PDA

View Full Version : Home planetariums



eugenek
2007-Nov-09, 10:13 PM
Does anyone have any experience with these that they could share?

I'm thinking about two varieties here. The first is a toy which usually comes in under 100 USD and displays stars and usually constellations on the ceiling or walls. Usually the display has the stars dark and space is lite. I'm wondering if it covers the entire room, fake horizon to fake horizon or just where the light is directly pointing? Are they accurate? My goal, if I should get one, is to use it as an aid to paint glow in the dark stars on my ceiling.

The second is something which comes in around 100 - 400 USD and uses LEDs to put stars on the ceiling/walls. The pictures make it look similar to what might be seen in the real nightsky. Same questions as the toy but also are the stars pinpoints or do they become noticeably blurry? With this one, I wouldn't even need to paint the stars on my ceiling if the display is nice and accurate.

Hopefully, below are a couple pictures of what I'm talking about.

Thanks.

Neverfly
2007-Nov-09, 10:26 PM
You will make me drool...

There are a few home planetariums on the market that are quite expensive, but worth the cost (If affordable). They have lenses, not a flashlight, so you can adjust without worry of it being blurry or smeary.

This is one of those cases where you get what you pay for. Take such an expenditure seriously if you are looking for quality.
Take notes and compare them. But don't worry about the expensive models misleading you to make the sale. If they claim to not be blurry- They won't be blurry;)

The $20 to $100 (USD) toy styles are mostly intended for young ones and children, and tend to exxagerate the capabilities of the product.

KaiYeves
2007-Nov-09, 10:57 PM
Responding to title:
Oh, gosh, that would be so awesome!
Right up there with the personal IMAX theater.

aurora
2007-Nov-12, 05:01 AM
This one is great, but more expensive than you have in mind.

http://digitaliseducation.com/astronomy_education.html

Yet, it is a lot cheaper than the mechanical ones.

Starlab now has a knock-off of it, a digital planetarium:
http://www.starlab.com/slds.html

eugenek
2007-Nov-12, 02:51 PM
This one is great, but more expensive than you have in mind.

http://digitaliseducation.com/astronomy_education.html

Yet, it is a lot cheaper than the mechanical ones.

Starlab now has a knock-off of it, a digital planetarium:
http://www.starlab.com/slds.html


Heh. I've seen the starlab one and sent a link to my wife some months back. Her only response was "no." I guess the $48,000 price tag is just a bit over our budget. I shouldn't have been surprised. For years now I've asked her for a starship for Christmas and have yet to receive it. I don't need anything top of the line, just something that can sustain warp 4. I keep telling her that if she gets me one I'll stop complaining about our lack of dark skies.

Maybe I'll have better luck with the Digitalis planetarium. It's cheaper. However, I do suspect we'll have difficulty fitting it in the bonus room though.

My other option is to map out the section of sky I want on graph paper. Punch holes through the graph paper where the stars are then tack it to the ceiling and paint where the stars are.

Neverfly
2007-Nov-12, 04:54 PM
Heh. I've seen the starlab one and sent a link to my wife some months back. Her only response was "no." I guess the $48,000 price tag is just a bit over our budget. I shouldn't have been surprised. For years now I've asked her for a starship for Christmas and have yet to receive it. I don't need anything top of the line, just something that can sustain warp 4. I keep telling her that if she gets me one I'll stop complaining about our lack of dark skies.

Maybe I'll have better luck with the Digitalis planetarium. It's cheaper. However, I do suspect we'll have difficulty fitting it in the bonus room though.

My other option is to map out the section of sky I want on graph paper. Punch holes through the graph paper where the stars are then tack it to the ceiling and paint where the stars are.

One of the earliest planetariums was a dome with hols drilled in it in the positions of the stars. The light from outside shone through the holes- Creating the stars.

aurora
2007-Nov-12, 06:29 PM
If you have a wide screen TV, or a projection TV, or an LCD projector, maybe you could feed in your computer output. then you could run planetarium software on your computer (either commercial or freeware) and enjoy it that way.

Not the same thing as having a dome, but with a good imagination you could pretend it was a viewing port on a spaceship...

tdvance
2007-Nov-13, 06:45 PM
the LCD projector method would work (but expensive if you can't borrow or already have one).

