|
Post by Ron Walker on Apr 6, 2023 19:12:09 GMT -7
Posted by: Charlie Miller Mar 14 2012, 05:16 AM Hi folks. Hope all are well. Thought I'd post a mini update on my home-made "in line" optics for the video projector & fisheye system that Ken M et al have posted seminal thoughts and work about (sorry for tortured syntax!) A friend of mine (Jerry Swails) has helped by making a projector "holder", as seen in picture, that holds the projector vertically and allows for adjustment of the off-from-vertical angle to compensate for how the image comes out of the projector's lens. Also shown are the Peleng fisheye and that massive Rodenstock lens. I'm so proud of using stock PVC tubing, including a reducer that works well with the two lenses. Added to the reducer are a couple layers of large (4 inch?) PVC pipe sections that provide a means of mounting a flat and pivoting joint, which I happened to have in one of those junk boxes that we tend to accumulate over the decades. What's next is to make a vertical stand for the lens assembly so that it's positioned above the projector.
|
|
|
Post by Ron Walker on Apr 6, 2023 19:14:15 GMT -7
Posted by: moonmagic Mar 14 2012, 07:46 AM Charlie- I hardly know anything about this new age of digital planetariums, but of course that does not inhibit me in the slightest from adding a reply...
This is all really very clever. It seems that everyone (yourself included) that is on this forum has skills to "make things" that I've never had. I certainly have not kept up with the new age of digital projection.
The person who made the projector holder for you made sure that it was to say the least, sturdy!
The use of the PVC material for the lense seems great.
Mainly, I just wanted you to know that (if only in spirit) that I am still here (albeit in the background) supporting your efforts. mm
|
|
|
Post by Ron Walker on Apr 6, 2023 19:14:42 GMT -7
Posted by: Charlie Miller Mar 14 2012, 07:55 AM Thanks mm,
Yeah, the twisted brackets are pretty cool (!)
Sad thing is... that this fixture will only be a "proof of concept" as my projector is rather low-resolution (1/4 high def) and will project a pretty crude sky. I plan on just having this thing mocked-up and on a table top as a "what's next?" type artifact.
One thing that surprises me is how hard it can be to match up with the "right" people in my community. From my 50+ yr perspective, seems like we've all gotten a bit ossified, with a "can't do" attitude.... or perhaps more accurately stated, "bureaucratic" or "business model" mindset when it comes to popularizing science. That's likely not so for the really major institutions, but the mid-sized science centers seem a bit stereotypic and predictable.
I think I'm onto some good notions (for a revised depiction of science), but it is hard to sell the idea. I think this is due, in part, to a kind of "settleness" or stratification of things in our society. I'm not expressing myself worth a darn here.
|
|
|
Post by Ron Walker on Apr 6, 2023 19:15:07 GMT -7
Posted by: Ken Miller Mar 14 2012, 09:44 AM Charlie:
A couple of things:
I have been mounting the projectors horizontally and using a telescope diagonal to shift the image to vertical. This is because of advice that I got that suggested that vertical mounting would encourage dust collection on the imaging surfaces inside the projector. Also, I think it makes it easier to mount the lens assembly when the projector is sitting horizontally. As a side note, I am using a PVC lens mounting assembly for the "straight-through" projection into the vertical dome for the Maker Faire.
The projector is a critical component of the assembly. I have not found a standard lower resolution projector that is compatable with the lens assembly that you are using. It is a problem because these are shorter-throw projectors with a beam that spreads out in too short a distance to allow capture of the full image by the external optics. If you have success with your projector, please let me know. It's really hard to tell if a particular projector will work until you try it. The published specs can be misleading. I can personally testify that the Optoma TX 1080 and the Dell 7609WU work well, and there are a few additional projectors that have been reported to work by others.
|
|
|
Post by Ron Walker on Apr 6, 2023 19:16:02 GMT -7
Posted by: Ron Walker Mar 14 2012, 10:02 AM QUOTE(Charlie Miller @ Mar 14 2012, 05:21 AM) * Here's a close-up photo of the PVC reducer and the 2 layers of pipe section added to provide a flat mounting surface.
Does anyone have hints about sealing the PVC so it won't degrade over time? I was a little surprised to see that the "insides" of the PVC is made (seemingly) of a more porous core (see color change in x-sections).
I don't think PVC in made of more then one type of plastic. It is just injection molded out of one type of material.
Unless you leave it out in the Sun all day for 20 or 30 years, I don't think you will have much of a problem. Actually, I do have PVC pipe that has been out in the Sun an elements and has never been painted for over 30 years and is just fine. I would however spray paint the interior a flat black to help with reflections which tend to "gray out" the projections. Lightly sand any surface that you plan to paint so that the material will bond and not flake off when dry.
