Hi Barry,

Welcome to the group! I think you joined about 10 minutes after I
started the group.

Have you started construction of a planetarium yet? I have really
enjoyed looking at your website. You did such a nice job with the
observatory that I know your planetarium will be something special.

I too have thought about using Stellarium as my planetarium software.
One of the developers has written a projector into the latest CVS
version that all ows one to use a mirror instead of a fisheye lens. As
soon as I get Linux loaded I'm going to try it. He said he would keep
tweaking it till it works for us. At last digital planetariums can be
within the reach of just ordinary folks.

Hi all,

Greg here. It's such a small group so far I thought we should have some
introductions. I'll start. See the next post.

Greg here. I run the astronomy program at a resort hotel in
California. I've been interested in astronomy since I was a boy
growing up near the NASA facility in Huntsville Alabama. If my
parents did not take me there at least once, or twice a year I would
hold my breath till they gave in.

I really became obsessed when I started working at the resort. We
have such a beautiful sky here. The resort had an old Celestron scope
sitting unused in a closet. I convinced them to let me start a
program a few summers ago.

Astronomy is a very popular program with our guests especially in the
summer. Now we have a 16" Newt on a sphere mount, a 10" Meade LX200,
the 8" Celestron, and a Coronado PST solar scope. The next progect is
an observatory dome so we can observe in the winter.

I found that I really enjoy showing our guests the sky. I'm addicted
to the sound of folks saying "wow!" just under their breath. It's
very rewarding.

Lately I have been thinking of staring a program of taking astronomy
and science education to local schools. That is how I became
interested in building a planetarium.

Well, that's about it for now. I'll post pictures and progress
reports on my planetarium as it happens.

Hi Greg

It will be some time before I am able to start my small planetarium. I
just paid out $A11000 to send my partner to Wimbledon to see the tennis
this year so all my surplus for the next 12 months has been used up.

I should be able to get a good projector in about 7 months. This will
allow me to do some experimenting. As for a dome I will need to
construct something like my observatory dome. Probably with
sectionalised pieces like someone described on the sourceforge forum.

As you can see from my web site I have my finger in a lot of pies and
my time is limited even though I am retired. These days I spend a lot
of time in front of the computer answering technical problems on many
forums and sending emails to friends and relations.

I have been playing with the Stellarium program for about 2 months now
making and positioning pictures of deep sky objects for the display,
Making a horizon panorama, scripts of eclipses and assisting Matthew
with a manual. Most of the results of this I have put on another web
site www.geocities.com\wendygblyde

My next immediate problem is to become proficient in the Linux
operation system about which I know very little but which I have
decided is the way to go. I have ordered a set of discs and when they
arrive I will get into it.

Keep up the good work.

Barry Gerdes

Beaumont Hills Observatory
Sirius 2.3 metre fibre glass Dome
S 33' 41' 43.69"    E 150' 56' 32.56"
LX200GPS 12" F10 Permanent Polar mounted
Home page http://www.geocities.com/barrykgerdes


--- In small_planetarium@yahoogroups.com, "Greg" <greggyvt1@...> wrote:
>
> Hi Barry,
>
> Welcome to the group! I think you joined about 10 minutes after I
> started the group.
>
> Have you started construction of a planetarium yet? I have really
> enjoyed looking at your website. You did such a nice job with the
> observatory that I know your planetarium will be something special.
>
> I too have thought about using Stellarium as my planetarium software.
> One of the developers has written a projector into the latest CVS
> version that all ows one to use a mirror instead of a fisheye lens.
As
> soon as I get Linux loaded I'm going to try it. He said he would keep
> tweaking it till it works for us. At last digital planetariums can be
> within the reach of just ordinary folks.
>

Hi Barry,

It will be fun exchanging ideas for our planetariums. Sounds like we
have very simular plans.

I am also at the very same stage in my Linux education. I wanted to
try it because of the CVS versions of Stellarium... and everyone else
is doing it!

