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Lens Hood
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Tip from TPro: Many have reported
internal reflections causing halos around bright objects (lenticular-fresnel halo), and
hot spots on the screen. To reduce these reflections, there seems to be two things that
work.
One is lining the entire video cavity (behind the screen) with Duvetyne fabric... a
blacker than black cloth that does not reflect light at all; or the other option is to
build a lens hood that blocks the three lenses from having direct view of the screen.
Since most reported the lens hood as having the most positive effect, I opted for this
"lay-in" hood that is easily removable. The goal of the lens hood is to prevent
light reflected from the screen from re-entering the lens system, while still letting the
light from the lenses reach the mirror."
He highly recommends this reversible mod!
To find out how he did it for his set, click here.
Got a Toshiba TW40? Here's the info for building one
for it.
Tip from Matt Kasprzak: For those of
you who were interested, I took down the measurements of my mockup lens hood for the
TW40X81. I encourage everyone to build a mockup prior to creating a final version,
especially if you've purchased special materials and fabrics to cover it with (like I
did). That way, you can tweak it to perfection before commiting to the final product.
Please refer to TPro's (Timmy's)
instructions for pictures of the pieces that make up the hood, as I will refer to his
numbering scheme for these measurements. Without further ado:
Piece #1: 23.5" x 11.5" (Base piece)
Piece #2: 15.75" x 5", 2.5" back from mirror edge, centered
Piece #3: 7.5" x 4" (Two pieces)
Piece #4: 15.75" x 4"
Both #3 pieces extend from the back of the base cutout to the mirror edge of the base
piece.
Piece #2 was adhered perfectly to the top front corner of the #3 pieces, extended
through the cutout of the base piece, and allowed to butt up against the cutout edge.
To get the curved cuts in both #3 pieces, put the hood in place (it fits snugly in the
depressed cavity surrounding the lenses) and observe where the red and blue light hits the
inside of each side. When all was done, the bottom of the cutout was 1.25" above the
base, about 4" wide, and about 0.75" from piece #2 and piece #4. From there, I
angled my cut upwards to almost a point.
Note: My cut was not a perfect curve, but rather three straight cuts. (Hope that makes
sense) I've yet to make my final product, but I am *very* happy with the results,
and I didn't even get to the inside of the light box yet. |
