Hello Likay,Likay wrote:A question: I plan just to get two pairs of dolby glasses to use as filters for a start (i've heard the aperture is small though). inspite of that, will these to some degree show what to expect finally?
Two pairs of glasses will be enough for you to to start with. My present setup uses flat filters from Dolby but I see very little difference compared to my previous setup with lenses from glasses. It is a little better in the corners as I have very short throw projectors (1.5:1).
History of my setups:
Linear polars => Dolby from glasses => Dolby flat filters
In case #2, the aperture of the lens is wide enough to let the full beam go through, but a little wider would have been better in my case (short throw). Thats one of the reasons why I ordered real flat filters.
Opening in plastic frame: 38 x 32 mm
With this setup you will have everything to make your decision. If you want to play videos, download my LUT tables and try them. If you are using standard UHP lamps, they would work well. If not, you can play with my calibration routines to make your own tables.
Cost: A set of two flat filters (left and right) is listed at 320$ (Dolby Price List).I have two 3-lcd-panel projectors and if successful with the glasses test i think i can mod these(devilish idea with good chance of permanent failure...
) by replacing the internal original mirrors with infitec dichroic ones if they have such stuffs. 3 mirrors will be needed for each pj in that case and i have no idea yet of the eventual (probably too much) cost for this.
Would have been a good idea but...
Remember that an interference filter is a glass plate with several (~50) vacuum deposited layers. Spacing beetween layers is critical as this spacing defines which wavelength go through and which is reflected. If the beam angle is not 90 degrees, spacing increases, shifting the values. 10 degrees is enough to let crosstalk appear. Aren't the mirrors in a LCD projector 45 degrees ?
The best place to put the filter inside a projector is between the IR dichroic filter and the block of panels (before/after the fresnel lens I dont know).
Bad news for me: I just happened to open one of my projectors this afternoon.
Everything is pack up very tight and there is absolutely no room available to insert the filter, unless I take apart everything, that I do not want. I dont want to disassemble/reassemble the whole thing and say: Hey, I have those 2 screws left....
)
Too bad one can see 2 slits (one vertical, one horizontal), but I think they are here for air flowing, not for possible filters.
I thought of putting the filter in the lamp itself, building some kind of sliders to set the filter IN/OUT. That would have been smart, as this would not have impaired the projector's waranty. But:
1. In my case, they are smaller (50x50mm) than the lamp opening (60x55mm)
2. As they are highly reflective, they should not be put before the IR dichroic filter which belong to the projector.
So my filters will stay outside. One thing I could do is moving the setup farther away from the screen and zoom less. We'll see...
The lamp compartment, the lamp and the IR filter (angled). Right behind, we can see the fresnell lens.
R2 G2 B2 and gaps are definitely lost.
I agree.
