Jun 15, 2009

Improving Contrast with Black Scrim

After a couple years of doing the projection I've noticed that using a white sheet doesn't always work best in all conditions. For example, when it's still daylight out you will lose some of the contrast in the areas of the animation that should appear black. Since the sheet is white it will reflect some of the light coming in from outside the window. I tried hanging a black scrim material (basically a mesh) between the window and the white sheet to help darken the black areas. Since my projector is pretty bright it worked really well. Have a look at the video below to see the effect. Update: My BenQ projector has a brightness of 2200 lumens.

During dusk lighting conditions it improved the contrast quite a bit. Once it was dark out it didn't really change things much... in fact it brought the brightness down on the projection a tiny bit but it wasn't all that noticeable.


Update: Here's a picture of the black scrim material I used. I have no idea what it's called... I just picked out something from the fabric store that looked like it would work.


9 comments:

  1. Mark, what kind of scrim material did you use and how big can it get? Thanks
    -Victor

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  2. Victor, I'm not sure about what kind it is... have a look at the photo I just posted. I think it came in about a 4 foot width and the length was whatever you needed. I got it from Fabric Land in Calgary, Canada.

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  3. I've used a rear projection material and it works fantastic. Although it can be a little expense the results are great. Here is the link http://www.dazian.com/cgi-bin/page.pl?action=show_style&style_id=346&group_id=165&cat_id=50

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  4. What about using the Pepper's Ghost effect with this DVD? In essence, playing the DVD on a computer or TV, laying the monitor on its back and setting a piece of plexiglass over it and an angle. This is used to project an image that looks like a hologram, but would the same work with this DVD?

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  5. @Brighid -- A neighbor in San Diego used the plexiglass trick. It works -really- well!

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  6. That rear projection material is $60/yard !?!? Good lord. I'll stick with $3.99/yard stuff.

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  7. This year, I used Wax Paper for rear projection in my front window and it worked *amazingly* well. I just tore off window-height strips of generic store-brand wax paper and taped it to the inside of the window. What amazed me most was that even though it didn't look sharp on the inside of the house, it looked amazing on the outside (got a lot of feedback- everyone was wondering how I was able to get such a high quality image into my window). The wrinkles, misc rips, and overlap in the waxpaper also added some nice texture to the footage as well (I was sloppy putting it up).

    At $2 a roll, the price per square foot can't be beat (try it, you'll like it)!

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  8. I am interested in scrim projection-may I ask what the white sheet in your graphic does? I haven't seen that anywhere else when researching projecting onto scrim. Thanks!

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  9. Ahhh, thanks for the information, this was exactly what I needed. I see folks using white scrims, it's just to visible.

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