[sbm911]

I'm readjusting my projector's position to be closer to the screen than my previous set up based on new room size, and need to reduce the size of the screen surface from 96x72 to 86.5x65.


Currently using a Da-lite B manual roll up which I want to keep for a while longer and potentially use again at full size.


Is there a way to mask the sides from 96 to 86.5 so that I can still roll into the casing, but not do permanent damage to the screen in the now masked area?


-Steve

 

[Durwood]

Steve, it depends on how handy you are. I think the most economical way would be to visit a materials store like Joanne's Fabric, ( if you have one of those in yoru area), or any materials shop. The material you will need is about a little less than a 1/4 of an inch in thickness. It is black on one side ( excellent ligh absorbing material, and grey on the opposite. It's usually used as headliner material in automobiles. It comes in about 5 foot widths, maybe less, and can be cut to fit your application. To mask the sides and top, you'll need to of course measure. Then take your measurements and begin cutting the fabric. I used some metal aluminum for a straight edge to cut the length of mine ( mine are used as masking devices for 2.35:1 movies), the same application will work for not only a top and bottom, but sides as well. You want to get the edges as straight as possible, this can be achieved if you use a long enough piece of aluminum ( you can find this at Home Depot, or Lowes') Next, while your at HD or Lowe's, head over to the borders area, look for aluminum boarders in lengths of 8 feet, this will be perfect for what you need, they are light and very sturdy, so as not to sag or bend. These borders are straight and perfect for using as a masking. They have a "U" shaped bend around the top that can be used to fit the foam material in very nicely. Use a hot glue gun to adhere the foam to the aluminum siding once you figure your length. Make sure the black material is facing you, not the grey, because it's the black that you'll want for light absorption once the borders are made. Next, head over to the "fasteners" section of HD or Lowe's and pick up some round magnets for fastening to the masking panels you've now created. I would use around 3 per panel, perhaps two for your sides. Depending on the dimensions, you can put up the panels so that they are flush. Now, the right angles are created on each corner of the actual screen. At this point, your probably wondering how these will stay in place once you let go. Take the extra magnets, and with a friend, have him/her attatch the magnets on the back side of the screen surface, this works quite nicely, and you'll even be able to tweak it out for a perfect masking all the way around, even with slightly different program material. I'd put on a few discs that you feel comfortable with, and begin your measurements you'd like before hand. You can even create some 4:3 panels for Video material or satellite stuff if you want. The panels will stay in place as long as you don't disturb the screen during viewing. The magnets also will not marr or damage the front screen material, ( this to me is the most important, especially since you mentioned that in the future, yo'd like to use this screen again without the masks.) I painted the front of the aluminum masking panels flat black, your edges will have a crisp, clean look with no jaggies that would be evident had you cut the foam material with scissors. Because certain movies are framed differently on each DVD, this is a perfect remedy for creating in addition an illusion of better black levels ( if you are an LCD or DLP guy) In the end, this looks very clean and professional. If you have to start over, don't worry, it takes some practice. The first time I used aluminum railings used for screens. I couldn't find custom cut lenghts, so had to do it myself, I could never get a straight enough edge until I found the aluminum boarders.........very frustrating, they had a tendency to bow. All toll, you might spend $40.00 on this gettup, works like a charm!!! Good luck

 

[smyth22]

Very useful idea. I have one question; what are the borders normally used for? My HD did not understand what I meant by borders. Are they used for siding or ? Thanks for your help.


Peter

 

[Durwood]

Peter, I believe the "borders" reference was a poor one. The item is normally referred as wall trim............I believe that's what it is called. If you can't find it at HD, I am planning on going there tomorrow anyway, I can find the item number and get back to you on that. When you find it, they will be positioned horizontally, you'll see brass ones also. They are about 1 inch in height, and of course 8 feet long, perfect for a 92 inch widescreen matte. Once you find it, you'll see exactly what I'm talking about, it's easy to fit the foam into the siv of th trim, forming a very neat fit and clean edge, once painted flat black, it will match the color used in the black foam when looked at. Let me know!!!

 

[sbm911]

Thanks for the useful detailed post.


I guess I'm not visualizing correctly.


Is the aluminum border on the "inside" of the mask?(i.e., on the bottom of the top mask)


Where are the magnets placed? On the material supporting the hanging border if the above assumption is correct?