I am also not at all sure if standing the projector on end will be good for it in the long run. I've heard horror stories of bulbs exploding and parts of optical blocks melting because severe angling of projectors affect the cooling air flow. Mounting it 90 degrees could be a problem. I have seen planetarium video projectors mounted vertically but I would think they are not just "off the shelf" models with a different lens attached. Something to think about.
|
|
|
Post by Ron Walker on Apr 6, 2023 19:16:51 GMT -7
Posted by: Ken Miller Mar 14 2012, 10:29 AM An alternate to painting the inside of the PVC is to use black construction paper as a liner. I painted mine flat black, but I'm about to try the black paper to make it a little better. The paint was not as flat black as I would like, and there are some reflecting edges.
|
|
|
Post by Ron Walker on Apr 6, 2023 19:18:11 GMT -7
Posted by: Ken Miller May 22 2012, 08:13 AM I'm going to post the results of the Maker Faire over in this part of the forum, so as to not distract from the amazing stuff that Ron Walker is doing with his dome construction.
It was a very hectic weekend. I had hundreds of people stop and spend time considering the planetarium building concepts at my indoor exhibit (thousands more walked by and were briefly entertained by what they saw). We had thousands of people take advantage of the outdoor solar viewing activity, and hundreds that stayed around after the official closing of the Faire to view the eclipse. I think we made a big impact on the people that stopped to spend time with us. We ended up with a team of 17 people that helped set up and run the two exhibits, and we needed every one of them. I'm especially proud of my wife and step daughter for taking charge of the solar exhibit, and making it work as well as it did.
I'll be posting pictures here when I find some time.
|
|
|
Post by Ron Walker on Apr 6, 2023 19:18:33 GMT -7
Posted by: Charlie Miller May 22 2012, 08:23 AM QUOTE(Ken Miller @ May 22 2012, 10:13 AM) * I'm going to post the results of the Maker Faire...
Ken, I am happy to hear of your success. Yea!
|
|
|
Post by Ron Walker on Apr 6, 2023 19:19:03 GMT -7
Posted by: Charlie Miller May 22 2012, 08:27 AM QUOTE(Ken Miller @ Mar 14 2012, 12:29 PM) * An alternate to painting the inside of the PVC is to use black construction paper as a liner. I painted mine flat black, but I'm about to try the black paper to make it a little better. The paint was not as flat black as I would like, and there are some reflecting edges.
Another alternative that I like is the use of black fabric-coated paper, such as those you can get at those, uh, girly shops (okay... scrap-booking shops). The paper I like has very short "nap" black fabric glued to paper backing, typically sold in the 12x12 inch scrap-booking squares. Eliminates the "fun" of painting a narrow tube used for planet projectors, arrow pointers, and the like.
|
|
|
Post by Ron Walker on Apr 6, 2023 19:19:24 GMT -7
Posted by: Charlie Miller May 22 2012, 08:39 AM QUOTE(Ron Walker @ Mar 14 2012, 12:02 PM) * I don't think PVC in made of more then one type of plastic. It is just injection molded out of one type of material.
Unless you leave it out in the Sun all day for 20 or 30 years, I don't think you will have much of a problem. Actually, I do have PVC pipe that has been out in the Sun an elements and has never been painted for over 30 years and is just fine. I would however spray paint the interior a flat black to help with reflections which tend to "gray out" the projections. Lightly sand any surface that you plan to paint so that the material will bond and not flake off when dry.
I am also not at all sure if standing the projector on end will be good for it in the long run. I've heard horror stories of bulbs exploding and parts of optical blocks melting because severe angling of projectors affect the cooling air flow. Mounting it 90 degrees could be a problem. I have seen planetarium video projectors mounted vertically but I would think they are not just "off the shelf" models with a different lens attached. Something to think about.
I hope that doesn't happen. I was thinking of augmenting the air flow with a mini muffin fan.
|
|
|
Post by Ron Walker on Apr 6, 2023 19:21:07 GMT -7
Posted by: Ken Miller May 30 2012, 08:57 PM At the Maker Faire "Planetariums as a Hobby" exhibit.
|
|
|
Post by Ron Walker on Apr 6, 2023 19:25:49 GMT -7
Posted by: Ken Miller May 30 2012, 09:00 PM At the Maker Faire "Solar Plaza" exhibit.
|
|
|
Post by Ron Walker on Apr 6, 2023 19:29:43 GMT -7
Posted by: Ken Miller May 30 2012, 09:03 PM Setting up the vertical dome at the Maker Faire.
|
|
|
Post by Ron Walker on Apr 6, 2023 19:32:27 GMT -7
Posted by: Ken Miller May 30 2012, 09:06 PM Solar eclipse under way at the Maker Faire. Viewed in the Sunspotter solar viewer.
|
|
|
Post by Ron Walker on Apr 6, 2023 19:34:59 GMT -7
Posted by: Ken Miller May 30 2012, 09:13 PM Information kiosk at the Maker Fair "Solar Plaza". Presided over by a clone of Camilla Corona from the SDO camilla-corona-sdo.blogspot.com/We had a crew of 17 people manning the Solar Plaza and Planetariums as a Hobby exhibits over the course of the weekend. Everyone had a blast and wants to do it again next year. We had thousands of visitors that enjoyed the exhibits, and a dozens that we really made a major connection with. I had several people tell me that we had the best exhibits at the Faire. There was a total of about 900 exhibits at the Faire. Total attendance for the two days was 120,000.
|
|