Greg

--- In small_planetarium@yahoogroups.com, "Barry Gerdes"
<barrygastro@...> wrote:
>
> Hi Greg
>
> It will be some time before I am able to start my small
planetarium. I
> just paid out $A11000 to send my partner to Wimbledon to see the
tennis
> this year so all my surplus for the next 12 months has been used
up.
>
> I should be able to get a good projector in about 7 months. This
will
> allow me to do some experimenting. As for a dome I will need to
> construct something like my observatory dome. Probably with
> sectionalised pieces like someone described on the sourceforge
forum.
>
> As you can see from my web site I have my finger in a lot of pies
and
> my time is limited even though I am retired. These days I spend a
lot
> of time in front of the computer answering technical problems on
many
> forums and sending emails to friends and relations.
>
> I have been playing with the Stellarium program for about 2 months
now
> making and positioning pictures of deep sky objects for the
display,
> Making a horizon panorama, scripts of eclipses and assisting
Matthew
> with a manual. Most of the results of this I have put on another
web
> site www.geocities.com\wendygblyde
>
> My next immediate problem is to become proficient in the Linux
> operation system about which I know very little but which I have
> decided is the way to go. I have ordered a set of discs and when
they
> arrive I will get into it.
>
> Keep up the good work.
>
> Barry Gerdes
>
> Beaumont Hills Observatory
> Sirius 2.3 metre fibre glass Dome
> S 33' 41' 43.69"    E 150' 56' 32.56"
> LX200GPS 12" F10 Permanent Polar mounted
> Home page http://www.geocities.com/barrykgerdes
>
>

Hi everyone,

I just wanted to ask the group members to describe the plans for your
planetariums. How do you intend to use your project? Have you started
construction? Do you have a planetarium up and running? Portable, or
fixed location? Digital, or other type of projector? Any advice for
the rest of us? Etc, etc.

I'll start:

I'm planning on a 16' diameter 3v geodesic dome. The dome will be
portable and will be assembled by the students at each location. The
dome geodesic triangles are 1/8" plywood held together by industrial
strength Velcro. I have started cutting the pentagon triangles and
it's going well. The next step will be to paint the panels, and apply
the Velcro hook tape to the sides.

I'm going to use a homemade version of the MirrorDome system for my
projection. I ordered my spherical mirror. I'll borrow a projector
till I get the distortion issues worked out. One of the Stellarium
developers has agreed to help write the "warping" in real time using
the software. I think it's the best solution on a budget. I'll
project a combination of Stellarium, Celestia, and home-rendered
content.

My plan is to use the planetarium with the guests at the resort where
I work, and to take it to the local schools if invited. No plans yet
for a full planetarium business... but who knows.

I look forward to hearing about all of your projects!

Greg

I'm afraid l've slid into this interest in small planetariums by teaching at
junior high and
high schools.   They have not always been successful, but I've come to recognize
a the
value in a small planetarium.  (Mark Twain is supposed to have said something
along the
lines of no man is a failure he can always serve as a bad example.) At my first
teaching
position I and another teacher hauled a donated telescope and some celestrons
out to
show students during a unit on space.  We always lucked out and had good
weather, but
we didn't know where we were looking at.  (I've improved a bit since then taking
courses
and joining an amateur group in the area).

   I discovered a portable planetarium plan in "Earth at Hand" from NSTA
(Washington, D.C.:
National Science Teachers Association, 1993.) which was basically a 5 m by 5
meter pillow
of black garden plastic with holes cut into the top to represent the stars.  It
is blown up
with a fan through a tube on one side.  A flap covers a door on the other.  Only
one
season's stars could be displayed at a time and it didn't move, of course.   The
great part
was in the making.  Students projected the constellation from an overhead
projector on to
the plastic and made marks with tape.  They learned the relative position
quickly and were
proud to demonstrate this to younger classes.   (I noticed that a recent
National Science
Teacher Association Science Teacher had an article on making a similar, round
planetarium with no floor (similar to the star lab dome)  it is Stockdale,
Dennis, Oct. 1997,
Science Teacher.  Depending on the group there was great variation in quality (I
had made
4 or 5 of these).  All kids liked going into the inflated dome and "chillin'"
under the "stars"
but they were not the best for doing any actual teaching about what is up in the
sky and
how it changes through the night.