How are the sides supported (remember I'm trying to shrink the width also by 4.5 inches a side)? Will magnets on fabric be enough to support the vertical hang of the aluminum without sagging?


Or am I interpreting wrong?

 

[Durwood]

I am going to HD today, I will get back with you and show you which aluminum wall trim I'm referring to, once you see that piece, it will be more clear. I'll go ahead and try to explain in more detail. I'll refer to the wall trim piece as "border". When using the border the actual masking edge goes on the inside of the screen, not the outside, because we want the straight edge to be within the screen, not on the outside. The same would apply for a top and bottom. The top piece would have the boarder edge where the black bars begin, as if you were looking at the movie from the middle and then visually scanning to the borders of the movie, i.e. looking up and down, and both side to side. The aluminum border edge to the panel goes on the inside as opposed to the outside because if you use the foam as the interior masking border, you will have a difficult time creating a straight edge, and if you even have semi good blacks using your projector, they will never be black enough compared to the border. Using the metal edge as the true border ( painted black as opposed to leaving unpainted, aluminum) helps just with the lines that differentiate between the moviing video, and where the black bars begin ( both for top and bottom, and for left and right). Imagine standing back and looking at your 16:9 image, you have the black bars on the top and bottom. You take your panel you've constructed, velvet black material out to mate the black bars, grey material facing screen. The one inch flat backside of the aluminum border ( unpainted ) is what will be facing the screen. You've already attached small round magnets to this side of the panel to attach to the screen. The magnets "mate" will be on the opposite side of the screen, creating a "sandwich" looking at it from the side from left to right would look like this:


1/2 inch of panel (painted black) - foam material black side facing left, grey facing right .........hotglued to - 1 inch of panel not painted because this is where the foam edge fits into the siv of the aluminum border - the magnet that you have hot glued to unpainted backside of 1 inch aluminum border - screen - magnet to hold panel in place, and to adjust as necessary.


The 1/2 inch and 1 inch designators when viewing from the side are like this. Imagine looking at the panel from a cross section, the aluminum would form what would appear to be a "hangman game diagram", this is where the foam is is inserted and hot glued to the aluminum. Once you see the border trim at HD, you'll see what I mean.


To answer your questions if I can.


The magnets are not placed on the material, they can't physically, or they will fall off after about a day. The foam material isn't rugged enough, and the foam is too poreous, the hot glue wouldn't adhere to the material. The hot glue adheres to the aluminum just fine though, you'll need three across each panel because the middle will like you said, sag a little, not because of the aluminum mind you, but when the screen pulls up taut against the magnet on the left and right, the middle needs the slight adjustment also, this is where the middle magnet is important. The middle magnet is needed to be adjust and bring the panel border straight with the video black bars from left to right, or in your instance, top to bottom.. measure the 4 or 5 inches of material and visualize what you actually need to mask, once you cut the material, your kind of stuck with the dimensions, so make it count.


The sides are supported in the same manner as the top and bottom. Except for the top, I had a manual roll up too, and for the to portion, on 2.35:1 movies, the black panel will be free standing. The bottom portion of the top panel will be fine because of the magnets used, but the top portion won't sag, but it will be tall enough that if moved off of the screen, can fall. I used paper clips the "black v shaped" ones, you can find at Office Depot or Staples. You can clamp down the material to the screen at the very top next to the casing. You will not see them during viewing when dark. I don't think you'll need them for your application, but it won't hurt to pick up some "V clips" just in case. My 4:3 panels I used didn't require them. I had a DaLite Model C 16:9 106 inch diagonal.

 

[smyth22]

Thanks Durwood: I think I know what you mean by wall trim and I will check out HD over the weekend. Of course if you have a part no. so much the better. An alternative I'm considering is plain out roller blinds (if they have a nice matte black option) attached at the top and bottom of the screen. I would attach a series of brackets outside the edge of the screen to fix the blind at the heights needed for the various aspect rations. I am thinking I might insert a wooden dowel in the leading edge of the blind to ensure a straignt edge and extend that dowel outside the edges of the blind to allow the blinds to be secured by the brackets. Anyway HD should be able to handle both possibilities so cost and ease of installation will probably be my criteria.

 

[hardvark]

Durwood,i'm interested also in the border idea.sound's like a neat way to vary a screen's aspect ratio.could you list part# or maybe a pic to help us understand exactly what we are looking for? thanks