher1 May 14 2020, 04:49 AM
QUOTE(Chris4488 @ Feb 8 2020, 11:19 PM) *
Does anyone have information on converting a planisphere projection to a dodecahedron?
Thanks
Chris
Hey Chris,
I am going to talk to Paul Bourke and see if he can do a dodecahedron map. I think it's just a matter of plugging in the model. I am still vascillating on my optical plate projector. I was originally thinking of a Dodeca. Takayushi Ohira had a Megastar based on 12 plates.
At this point in the truncated icosahedron version, we have the 10,000=/- stars from Hipparcos mapped. If you have seen the JPGs I posted in my thread, the star magnitudes are represented as spheres. We need to figure out the scale for Sirius on a plate vs the smallest star that can be lithographed. I know Ohira was using laser lithography and getting down to 180 microns. I supect he is using step lithography. His first megastar were homemade plates using an argon laser direct write lithography I think.
Email me at Philostopher1@gmail.com
Are you in my FB group? Though this is a better forum to catalog a project and archive it.
Posted by: Ron Walker May 14 2020, 09:57 AM
QUOTE(Philostopher1 @ May 14 2020, 04:49 AM) *
Hey Chris,
I am going to talk to Paul Bourke and see if he can do a dodecahedron map. I think it's just a matter of plugging in the model. I am still vascillating on my optical plate projector. I was originally thinking of a Dodeca. Takayushi Ohira had a Megastar based on 12 plates.
At this point in the truncated icosahedron version, we have the 10,000=/- stars from Hipparcos mapped. If you have seen the JPGs I posted in my thread, the star magnitudes are represented as spheres. We need to figure out the scale for Sirius on a plate vs the smallest star that can be lithographed. I know Ohira was using laser lithography and getting down to 180 microns. I supect he is using step lithography. His first megastar were homemade plates using an argon laser direct write lithography I think.
Email me at Philostopher1@gmail.com
Are you in my FB group? Though this is a better forum to catalog a project and archive it.
I would suggest that 1st magnitude and brighter stars be projected by separate projectors. They will project as big moons if placed on a single star plate and really destroy the illusion.
Posted by: Philostopher1 May 14 2020, 11:31 PM
QUOTE(Ron Walker @ May 14 2020, 09:57 AM) *
I would suggest that 1st magnitude and brighter stars be projected by separate projectors. They will project as big moons if placed on a single star plate and really destroy the illusion.
Good point! That is how Minolta and Zeiss are doing it in the Infinium and Universarium.
Posted by: Philostopher1 May 14 2020, 11:39 PM
QUOTE(Chris4488 @ Feb 8 2020, 11:19 PM) *
Does anyone have information on converting a planisphere projection to a dodecahedron?
Thanks
Chris
I am working on this with Paul Bourke now. Are you wanting to do a pinhole like an old Spitz, or tackle lithography with plates and lenses? Once I have my plates figured out, it should be a simple matter of scaling the hexagons and pentagons to suit a pinhole arrangement or make plates. BTW Old full frame Canon lenses for the EOS 35MM kits will project a 43mm diameter star plate. You can find them fir under $40. If you can make a PCB you can lithograph a plate with an ink jet transparency, Iron-on or other methods.
Posted by: Ron Walker May 15 2020, 10:58 AM
QUOTE(Philostopher1 @ May 14 2020, 11:39 PM) *
I am working on this with Paul Bourke now. Are you wanting to do a pinhole like an old Spitz, or tackle lithography with plates and lenses? Once I have my plates figured out, it should be a simple matter of scaling the hexagons and pentagons to suit a pinhole arrangement or make plates. BTW Old full frame Canon lenses for the EOS 35MM kits will project a 43mm diameter star plate. You can find them fir under $40. If you can make a PCB you can lithograph a plate with an ink jet transparency, Iron-on or other methods.
What focal length lenses are you using, or does that change depending on dome size?
Posted by: Philostopher1 May 16 2020, 03:45 AM
QUOTE(Ron Walker @ May 15 2020, 10:58 AM) *
What focal length lenses are you using, or does that change depending on dome size?
If I build a 32 plate system I am using Canon EF 35-80 1:4-5.6 III series. These will allow for different dome diameters. This allows between 64 degrees and 28 degrees projection\ FOV. I have 8 so far..
These accommodate a 43mm image circle, maybe a little more..
Posted by: Ron Walker May 16 2020, 10:33 AM
QUOTE(Philostopher1 @ May 16 2020, 03:45 AM) *
If I build a 32 plate system I am using Canon EF 35-80 1:4-5.6 III series. These will allow for different dome diameters. This allows between 64 degrees and 28 degrees projection\ FOV. I have 8 so far..
These accommodate a 43mm image circle, maybe a little more..
Do you have a way of calculating that or just do it by eye?