Next, I've made the planetarium (basically a pin hole type projection from a
globe) from
Lawrence Hall of science (http://store.yahoo.com/lawrencehallofscience/
starmakplank.html) it projects on a plastic umbrella that was awkward to hang
and was
not terribly sturdy (plenty of rips after only 2 uses)  It doesn't make for a
practical way of
getting a classroom of teenaged students to look together.  I plan to use this
with my
daughter's preschool class (the darker bag or starlab is too much for them).

After volunteering to set up some night viewing times for a local small natural
history
museum (every first thursday) and being clouded out EVERY time I began looking
more
seriously for a realistic small planetarium.  The magazine SKy and Telescope
reviewed new
digital projectors for planetariums (not the magazine's typical fare).  However
the more I
looked the more shocked I was in the price.  My district was unlikely to afford
one for the
use of a small elective.  I decided to approach local businesses to support a
lower tech
(presumably easier to maintain and trouble shoot) Starlab  (www.starlab.com). 
The local
museum would be the managers.  They have since succeeded (with fundraising from
me
and others) and now would like to have a coordinator present the programs (most
teachers
we asked want this).  It means that the darn thing is not accessible or
affordable for my
district for one class at the high school level.  (At least not for on-going use
- no parent
teacher association money).  I also had a hard time arranging space for it for
my class (I
wound up swapping with the theatre teacher for space).  The stellerium software
and the
comments about making geodesic domes are very exciiting and I've only begun to
look for
how to get a fish eye lens.

Has anyone found an inexpensive (relatively) fish eye lens/projector option? 
The
commercial programs and projectors are out of site.   Is the mirror system
possible with
the current soft ware?

Alan

Hi all,

You've all beaten me to the punch for introductions, but here goes
nothing...

I currently work for Digitalis Education Solutions, Inc. Since you all
know Stellarium, you know that the president of Digitalis is one of
the developers (Rob Spearman) and that we use Stellarium in our
portable projector, the Digitarium Alpha.

However, I'm not here to do sales pushes. I'm certainly happy to
answer any questions you have about our projector, though. : )

My main interest is in helping people teach with small planetariums. I
see a trend with digital projectors to just play prerecorded shows,
which I think are fine once in a while and are (for the most part)
enjoyable. However, I think that people miss out on the enormous
educational capabilities of a digital projector by just pushing the
play button. I really enjoy letting people ask questions and then
figuring out a way to show them the answers on the dome.

My background: I was a member of Pacific Science Center's Science On
Wheels outreach program for eight years. PSC is based in Seattle, and
the Science On Wheels program visits K-8 schools in all 39 counties.
Science On Wheels includes two Starlab planetariums with their
astronomy program, and that is how I first became interested in
portable planetariums.

I also supervised PSC's fixed Smith planetarium for about a year,
which is a 26 ft/8m dome with a Spitz 512 projector. All shows in the
Smith are live and interactive. If you're ever in Seattle, check it
out; it's a great space with a fantastic staff.

Any questions, feel free to ask. I look forward to reading discussions
on this list.

Greg, you might want to post a message about this group on Dome-L, the
planetarium listserv. I think that would help spread the word.

Cheers,
Karrie
--
Karrie Berglund
Director of Education
Digitalis Education Solutions, Inc.
PO Box 2976
Bremerton, WA 98310

360.616.8915

http://DigitalisEducation.com

Hi Greg et Al

I would love to have a big specially designed planetarium but that
would be a mammoth and expensive project. The way I see it is to have
a small portable suedo planetarium dome that can be quickly set up in
a large room (class room) and be used to display the night sky to a
small group of people.

I have made a couple of scale drawings in AutoCad to get some idea of
the minimum requirements to display an acceptable replica of the sky
as seen from someone prone on the ground looking up at the sky.  The
need to have a hemispherical dome is not as necessary as everyone
thinks as the view one sees from this position is basically 2D and
the horizon is only in the periferal vision.

