Best paint treatment for a projection surface?

[NicoDanger]

Hey there,

I am working on content and programming for a show that goes up in a couple months time. It involves mapping projections onto a series of flat panels, which are being custom-fabricated. The other day I was talking to the guy who's in charge of the build and he asked me how I wanted it painted, to which I replied 'flat white.' Then I started thinking, what are my other options? Does anyone care to advise about the best treatments for flat surfaces to accept projections? I should mention that we'll have quite a lot of lumens to play with.

The other thing to take into consideration, however, is the fact that we'll also have a cyclorama upstage. So theoretically the panels and the cyclorama ought to be treated as similarly as possible so there's not a discrepancy between the two.

I appreciate any input...

Thanks,
Nick

 

[techieman33]

They make paints specifically designed to be used as projector surfaces, a google search for projection screen paint will give you lots of results.

 

[josh88]

Screen Goo Projection Screen Paint from Rose Brand

Screen Goo would be one example.

 

[NicoDanger]

Yeah, I've seen Screen Goo online before. I guess I'm unclear on exactly what the benefit would be...

 

[Footer]

Yeah, I've seen Screen Goo online before. I guess I'm unclear on exactly what the benefit would be...

Screens are all about reflected light. With a crappy screen, you will be wasting lumens. Flat white reflects very little. I would at least go with a gloss if you are just going to go with regular paint. Now, my preferance would be to go with a reflective fabric meant to take projection. A 10k projector aimed at a flat surface is going to look like a 5k or less.

 

[ruinexplorer]

Depending on what your content, white surfaces are not the best for contrast. Often times, designers will choose a grey surface to enhance the contrast in their projections to add richness and depth. Either way, I would choose something like Screen Goo mentioned previously as it has additives which will give you a better image. If your image is spanning across the wall and the cyc, you will not be able to match the image effectively.

 

[NicoDanger]

Screens are all about reflected light. With a crappy screen, you will be wasting lumens. Flat white reflects very little. I would at least go with a gloss if you are just going to go with regular paint. Now, my preferance would be to go with a reflective fabric meant to take projection. A 10k projector aimed at a flat surface is going to look like a 5k or less.

With a gloss coat won't there be a hot spot in the center of the surface? Or is there a particular breed of gloss paint to use (I'm assuming the answer here is Screen Goo)...?

 

[NicoDanger]

The Cyc and the Panels are two different surfaces fed by two different machines. The content is all formatted accordingly but the two will be playing simultaneously. However, I will have separate color control for the two.

As far as the gray is concerned, do you have a recommendation as far as which shade/brand exactly to use? My panel-based structure will be something like 50' wide, covered by two Barco 20k's. Two additional units for the cyc...

 

[museav]

Screen Goo and paint are both very dependent on the preparation of the surface and the application. My view is that with either of those your only practical option is to try it and adjust as necessary. You can find quite a few discussions regarding different paints on some home theater forums but keep in mind that they are addressing home theater applications where you typically have a limited audience area and good lighting control.

There are typically several factors to consider with screen materials. One is the gain or the amount of light a viewer sees compared to the light hitting the screen surface. Often related to that is viewing angle or how the reflected light falls off off axis, typically higher gain screens have narrower viewing angles and greater drop off off axis while wide viewing angle screens have lower gain. Another is the effect on image contrast that ruinexplorer noted. There are also secondary considerations such as potential hot spotting, washability, flammability and so on.

My experience is that people often neglect the viewing angle aspect, especially when dealing with wide or fan shaped rooms. It also can get overlooked when you start dealing with 'screen' surfaces that may not be perpendicular to the audience and/or the projector.

Lighting is another factor to consider, what are the chances that you will have the exact same lighting in terms of level and color hitting every bit of every projection surface? Even if you used the exact same material for the flats and cyc, would the ambient lighting conditions really be the same on both?

 

[NicoDanger]

The plan for the lighting is to light everything downstage of the projection surfaces from either overhead or from the side so there is as little spillage as possible onto our panels. However, I am well aware that light bounces around and it's impossible to keep totally free from contamination. So in answer to your question, no, the ambient lighting conditions will not be exactly the same but hopefully they will be close.

As far as viewing angle is concerned, the room is pretty wide so I think a matte finish (lower gain) is probably the way to go. The good news is that it's looking like all of the panels will be perpendicular to the projection, as opposed to being spun on angles or whatever.

I am assuming if I were to use gray paint on the panels I would then want a matching gray cyclorama, correct?

Thanks very much for this helpful feedback!

 

[doctorhandshake]

FWIW, I've prepared several surfaces including drywall and canvas with FP Screen Goo and had excellent results. The 'digital grey' variety yields good contrast, diminishes hotspotting, and reduces glare from incidental light.

NB It's a bit finicky to apply and I recommend the primer. If you're dealing with 50' wide of surface (not sure how tall), that could get pretty pricey quick as well, although cheaper than FP fabric at that size...

 

[jbrem003]

I have also had good success with Paint on Screen - Projector Screen Paint their highest gain paint allows for 3D visualization but requires knowledge and skill for operating a paint sprayer. All their other paints have rollon application. Its a little more affordable than screen goo and I've aways had good results. The one thing i always default to is how much light i want to reflect, projector or ambient. The higher the gain the more reflectivity, from all light sources. If i can control all my ambient light and completely blackout the space, then ill use the highest gain i can afford. If theres a lot of light spill, then it becomes a tradeoff. How much direct light do i want reflected from the projector vs. how much can i handle from ambient sources.

 

[museav]

I have also had good success with Paint on Screen - Projector Screen Paint their highest gain paint allows for 3D visualization but requires knowledge and skill for operating a paint sprayer. All their other paints have rollon application. Its a little more affordable than screen goo and I've aways had good results. The one thing i always default to is how much light i want to reflect, projector or ambient. The higher the gain the more reflectivity, from all light sources. If i can control all my ambient light and completely blackout the space, then ill use the highest gain i can afford. If theres a lot of light spill, then it becomes a tradeoff. How much direct light do i want reflected from the projector vs. how much can i handle from ambient sources.

That actually seems a good example of my earlier point as the product information for that product discusses gain but only as a single number, assumed to be the gain on-axis. I could not find any information addressing gain off axis, half-gain angles or viewing angles. That does not make it a bad product, however it does make it difficult to address during design or to assess how well it fits different applications.

The information on https://www.paintonscreen.com/cgi-bin/store/store.pl actually seems to indicate that the darker surface/higher contrast versions provide greater gain, which is counterintuitive and makes me wonder what they are actually measuring and how they are measuring it.