Yesterday and last night we tested more films for the projection screen facing Hennepin Ave. There were several candidates. One from a Kimoto a japanese company, a 3M film, a standard rear projection fabric by Da-Lite as well as their Holo Screen and a version of their standard fabric applied to plexiglass.

The 3M film is not an optical film just a vinyl film meant to simulate frosting. Surprisingly in combination with the frosting that is already on the glass we get pretty good light dispersion. There are still hotspots on this during the day but they are not bad. This solution has the advantage of being cheap, fast to install and less obtrusive to the curtain wall because it adheres directly to the glass. It also comes in a variety of colors and opacities so we can better match the color of the glass.

The Kimoto film looked very bright. It dispersed the light better than the 3M film but not as good as the Da-Lite screens. Being a film that could be applied to the film this has most of the same advantages of the 3M film. Unfortunately they can not manufacture this in a 6ft width so our window would have seams in it; also this manufacturer is in Japan and not is not carried by anyone locally so it would take at least a week for delivery. There are still hotspots in this film but they are not very noticable.

The 3 Da-Lite screens are manufactured to be used for rear projection. The heavy gray screen gave us the sharpest picture and the greatest viewing angle. It was also had the best viewing angle during the day with a lot of ambient light. As a product of its light dispersion it actually looked the dimmest. The Da-Lite rep said they have a fabric that would be twice as bright with a smaller viewing angle. The brighter fabric would have the same physical properties (ie opaque and gray) as the fabric we have now. The sample of the rear projection fabric on plexi has the same light dispersion properties as the heavy gray screen but in a rigid application. The Holo Screen is the most transparent screen during the day. It disperses the light well at night and has a high light gain. It does not perform well when projecting on it during the day and it does not read very well from the inside at night. It could be used in a rigid application with plexi. It also has the disadvantage of being by far the most expensive and taking the longest to order (about 5 weeks).

I took some videos at night: Night1,Night2

and during the day:Day1,Day2

The table got an update recently. It has audio now. It has really really loud audio now in a space with a lot of echoes. Since we have to tweak movies individually after we hear them in the space we are going to add a node for volume to the XML describing each movie. We are still working out solutions to deal multiple sound sources being open at once since there is a lot of sound overlap.

The cool part now and why i titled the post Ghost Hand is the hand in the table now ghosts your actual movements. It is no longer a one size fits all mannequin hand. Everyone who walks by seems to think this is “the coolest thing ever”. Its hard to take pictures of the screen but that didn’t stop me.

And the final update is i changed the font to Univers because the hinting seemed better. If you had been trying to read the type before you would notice the difference. I would have liked to use Avenir to match our new identity system but that font doesn’t seem to be hinted very well for rendering on screen, or else it didn’t survive my conversion to True Type intact.

Still a long way to go but this is progress.

Last night we were able to do a test with actual rear projection fabric taped to the rear of the front window. It looked great. I took some video but they really don’t do justice to how much nicer it was. There is only one pane of glass with the fabric on it in all the shots. Usually it is easy to see, if not look for the blue tape holding it up.

Viewing from the front you can see that the film evens out the bright spots although the image looks a little dimmer over all. It is still bright enough to read 8 inch type from the road. You might also notice the bouncing off the back mullions is minimized.

The difference is much more apparent at steeper viewing angles. With the film you can see read the sign from the stoplight even during the day. At night it is more pronounced.

From the inside during the day you can see this “cheaper” fabric is actually quite opaque but it does show the projection decently even in near full light. At night in the hallway you can see that with the fabric we have the option of showing colors and lighter backgrounds that were not options before.

Outside the screens is more apparent when we use a large field of white but also our pedestrian audience should be able to read the signage much better.

There was still some concern about how opaque the fabric we tested was.

**Update**

I did some looking into a local manufacturer and found out 3M does make something that looks nice. In theory anyway.

The Vikuiti product line has rear projection screen material that looks pretty heavy duty but there is also a wide array of Light enhancing films but according to their online info it hasn’t been used for this type of application yet.

This week we got control of the lighting behind the projected signs on our expansion. The screen still looks splotchy but now it is not faded out on top. There is some crazy bounce back that is more noticable when the lights are dimmer. You can see from this movie the light bounces back noticably off the clear glass and again of the frosted glass giving us this rather interesting pattern on the back wall. I think that is something we are going to have to embrace as a quality not an unintended side effect. Also notice we thinner type makes these weird patterns on the mullions. Andrew mentioned the mullions were like a light show on their own.

Certain colors show up better than others due to the tinting on the glass. Looks like yellow and pink show up best but bright bright green looks pretty good too. Blues and photographic images look very weak and muddy (yes that last movie is an image of 1 Groveland projected on the new building).

You can see the type looks better but the weird bouncing we saw on the mullions is visible from the outside and the light from the chadeliers hanging inside interferes with the projectors making a new dead spot in the middle of the image.

Sunday we saw the table for the first time with actual hand projections (in the prototype, there was a fixed ‘claw’ for grabbing icons). The projections were rough around the edges and pretty finicky when it came to picking up interface elements, but still very cool.

There’s a lot of remaining work to get the table where we want it before the opening. We’ve identified features that may not be implemented by April 16. Disappointing but I’d rather have all visible elements fully functional before finishing pieces that could be added as enhancements later.

Marek using the table

A very rough version of the interface. Images represent works in the collection, mostly on view, and the figures (the little guys in a row on the left) will walk around the work. Each figure has a different question for a work. Both work and figures are “grabable”. When dropped on one another, they open a feature that is the response to the question.

Lousy picture but you get a sense of an open feature. In the bottom example, the question is “How does Stan Brakhage see the world?” The response includes a video excerpt from a talk with Brakhage at the Walker in 1999. Up top is a feature on how Chuck Close uses photography in his work.

The table wrapped pending more construction in the space