The simple projectors can have a display field of around 60 degrees
and in a darkened room can throw a suitable picture about 8 ft in
diameter. I think that with a suitable lens modification I could get
the display field up to 70 degrees. (This idea was checked using the
field of view from a wide angle lens on a SLR camera)

Now using this idea I could make a spherical curved screen around 8'
in diameter with radius if curvature 6.5. It would look like an
inverted dish. That could be illuminated by a projector pointing up
from the focal point. The screen would be prefabricated in sections
(for portability) and supported by a simple framework and the area
enclosed by a heavy opaque curtain. This arrangement could
accommodate up to 8 or 9 children laying on padded mats.

Using this idea with a high resolution projector would reduce the
need for warping and be capable of producing a fantastic view of the
night sky along with any other dialogue necessary for a presentation.

Think about it!

Barry Gerdes

Beaumont Hills Observatory
Sirius 2.3 metre fibre glass Dome
S 33' 41' 43.69"    E 150' 56' 32.56"
LX200GPS 12" F10 Permanent Polar mounted
Home page http://www.geocities.com/barrykgerdes



--- In small_planetarium@yahoogroups.com, "Greg" <greggyvt1@...>
wrote:
>
> Hi everyone,
>
> I just wanted to ask the group members to describe the plans for
your
> planetariums. How do you intend to use your project? Have you
started
> construction? Do you have a planetarium up and running? Portable,
or
> fixed location? Digital, or other type of projector? Any advice for
> the rest of us? Etc, etc.
>
> I'll start:
>
> I'm planning on a 16' diameter 3v geodesic dome. The dome will be
> portable and will be assembled by the students at each location.
The
> dome geodesic triangles are 1/8" plywood held together by
industrial
> strength Velcro. I have started cutting the pentagon triangles and
> it's going well. The next step will be to paint the panels, and
apply
> the Velcro hook tape to the sides.
>
> I'm going to use a homemade version of the MirrorDome system for my
> projection. I ordered my spherical mirror. I'll borrow a projector
> till I get the distortion issues worked out. One of the Stellarium
> developers has agreed to help write the "warping" in real time
using
> the software. I think it's the best solution on a budget. I'll
> project a combination of Stellarium, Celestia, and home-rendered
> content.
>
> My plan is to use the planetarium with the guests at the resort
where
> I work, and to take it to the local schools if invited. No plans
yet
> for a full planetarium business... but who knows.
>
> I look forward to hearing about all of your projects!
>
> Greg
>

Hi Karrie,

A huge welcome to our small group! I really wish I could afford one
of your projectors. I first found out about Stellarium from a link on
your company's website. I think you guys have a fantastic product.
Thanks also for the astronomy lesson plans on your website.

I could not agree more about relying too much on pre-recorded shows.
I plan to have only about 1/4 of the time in the dome used by pre-
recorded content. I love the questions I hear doing astronomy viewing
session at night. I think it would be fun to try to answer questions
using the various software and scripts in a dome. Were you a science
teacher before your work at the Science Center?

Interesting work at the Pacific Science Center! I would love to come
up there for a visit sometime. Would it be possible to kind-of tag
along with one of the shows, and one of the traveling shows as well?
Do you know of anyone using your projector, and lesson plans here in
California? I would love to see it in action.

Let me know if Rob needs a California sales rep! I'm sort of
serious... we run a family camp here in the summer ( www.mslodge.com )
and we have about 200 guests each week. Many of them are teachers,
and the rest know plenty of teachers because they all have school age
children. I'm planning on showing my planetarium off to hundreds of
people each week during the summer. Prospective buyers could come to
our resort to view a Digitarium Projector, or I could demonstrate one
at their location at no expense to you.

Sorry for that last little rant... but I'm obsessed!

Thanks again for joining. I look forward to hearing more about all
the things you are involved with. With your experience level we are
bound to learn a great deal.