You could also do the following--cheaper, but lots of work. Get a big, lots-of-stars planisphere or single all-sky (at least one hemisphere anyway) map--you don't want to take different pages of an atlas and try to match them up, projection distortion could keep that from working well (different pages may use slightly different projections)--but if it's already all on one page, it's ok. Either use a pencil or a transparency to draw or overlay a grid over the map. Use a pencil to faintly draw a scaled-up version of the grid on the ceiling. Then, use the grid to accurately plot the stars.

Incidentally, an early, temporary, and inaccurate "planetarium" was ordered by King George, the one Herschel wanted to name Uranus after. He was having a star party in his court, and it was a cloudy night. So, he had his servants put lanterns in the trees surrounded with shades punched with holes so the people could use their telescopes to look at the distant "stars". Hey there's Pleiades over there...oops, Pleiades fell out of the tree!

eugenek
2007-Nov-13, 10:46 PM
You could also do the following--cheaper, but lots of work. Get a big, lots-of-stars planisphere or single all-sky (at least one hemisphere anyway) map--you don't want to take different pages of an atlas and try to match them up, projection distortion could keep that from working well (different pages may use slightly different projections)--but if it's already all on one page, it's ok. Either use a pencil or a transparency to draw or overlay a grid over the map. Use a pencil to faintly draw a scaled-up version of the grid on the ceiling. Then, use the grid to accurately plot the stars.


Interesting idea. Unfortunately, I have a popcorn ceiling so drawing lines on it would be very difficult. I'm leaning toward what is probably way too much work. I'm going to plot out the stars on graph paper and punch a hole through the graph paper where each star is. The hole will be big enough so a toothpick with a dab of glow in the dark paint fits through it. I'll tack the graph paper to the ceiling and then begin toothpick marking each star one section at a time. Once a section is done I can remove that section's graph paper and work on each star in detail. Since each star will be plotted on the graph paper I'll know exactly which tiny dot is Vega and which one is which one is 13 Lyra. I'll want Vega to be a tad bit brighter.

I have a book called Starlist 2000 which has a list of quite a few stars. I believe it has everything up to about 6th magnitude plus some dimmer ones which are special in some way, such as Barnard's star. This make plotting the stars pretty easy since the information is all in one place.

The ceiling is about 16x14 feet and I've decided I want the sky between RA 16H and 22H and declination -60 to +60 to be up there. Hopefully, the distortion caused by going from 3D to 2D won't be too bad at the higher declinations.

I'll probably kink my neck doing this.

torque of the town
2007-Nov-14, 05:23 PM
Her only response was "no."

Have you told her that the radiation wavelength emitted by this equipment is known to reduce the ageing process
and is more effective that botox......

:whistle:

Delvo
2007-Nov-14, 06:41 PM
I've thought of installing a diffuse lighting system in my home, not to emulate the stars but just because I like the diffuse light from many tiny sources. (Think Christmas lights and the aura they generate.) Both of the methods I'd be choosing between would use little holes of one size or another drilled/punched through the ceiling surface, so they'd be easier to do with a tile ceiling than with a drywall ceiling, but possibly either way. And in both cases, the wires would be out of sight, above the ceiling material (drywall or tiles), so only the lights are visible below.

One method is a single light bulb or just a few, hidden in the wall or a closet or such, with fiberoptic wires for distribution to the various points on the ceiling (like some artificial Christmas trees with built-in fiberoptics on the branches leading down to a light bulb hidden in the "pot" at the bottom, where a rotating semitransparent color wheel keeps every light's colors changing).

The other method is simply using one or more string(s) of regular Christmas lights; you can get multiple-color strings or strings of just one color, especially white, blue, or frosty pale whitish-blue/bluish-white. Some of these now use LED lights instead of incandescent bulbs.

Either way, you just make the holes the size of the lights, run the wires over the top surface of the ceiling, stick the lights into the holes, and plug in someplace (visible or hidden, with a switch or without...). Turning it on or off at will is easy, cheap, and quiet, and can be done without tying up computer resources or requiring that any other device be on or off at the time. The only drawback is that it can't be changed very frequently or easily or change with time on its own. (This isn't an issue for me because I wouldn't want it to match the stars' patterns anyway.)