4 Projector blend on a sphere

[SourceChild]

I have done a few spheres of different sizes. I personally prefer longer throw lenses since the further the projector is, the less proportional the optical distortion. Nevertheless, I've done a few 0.8s as well.

If you want to blend an entire sphere you'll need to hit it from six projectors (4 sides, top, and bottom). I did part of this once (no top, just bottom).

The content creation was actually the hard part.

The content creation model was card board box style with a center square and four squares on each side of it which folded up. It was actually pretty tough and the innovation was applauded but I would have preferred setting for something much simpler.

Just try doing a linear wrap with four. If you absolutely must do full coverage, contact me and I'll give a little more detail.

I also strongly suggest trying a prototype first with a small sphere and some low power projectors somewhere off site.

[usami]

Hi

Thanks for suggestion.

In case of such an image? (see below)

http://obscuradigital.com/work/domes/aol_ces_las_vegas

In such a projection, will it be the best solution to use five projectors?
It is an adjustment of a very difficult keystone.



Mileruntech.com
Tokyo Japan

Usami

[SourceChild]

Hey Usami,

I think we did not understand you correctly. We believed you were to project on to outside of sphere. The picture you show is inside of sphere.

They use custom technology to create the sphere. If you wanted to use Catalyst to do the same thing I can imagine a way to do it but would take at least 7-8 projectors and at least 2 Catalyst machines.

[joeltcarontx]

I am wanting to use a catalyst to project onto a sphere and I was wondering what people are using for the actual projection surface/structure. My project would only require about 180 degrees of coverage. Hopefully, I can do it with only 2-3 projectors.

Thanks!
Joel Caron

[samsc]

I am wanting to use a catalyst to project onto a sphere and I was wondering what people are using for the actual projection surface/structure. My project would only require about 180 degrees of coverage. Hopefully, I can do it with only 2-3 projectors.

Thanks!
Joel Caron

blending on spheres is tricky.
i believe they need very specific geometry adjustment and much more complex blending - but i could be wrong-

i know several people have done spheres - but i dont know the conditions.

i wrote some stuff for internal projection inside spheres this year - for wide angle projection

[SourceChild]

I am wanting to use a catalyst to project onto a sphere and I was wondering what people are using for the actual projection surface/structure. My project would only require about 180 degrees of coverage. Hopefully, I can do it with only 2-3 projectors.

Thanks!
Joel Caron

I have done exactly what you are saying. I used two medium throw projectors with a 50% blend. The sphere was over the stage and we projected up from two poles on each side of the stage apron.

The location of the projectors was required to create an even field for the whole audience. The angles were about 40 degrees of axis (80 degrees between).

The extreme blend was to make sure that the spill off on either side was hidden. It took a lot of time to overlay the blend and apply the bezier distortion to get the image to line up correctly but eventually looked very very good.

In all honesty, you can do the same thing with a single long throw projector and have nominal uncorrectable distortion. In fact, in tests, a single projector looked good up to a 120 degree viewing angle.

We used weather balloons inside of a custom sewn cover.

Try a test on your own with something like a 2k projector on a beach ball in your shop. It's a quick easy way to test your thoughts.

[joeltcarontx]

Todd,

were the projectors at the same height as the sphere or are they projecting from the ground?

Would you suggest either hitting the sphere with two 16K projectors (They are large Digital Projections, I cant really fly them) from the ground with short throw lens (less than .8) or a 15K LCD with a long throw lens almost straight on?

I ended up purchasing a 12' PVC advertising balloon. I see you are out of Austin, you interested in coming to Dallas to help on the load in?

I appreciate your advice/help.

-Joel

[samsc]

thanks todd-


i havent done one of these myself - i know you did-