Greg



--- In small_planetarium@yahoogroups.com, "bergieberglund"
<bergieberglund@...> wrote:
>
> Hi all,
>
> You've all beaten me to the punch for introductions, but here goes
> nothing...
>
> I currently work for Digitalis Education Solutions, Inc. Since you
all
> know Stellarium, you know that the president of Digitalis is one of
> the developers (Rob Spearman) and that we use Stellarium in our
> portable projector, the Digitarium Alpha.
>
> However, I'm not here to do sales pushes. I'm certainly happy to
> answer any questions you have about our projector, though. : )
>
> My main interest is in helping people teach with small
planetariums. I
> see a trend with digital projectors to just play prerecorded shows,
> which I think are fine once in a while and are (for the most part)
> enjoyable. However, I think that people miss out on the enormous
> educational capabilities of a digital projector by just pushing the
> play button. I really enjoy letting people ask questions and then
> figuring out a way to show them the answers on the dome.
>
> My background: I was a member of Pacific Science Center's Science On
> Wheels outreach program for eight years. PSC is based in Seattle,
and
> the Science On Wheels program visits K-8 schools in all 39 counties.
> Science On Wheels includes two Starlab planetariums with their
> astronomy program, and that is how I first became interested in
> portable planetariums.
>
> I also supervised PSC's fixed Smith planetarium for about a year,
> which is a 26 ft/8m dome with a Spitz 512 projector. All shows in
the
> Smith are live and interactive. If you're ever in Seattle, check it
> out; it's a great space with a fantastic staff.
>
> Any questions, feel free to ask. I look forward to reading
discussions
> on this list.
>
> Greg, you might want to post a message about this group on Dome-L,
the
> planetarium listserv. I think that would help spread the word.
>
> Cheers,
> Karrie
> --
> Karrie Berglund
> Director of Education
> Digitalis Education Solutions, Inc.
> PO Box 2976
> Bremerton, WA 98310
>
> 360.616.8915
>
> http://DigitalisEducation.com
>

Karrie,

I forgot to ask how to access that Dome-L group. Could you point me
toward a link for the list?

Hey Greg,

Here's a link to the sign up page:
http://planetarium.net/dome-l/

Cheers,
Karrie

--- In small_planetarium@yahoogroups.com, "Greg" <greggyvt1@...> wrote:
>
> Karrie,
>
> I forgot to ask how to access that Dome-L group. Could you point me
> toward a link for the list?
>

Hi Alan,

Sounds like you are the kind of teacher who would do just about
anything to help his students learn. You are exactly the kind of
group member we can all learn from as well.

The first couple of planetariums you mentioned sound like great
projects. Could you post a link to the articles if they are online? I
could not find pictures of that Star Maker Planetarium on the
Lawrence website. If you have pictures of any of the projects you
have done please upload them to the Photos area of the group page.

Did you read the introduction for Karrie? She works for Digitalis
Education. They make the Digitarium Projector, which I believe is the
least expensive fisheye/digital projector. I have given up on trying
to place a fisheye lens on a digital projector. Seems like that is
something that has to be engineered very well.

The mirror projection system seems very good for folks like me (and
you)on a very tight budget. It is possible with Stellarium as one of
the developers named Johannes has written a very beta "warping"
projector into the latest CVS version. I'm loading Linux on one of my
computers so I can try it out. I'll let you know how it goes. There
is one company doing mirror projection. It's the MirrorDome System.
Everyone on the Stellarium forums is hoping that will make their
modified source code avaliable.

I bet your students would have a great time building a geodesic dome.
I'll post all the links I have to the Links section of the group.

It's great to have a teacher in the group! I look forward to hearing
all your adventures in the classroom.

