[ANSWERED] Question about minimizing projector light bleed

DillTheKraut

How can I reduce the leaking light?

If the issue comes from the residual light as it is very likely, you probably can't. It is a construction related hardware issue. On modern laser projectors you can stepless adjust the light source intensity. Therefor you could balance between picture brightness and backlight (residual light) intensity.
Conventional light bulbs in old projectors always have the full light power level. You can't lower this with the standard brightness level setting, as this only relates to the video input signals (source) brightness, not the 'backlight' power (Which is kind of the same like the backlight level in some LCD TVs). Though some bigger projectors does have a physical iris for the dynamic brightness feature. On some you can adjust the general light intensity with it.

As I wrote, if you move to the bigger projection, this issue will be less intense there.

dbini

@tifftiff

If you still have an issue with the black background showing up when projecting at full size, the EB-G5600 has Eco Mode, which drops the output down to 3600 Lumens, which may help.

DusX

Another option, since it seems you may have more light than you require, you could change the projection surface. Likely you are looking at a white surface (wall) for projection, but if you make the wall mid grey, it will consume more of the light.

Try your projection test on a piece of black construction paper and compare.

DillTheKraut

@dusx said:

<p>Another option, since it seems you may have more light than you require, you could change the projection surface. Likely you are looking at a white surface (wall) for projection, but if you make the wall mid grey, it will consume more of the light.</p><p>Try your projection test on a piece of black construction paper and compare.</p>

That's a very good suggestion. There are special projection screens which are black on purpose. With a black background, you get a deeper contrast, especially in a surroundings which are not perfectly dark. E.g. with a lot of ambient or even direct light to the screen. A white screen reflects more of the ambient light, which makes the dark part in the projection brighter. With a darker screen you can compensate this. But you might need more power to push the bright parts of the picture.

TiffTiff

@dbini thank you! that's the thing, I will be working in a pitch black space and every light 'leakage' is bad. I have added an analog mapping, without subtracted center circle as it's pretty difficult. But it looks already better this way.

TiffTiff

@skulpture thank you!!!

TiffTiff

@dillthekraut thank you! I have added a physical map and will probably use some kind of gobo or iris in the end

TiffTiff

@dbini thanks! tried eco and it's better!!!

TiffTiff

@dusx thank you! yes, black background helps a lot

dbini

@tifftiff

your physical mask looks good, but you might want to test it over a longer time - as the projector warms up it might soften the glue on the tape, leading to some comedy sagging. 4500 lumens might also warm up the mask quite a lot - be careful you are not creating a fire risk.