I don't have pictures but here is what I did for my constant area screen.
4 8' 1x4" boards
3-4 yards of black out fabric
1 1/4" 2 foot by 4 foot panel
manual staple gun (I think load with 1/2" staples)
3/4" phillips wood screws (~40~ or so of them)
hand held jig saw
1 8'x4' 1/4" plywood sheet
6-7 yards of black cotton material
some more of the 3/4" screws
packing tape (get the good stuff)
hand held jig saw
Ok, I first cut 2 of the 1"x4" boards to the width I wanted. Then I determined what I need for height, and cut 3 vertical braces, out of the remaining 2 boards. Then I took the 1/4" plywood sheet, and cut 4 1'x1' triangles (well first a 1'x1' square, then cut that at a angle to make two triangles), and two keystones 1 foot long and 4" on the short side of keystone, and about 10" on the long side. I laid out the 1x4 boards and measured the diaganol's for or five times until I was sure the frame was square. The the triangle quater inch pieces were attached to the four corners of the frame, while the two keystones were used to provide attachment for the center vertical brace. While attaching each piece I kept measuring the diangonal's of the frame, making sure it was square. Then I laid it on its back, and lined up the balckout material. I made sure to buy extra in case any part of the material had any blemishs. Ok, next we cut it about 3inchs short of the width of the frame. Then came the fun part, stapling! The staples were attached to the FRONT of the frame, becuase the masking coverd those up, but we will get to that later. We started with the staples in the middle with one or two staples on both sides and top and bottom. We made sure to pull the fabric tight as we did that. From there, we worked to the corners, with just 2-4 staples at a time in each direction and then rotating to the other side of the screen. So it was like this; pulling-stapling-rotate-pulling-stapling-rotate etc. When we got to the corners we were like "oh my, are those waves/wrinkles gonna disappear, or did we not pull tight enuff?!?". Don't worry the last few pulls and staples got rid of every wave/wrinkle the fabric had. We then hung the frame off some 2x4 fours, and made sure it was level. Those 2x4's are attached to set of industrail shevels, but that is a story for another time.
Ok now for the masking. We went to the home depot, and had them cut the full 1/4" sheet into four 6" wide panels (yes we have lots left over). We wanted 4 inch, but they said all they would do is 6"! We cut the length at home to what we needed. We cut the bottom panel so its the width of our 2:35 viewable image. This then had some black fabric taped to its A grade side, that we had preped with a paper towel rub down, which was done to get most of the saw dust off so the tape would stick. Ok, with fabric taped to the board, and the fabric sticking out the top we then attached the panel A grade side towards the frame with 3/4" screws. Now we had cut the fabric so it would basiclly wrap around the board completely minus a couple of inchs. And of course it was cut longer so it wraped around the ends. Anyway, when we attached the board we made sure it was level and centered. Oh and the board being 6inchs wide we left about 3inchs of it hanging off the bottom edge of screen. Now with the fabric pinned nicely between the board and screen frame we pulled it over and back around of the board, and taped it place. We did it that way so no screw is left showing. I know a picture would much better explain all this, but for now words will have to do. With some tucking and cutting, the fabric is completely around the board snug and tight. Now we did pretty much the same thing with the side masking, 6" wide 1/4" thick panels cut to the length we needed. Tapped the fabric to one side of the panel. Screwed it to the screen frame, and made sure again, it was level, then strecthed the material around to the backside. Ok if you have followed me completely so far, we have a screen and a big 6" wide framimg of black on the sides and bottom. Now knowing I wanted a constant surface area screen, the top masking had to be varible. For the top masking at this time, we just have a big section of the black material attached to long wooden rod, propped on top of the frame. Oh, we also sowed in one of the 6" panels again cut to the length we needed, so it would have weight to it, and lay against the screen nicely. To bring the masking in, we have to get up on a chair to manual roll/unroll the fabric. Soon we will have a custom rod system from a drapery company, that all we will have to do to bring down the top masking is pull a rope on the back of the screen frame. "Ok", you say "but how does that give you constant area?", I am getting there! So now that the top panel of masking can be raised and lowered, we need a way to give us varible side masking as well. For this (and note we haven't gotten around to this yet), we are gonna make two 9" wide black fabric panels, and two 4 and 1/2" panels. We are going to attach that to the back of the top masking with velcro.
How the varible masking all works, to give us constant area:
We concentrated on two things for our constant area screen. One was to make sure we could get a constant area for the 3 major aspect ratios (1..33, 1.85 and 2.35), and two was to be able to frame each of those aspect ratios with black masking. In other words, if the certain sections of the screen aren't getting a picture, they are masked off by black material. Ok for TV viewing (aka 1.33 aka 4:3) we will have the top masking up at the top. And we will use those two 9inch wide panels one on each side of the top masking, extending down to the bottom masking. For 1.85 movies, we will use 4 and 1/2" panels, with the top masking brought down a little. For 2.35 movies, we will just bring the top masking down, while the permament side and bottom masking do the rest. And how this works incunjunction with our projector is we use the zoom, to make the 4:3 image small enough to fit between those extra 9inch panels and the top and bottom. Then for 1.85 movies I will use the zoom to make it a little bigger so the full width of the projected image is used, but it will still fit the width with those extra 4 and 1/2" panels. And for 2.35 movies I use the zoom to make it even bigger, and then the top masking is brought down even further then for 1:85 movies. Oh BTW, Its a 4:3 projector, and I am using a PC for DVD playback, and dScaler for TV/satellite viewing. The projector can move a computer image up or down, so I move the image down until it hits the bottom masking for each aspect ratio that is viewed besides 1.33. With 1.33, the iamge is center, because its using the full projector resolution. I have the projector in table top mode, in the back of the room, shooting just over our heads. So what happens when I zoom in or out, the bottom of the projected image doesn't really move, truth be told I think it moves half an inch or so, when I make the projected image bigger. But with the projector being able to position a computer image where ever I want, that is really a non-factor. We went with constant area, becuase we knew if we used a 4:3 screen, the TV viewing would seem EXTRA large, when compared to viewing a 2:35 movie. Also I will make a note here, that we use the maxium width of the projectors image for each and every aspect ratio, its just for movies that we have to "throw away" pixels in the vertical domain, until someone loans me a panamorph on a permanmet basis.
Whew! Any questions?
PS sorry for any bad gramer or spelling mistakes, its late here!!!