Greg


--- In small_planetarium@yahoogroups.com, "middleboroscienceteacher"
<middleboroscienceteacher@...> wrote:
>
> I'm afraid l've slid into this interest in small planetariums by
teaching at junior high and
> high schools.   They have not always been successful, but I've come
to recognize a the
> value in a small planetarium.  (Mark Twain is supposed to have said
something along the
> lines of no man is a failure he can always serve as a bad example.)
At my first teaching
> position I and another teacher hauled a donated telescope and some
celestrons out to
> show students during a unit on space.  We always lucked out and had
good weather, but
> we didn't know where we were looking at.  (I've improved a bit
since then taking courses
> and joining an amateur group in the area).
>
>   I discovered a portable planetarium plan in "Earth at Hand" from
NSTA (Washington, D.C.:
> National Science Teachers Association, 1993.) which was basically a
5 m by 5 meter pillow
> of black garden plastic with holes cut into the top to represent
the stars.  It is blown up
> with a fan through a tube on one side.  A flap covers a door on the
other.  Only one
> season's stars could be displayed at a time and it didn't move, of
course.   The great part
> was in the making.  Students projected the constellation from an
overhead projector on to
> the plastic and made marks with tape.  They learned the relative
position quickly and were
> proud to demonstrate this to younger classes.   (I noticed that a
recent National Science
> Teacher Association Science Teacher had an article on making a
similar, round
> planetarium with no floor (similar to the star lab dome)  it is
Stockdale, Dennis, Oct. 1997,
> Science Teacher.  Depending on the group there was great variation
in quality (I had made
> 4 or 5 of these).  All kids liked going into the inflated dome
and "chillin'" under the "stars"
> but they were not the best for doing any actual teaching about what
is up in the sky and
> how it changes through the night.
>
> Next, I've made the planetarium (basically a pin hole type
projection from a globe) from
> Lawrence Hall of science
(http://store.yahoo.com/lawrencehallofscience/
> starmakplank.html) it projects on a plastic umbrella that was
awkward to hang and was
> not terribly sturdy (plenty of rips after only 2 uses)  It doesn't
make for a practical way of
> getting a classroom of teenaged students to look together.  I plan
to use this with my
> daughter's preschool class (the darker bag or starlab is too much
for them).
>
> After volunteering to set up some night viewing times for a local
small natural history
> museum (every first thursday) and being clouded out EVERY time I
began looking more
> seriously for a realistic small planetarium.  The magazine SKy and
Telescope reviewed new
> digital projectors for planetariums (not the magazine's typical
fare).  However the more I
> looked the more shocked I was in the price.  My district was
unlikely to afford one for the
> use of a small elective.  I decided to approach local businesses to
support a lower tech
> (presumably easier to maintain and trouble shoot) Starlab
(www.starlab.com).  The local
> museum would be the managers.  They have since succeeded (with
fundraising from me
> and others) and now would like to have a coordinator present the
programs (most teachers
> we asked want this).  It means that the darn thing is not
accessible or affordable for my
> district for one class at the high school level.  (At least not for
on-going use - no parent
> teacher association money).  I also had a hard time arranging space
for it for my class (I
> wound up swapping with the theatre teacher for space).  The
stellerium software and the
> comments about making geodesic domes are very exciiting and I've
only begun to look for
> how to get a fish eye lens.
>
> Has anyone found an inexpensive (relatively) fish eye
lens/projector option?  The
> commercial programs and projectors are out of site.   Is the mirror
system possible with
> the current soft ware?
>
> Alan
>

Thanks Karrie!

I signed up for the list. I'll ask the moderator if it's ok to post a
link to this group.

Greg

--- In small_planetarium@yahoogroups.com, "Greg" <greggyvt1@...> wrote:
>
> The first couple of planetariums you mentioned sound like great
> projects. Could you post a link to the articles if they are online? I
> could not find pictures of that Star Maker Planetarium on the
> Lawrence website. If you have pictures of any of the projects you
> have done please upload them to the Photos area of the group page.

The articles are on the NSTA.org web site (under journals) but require
membership.  The
author's contact information is at the end of the article.  I've sent him a note
asking if he
would wish to share here.
Dennis L. Stockdal. Asheville High School, 419 McDowell Street, Asheville,
NC 28803; e-mail: dstockdale@....  I believe he had the student draw in the
stars on
clear plastic material.   The other is a book (EARTH AT HAND) that might be
found in a
library - I'm not sure where my copy has gone.

I will take a picture of the star maker planetarium (I hesitated for a long time
since there
was no picture)  I have some other photos at school of the last plastic bag
planetarium
made.


