lets make an animated "crystal ball"

[White-Light]

Peep holes are too small. As for Gopro, I actually had a Hero3 White and sold it months ago. That could work. The problem is, and please correct me, that if the angle is less than 180 degrees, I have to move the lens and thus the projector further down from the bottom part of the globe so it can fill the whole globe, increasing the case height, maybe a bit too much to look nice with 120 degrees.
And there's also the issue with what to do with the stock pico lens, and how to find out how wide the fisheye aperture would have to be. My knowledge on lenses is really lacking.

There are several places that sell after market GoPro lens replacements as well as new original lens. They generally range from around $100 for an original to $250 for the very widest after market with a wide after market around $180-190.

I don't see why it won't work.
But what does SOMETHINGx mean? with that one its 0.21 and with the FlipEye its 2.0. What's the angle? 180 degrees like the FlipEye? Less? Confusing stuff. The page says "an approximate view angle of 183°". How does that translate to beam angle?

Because it's not technically a lens, it's a telephoto style adapter. For photography, you attach it to the front of an existing lens and then the focal length becomes 0.21x the original ie. 28mm becomes 5.88mm (28 x 0.21 = 5.88).

How it would work on its own I don't know. I can't see why it wouldn't work, but the exact angle is probably more difficult to predict when there's no base lens behind it. Could be a case of trial and error.

[mixedgas]

Candy shops and women's craft shops usually have the transparent globes..
I clearly hope Armenian women are not infected with the "crafting" disease like American women.
Huge shops exist here with nothing but expensive Kitsch... That costs them nothing to make.

Steve

[mixedgas]

Turn on and Focus the projector at infinity, place the pico lens in front of it. See what happens...

The pico lens looks like a 137' fisheye, it does not have the large "Frisbee disk" outer lens typical of a 180' degree fisheye.

Steve

[White-Light]

Don't know if acrylic will do or if the necks too wide, but:

A clear 14" acrylic dome your side of the pond, here:

http://www.amazon.com/American-3202-..._5582393011_61

There are also some smaller ones down to 4" diameter.


A 7.5" glass dome here (albeit hand blown so may not be perfectly round):

http://www.homedepot.com/p/Westingho...-203066064-_-N


A nice looking one on Ebay here:

http://www.ebay.com/itm/Clear-GLASS-...item3aaf5f17cd


4 slightly smoked glass 6" ones as a set:

http://www.ebay.com/itm/contemporary...item4d2243c6be


I'm sure I could find more, with more time, but at least that gives you something to go at.

[DanBarlow]

Acrylic medium, sealer, or clear coat with Matte finish, spray paint?

[White-Light]

I did a google search for you Dream a few days ago and the leading technique seems to be sandpaper to the outer surface! Opinions vary between 600 grit (medium) or 2,000 (very fine) but it appears from what I've read that if you want to avoid visible lines, then the fine sandpapers are the way to go using a circular motion. I also read some mention of applying heat with a hair dryer afterwards. I know you can use this to repair scratched plastics, but so far as I'm aware that's what it does, repair, in which case you might end up back at square one! Can't verify any of this though personally. My only experience of etched acryllic has been laser etched engraving which I've only ever seen done to flat surfaces. I would hazard a guess that commercially produced opaque / translucent acrylics are produced by additives to the acrylic mix rather than a post casting process but could be wrong.

The danger with trying to etch plastics with chemicals is that although there are chemicals that "mist" acrylic, many of them do so by damaging it eg I think cellulose thinners from memory of my own experiences, will mist and fine line surface crack plastics. They also make it brittle and degrade it though. There probably are safe ways, but if so, I haven't managed to turn anything up with a search.

Some people have tried painting these domes, but the trouble with plastics is you need a plasticiser first otherwise the flex will crack the paint off, and in any event, that's always a danger with spray coatings. You'd also need to bear in mind how any coating may react to heat from the projector given that the projector is in the base and it's a sealed dome - heat and possible expansion that is.

[White-Light]

That's interesting. Do you still have the link? The main reason I want the inner surface is to keep the outer surface smooth like a real crystal ball for aesthetics as well as so it won't get dirty quickly from dust getting trapped in the small holes. Well, and also so the light beam will not have to pass through some layer of transparent plastic before getting diffused, not sure if this is a problem.
Now if people sell some kind of non-flat, fine sandpaper head for a dremel I could try sanding the inner wall of the globe with that. Because I've never done this kind of thing I don't even know what I'm looking for.

Couldn't find the original links but here are some:

http://www.instructables.com/id/LED-...g-the-acrylic/

http://www.thebestcasescenario.com/f...osting-Acrylic

https://groups.google.com/forum/#!to...em/9FEn9qHlA-A

I very much doubt you'd be able to frost the internal surface evenly with a dremel.

While I agree that acetone degrades acrylic, I don't think for this it matters much. The dome doesn't have to be strong and acrylic is pretty strong and I only need a thin layer of 'degrading' to happen after which I'll let the acetone evaporate.
The only worry with this approach for me is how even it will be.

I'd be very careful about using acetone. It is mentioned in the links I found today though as a tried method by 1 person. He reported unevenness though

I agree. Although when these domes are screwed in some base or bolted they can hardly flex.

You will get some expansion with heat build up and this may or may not causes the paint to flake.

There's a frosting spray here for glass, unsure of how successful it is on acrylic although it does get mentioned a couple of times in the links in the 1st post:

https://www.doitbest.com/products/fr...sol?sku=796125