Originally Posted by Plasma54321
I assume the bracket extention upwards from the light is for a center speaker?
Your wall seems quite white or neutral in the photo.
That is because the filter is doing its job. Here is a reference showing the colour of the paint with sunlight.
Did the filter sheets go inside your clear tube?
Hope this shot better explains it.
The filter is attached to the top of the visor and then slides inside the hood. I can open or close the apeture of the light by adjusting the visor with a twist of the end-cap.
How did you arrive at the correct amount of light luminance? Did you use the colorimeter to measure or eye-ball it?
I think that is the real benefit of using a fluorescent tube with a hood + a little bit of distance between the display and the wall. You get to control how the light spreads. The hotspot (spectral highlight) that the tube creates is far much hotter than the 10% target we are going for. The hood allows you to contain the hotspot within the area of the wall that the TV is obscuring, so from the viewing position, you are only seeing the drop-off, which gets progressively dimmer as it spreads out.
The filter did cut down some of the light's intensity, but it wasn't enough to drop below the minimum I required.
I don't understand the process that you used for selecting the filter? Measure reflected wall color then if too much Green get a green filter? I'm stumped.
You have to measure the light directly, then measure wall being illuminated by that light. When you compare these two measurements, you'll see how much deviation the light is from D65 and how much the wall reflection is from it.
Once you know the difference between these two, you can calculate a filter that will correct it.
This is the direct measurement of my tube
6418 is fairly close to the target of 6500 that we are looking for.
This measurement is the reflection from the wall
Not great. So I have a colour temperture of 5375 that I want to make into 6500. The perfect filter would be one that cuts red and green by the right amount to bring them both down to meet the blue. But the perfect filter (which would be a cyan colour) doesn't exist commercially.
So the best compromise ended up being the CT 1/8 blue which I calculated would reduce the excessive red.
And this is the end result.
So its not 6500, but its an improvement over 5375, which was visibly too warm.
I could layer a green filter over the blue one (to create cyan), but I calculated that it would kill my luminance and the light output would no longer be effective. Not worth the payoff. I'm more than happy with it. I ran it for over a year without the filter and I could always tell it was too red. Now, its very neutral and I don't stare at it thinking to myself that it needs more blue.