>
> Did you read the introduction for Karrie? She works for Digitalis
> Education. They make the Digitarium Projector, which I believe is the
> least expensive fisheye/digital projector. I have given up on trying
> to place a fisheye lens on a digital projector. Seems like that is
> something that has to be engineered very well.
>
> The mirror projection system seems very good for folks like me (and
> you)on a very tight budget. It is possible with Stellarium as one of
> the developers named Johannes has written a very beta "warping"
> projector into the latest CVS version. I'm loading Linux on one of my
> computers so I can try it out. I'll let you know how it goes. There
> is one company doing mirror projection. It's the MirrorDome System.
> Everyone on the Stellarium forums is hoping that will make their
> modified source code avaliable.

I did see the digitalis information while fundraising for our starlab.  It
looked great, but I
thought there would be less technical experience needed to run the starlab, and
we might
be able to service it for a longer time period.   It was also not guarenteed
that we would
raise the money for starlab projector, the relatively inexpensive one they
offered was
nearly twice that price.  I'm beginning to think many would have appreciated the
ability to
play a pre-recorded DVD.  THe museum has hired a part time coordinator, but I'm
not sure
they are making enough to make the position sustainable.

I have no projector to play with, but I recall a fish eye that attached like a
filter to a camera
lens.  I was hopeful that I could find one that could fit or be jury-rigged to
fit the schools
projectors.  What happens to the image when you've experimented with fish eyes?
Even if
I just get to project to a large flat screen I think stellarium will add plenty.

>
> I bet your students would have a great time building a geodesic dome.
> I'll post all the links I have to the Links section of the group.
>
> It's great to have a teacher in the group! I look forward to hearing
> all your adventures in the classroom.
>
> Greg
>
Thank you for arranging this group.
Alan

Hi Barry,

I posted a link (in the Links section)to a guy named Yves who has
constructed something like you described.

Looks good... especially for a small group.

BTW: planetariums are WAY more important than golf. Get your priorities
straight! just kidding

Greg

hi greg, and all
I have just added this group.

i'm Yves Lhoumeau, a "small planetarium" maker.see at
http://perso.wanadoo.fr/yves.lhoumeau/astronomie/diffusion/animation/pl
anetarium/planetarium2.htm

it's note a truly immersive dome, but it works very well, for 6
persons, in my living room.
a cardboard dome is easy to build, and cheap. Try it !

my wife don't like this dome in our living, so for each time, i must
build it.
if any have a idee for build a cardboard dome fastest...

Yves

Hi Yves,

Welcome! I was hoping you would join after I saw your post on the
Stellarium group. Did you notice that I already had a link to your
website on the Links Page? Barry, one of the other memebers, mentioned
something about building a dome like yours a few days ago, so I added
the link.

Keep up the good work and send lots of pictures!

Greg

Ok. I've finally found my way here
    I have a couple of domes. One 12' in the basement, and a 16' dia
dome in the back yard, that I built out of styrofoam.
     I'm basicly set up using a hemispherical mirror, but I also have an
attachment on my Kodak Digital projector to which I can attach a 10mm
Kenko fisheye lens. The fisheye lens steals a lot of the light passing
through. And you still have to project on a curved surface for minimum
distortion
   Hopefully a few pictures I have sent by email can be posted here.
Regards
Terry Renner

Hi Yves,

Thanks so much for updating your website (see the Links Page)with the
new drawings. They really help explain the layout of the planetarium. I
think many of the new members for this Group will be interested in
building their own projects. All the photos and drawings will be a big
help to everyone.

I'm always curiuos how folks plan to use their panetarium. Will it be
for you and your family? Will you invite the neighbors? Take it to
public places like a school? How often will you set up your
planetarium? Yves, if it's not too much trouble, please open up a new
thread on how you plan to use your project. It's no good to see really
valuable information buried in a long thread.

Thanks again,
Greg

I thought I would mention. In experimenting with different dome
construction ( Geodesic, Soccor ball, etc )I found I ended up with a
lot of waste material. Being terminally broke, Left over material gives
me bad dreams at night.
   My "foam dome" is designed after the good old Canadian igloo. If you
have a 4' by 8' sheet of something, and cut it into squares about 22
1/2" by 22 1/2", you end up with a dome right on 16' in diameter. That
would be the inside measurment. Since the foam I used was 2" thick, you
have to be consistant where you measure to.
   All you math wizzes. Get your calculator out and check this out
   Sidenote. Styrofoam doesn't stop ANY light! OR sound! I found a
material to cover lumber stored outside, that is really good at cutting
down light.
   Cutting foam. I screwed a large box cutter blade to a 16" long stick.
I put mineral oil on it every second cut, and this worked very smoothly.
   I experimented with a piece of wire out of an old toaster, and a
battery charger, and that worked fine. Be aware that the smoke is
formaldyhide, and very poisonous.
   Happy building !

Regards
Terry Renner

Yves Lhoumeau,

Thank you for your web page, your screen would work well in a classroom.  Do you
use a
wide angle or a fish eye lens on the projector?

  Thanks
Alan
--- In small_planetarium@yahoogroups.com, "yves lhoumeau" <yves.lhoumeau@...>
wrote:
>
> ok, i've seen the link. thank's greg.
> i've been a update on my web page.
> you can now see 2 pictures, how to place the projector and the dome.
> Yves
>

This is a question I have.
   Does anyone have any knowledge of how to warp the Stellarium
software?
   When reflecting off the hemispherical mirror, there is distortion,
even though most of the image in focus i.e. The text is readable. But
the pixals are really squished at the top.
   Another note. I am using a 800 by 600 resolution projector, and it's
like looking through a screen door.
   Another note. I have tried a Kenko 10mm fisheye lens on the
projector, and I'm able to get reasonable rsolution, But you sure get a
lot more light reflecting off the mirror
Regards
Terry Renner

Hi Barry,

Thanks for the new link and the work you are doing on the Stellarium
landscapes and scripts.

Greg

Hi Terry,

Now we're talking! This is something that has been driving me crazy
for about two months now.

As you have noticed, Stellarium must be "warped" to display correctly
when projected off a spherical mirror that is not placed at the
center of the dome (see Paul Bourke's pages). There are a couple of
ways to do this.

If you do not care about using Stellarium interactively, you could
take Stellarium images in a 3D program, model the environment (dome
size, mirror size, projector parameters, etc) and raytrace the scene
using a camera in place of the projector. The refleced image off the
virtual mirror will be warped correctly. Paul Bourke does a great job
of explaning that in one of his pages (see the Lnks Page). You could
also use this method to make your own media that could be displayed
on the dome using other photos, and video.

The other method is to actually change the software to project a pre-
distorted image. The folks down at Swinburne University have done
this, however they sell a package called MirrorDome, and they do not
release their modified Stellarium. There is some discussion about
that and the open source license, but that is another issue.

On a very bright note... one of the Stellarium developers (Johannes)
has written a spherical mirror projector into the source code. If you
have Linux (I'm installing and learning Linux just for this purpose)
you can download the latest CVS version of the software and try it
out. The feature might not ever make it into official releases of
Stellarium, but at least we have a developer who is willing to make
it work for a few of us. Read the forum posts and threads on the
Stellarium Source Forge website to find out more.

Seems like we are faced with hoping that MirrorDome releases their
modified source code, or being very patient and working with
Johannnes for the feature. Johnnes has been wonderful on the the
forum and in personal emails. If you have Linux, you can give it a
try right now.

Greg

Hi all,

Hopefully you have noticed that some really good info has already
passed though this group. We are not the only folks out there
interested in this subject. Please, if you are a member of any other
groups that might have an interest in this, post a quick message in
those forums. Let's form a big happy family.

Greg

Hi Terry,

I'm curiuos about your fisheye lens configuration. The conventional
wisdom is that it is just not possible. How do you attach the lens to
the projector? Is the fisheye lens you use made for projectors? If so,
where did you get it?. Is it worth doing because of the optics? Ok for
home use, but not for professional use?

If you could, please send us some photos, or drawings of your lens
configuration.

Thanks,
Greg