[Lord British]

Hi all - from what I've been reading, I gather that a 4'x8' screen needs to be cut down to 48" X 84" to provide true 16x9 aspect ratio? So I guess basically 1 foot needs to be chopped off the length? Would this allow room for a 2" border all around?


Thx!


LB

 

[JDLIVE]

Actually it should be 48"x85" for a 16x9 screen. If you use 2" for a border, then you'd be down to 44"x81" since the border would be 2" on each dimension.

 

[mbaxter]

Actually 4x8 is a good "compromise" aspect ratio if you're going to be running your system off a home theater PC (HTPC). If you don't use an HTPC, disregard this post.


Still reading this? Ok you must be an HTPC user, so let me explain why a 2:1 AR screen is not a bad thing. Virtually all movies are either 2.35 or 1.85 (usually the former). 1.78 aspect ratio, that is to say 16:9, is only used for HDTV, not movies. If your main emphasis is movies, I would advise you to stick with the Parkland in its original 2:1 dimensions.


Use Theatertek for playing DVD's, and set it to automatically resize 1.85 and 2.35 movies to completely fill the 2:1 AR Parkland screen. This will give you a perfectly masked image (the image will be perfectly framed by your black masking borders) on ALL movies. When TT resizes 1.85 movies, you'll lose a tiny portion of the top & bottom. For 2.35 movies, you'll lose a small bit on the sides. Unnoticable in both cases, and definitely worth the perfect masking effect.


Whenever you have a screen with black borders, and the image fills it completely, you get a far superior effect which is easy to observe but hard to explain. I have found that 2.0 is the perfect aspect ratio because for those occasional 1.85 movies, losing a bit on the top & bottom is fine, and for the 2.35 flicks, zooming them in to fill the 2.0 AR screen is much nicer than seeing them on a 1.78 screen with gray letterboxing on the top & bottom. There's never anything to see at the extreme left & right edges of those 2.35 movies anyway.


But like I said above, none of this applies unless you use an HTPC. If you use a set-top DVD player you need to stick with a 1.78 AR screen because set-top boxes don't have the zoom/resize capabilities of a PC.

 

[HorrorScope]

I agree with mbaxter. To really polish off a projector and it's effect you always want to go for a full screen. Anything less looks like the project isn't finished. It becomes a 100" plasma.

 

[b2bonez]

Odd that you should come up with the 2:1 ratio that most theaters use

that were built from the mid '80s on. The OAR evangelists would

condemn your compromise as heresy, but sometimes by giving up a

little you can gain a lot in other ways.


b2b

 

[Rob4x20]

interesting, mbaxter.


I have a 7x9' piece I was going to cut into a 60.75"x108" for 1.7777 ratio. But you think it's better to do 54x108"?


Just to be clear, that means the 2.35s would zoom in and cut off some of the sides? While the 1.85 would zoom out and cut some of the top off? How many inches? I'm confused....


Also, what happens to HDTV? I have a set top box for this as you mentioned. Could I not just zoom and have unused screen areas? They'd be on the sides, right?


btw, I do use htpc and will buy theatertek if need be!


Thanks,


Rob

 

[Lord British]

Thanks for the replies everyone - to tell you the truth, I'd rather not cut my screen if I don't have to.


mbaxter - I don't have an HTPC right now but I was planning on building one in the very near future... I am a bit confused by your post though...


so I don't cut the screen and still put the 2 inch black border all around.. so wouldn't my screen now have a 44" x 92" viewing area which is no longer 2:1?


and then I have to use a program like TheaterTek to fill the screen.. does this distort the image at all or just zoom it which causes it to lose a little picture as you stated?


and like Rob4x20 asked, what happens with 1.78 HDTV that is left untouched?


Thanks!


LB

 

[mbaxter]

Quote:

Originally posted by b2bonez Odd that you should come up with the 2:1 ratio that most theaters use that were built from the mid '80s on. The OAR evangelists would condemn your compromise as heresy, but sometimes by giving up a little you can gain a lot in other ways.

Interesting I didn't know that movie theaters use 2:1...hmmm


Quote:

Originally posted by Rob4x20 I have a 7x9' piece I was going to cut into a 60.75"x108" for 1.7777 ratio. But you think it's better to do 54x108"?

Yes I think so, because I find 2:1 to be the best screen AR for movies. Keep in mind I use my HT for two things: watching standard definition TV and DVD's. If I had HDTV, a 2:1 screen would probably not be the best choice.

Quote:

Just to be clear, that means the 2.35s would zoom in and cut off some of the sides? While the 1.85 would zoom out and cut some of the top off? How many inches? I'm confused....

You're not confused, you're correct.


How many inches cut off depends on the size of your screen. If you had a 54x104" screen, and you zoomed a 1.85 movie so that it completely filled the screen (this would be a 56x104" image), you'd lose one inch off the top and bottom. That's 2% off the top and 2% off the bottom. Will you notice that? I never have.


On 2.35 movies, after zooming it to fill the 54x108 screen, you're losing 9.5" on the left and right. I don't mind this at all, because there's never anything much going on in those extreme far edges. You don't miss them, and the perfect edge-to-edge masking can't be beat.

Quote:

Also, what happens to HDTV? I have a set top box for this as you mentioned. Could I not just zoom and have unused screen areas? They'd be on the sides, right?

If you have HDTV, you may want to think twice about going with a 2:1 screen. HDTV is 1.78:1 and if you're viewing it through a set-top box and not an HTPC, then you're going to have to zoom/unzoom every time you switch between watching DVD's and HDTV. Not worth the hassle in that case.

Quote:

Originally posted by Lord British Thanks for the replies everyone - to tell you the truth, I'd rather not cut my screen if I don't have to. mbaxter - I don't have an HTPC right now but I was planning on building one in the very near future... I am a bit confused by your post though... so I don't cut the screen and still put the 2 inch black border all around.. so wouldn't my screen now have a 44" x 92" viewing area which is no longer 2:1? and then I have to use a program like TheaterTek to fill the screen.. does this distort the image at all or just zoom it which causes it to lose a little picture as you stated? and like Rob4x20 asked, what happens with 1.78 HDTV that is left untouched?

I wouldn't want to cut a Parkland either. Those things are a major PITA to cut manually.


To get exact 2:1 AR I would just use 2" masking on the sides and 1" top & bottom, giving you a 46x92" screen.


The nice thing about playing DVD's through a computer is that you have such outstanding scaling capability. Good software players like TheaterTek and Zoomplayer can do this without any quality loss.


BTW, I should have made something clear in my first post. To use a 2:1 AR screen, you need to have everything run through the computer, and the computer should have PowerStrip installed so that it can output a true 2:1 resolution. For example, my system runs at 1024x512. TV, VCR, DVD, Windows, everything goes through the PC and enters the projector via the same VGA cable. Thanks to the HTPC, all types of output are confined to the 2:1 area defined by PowerStrip's 1024x512 custom resolution.


This is why I don't mind a 2:1 screen. If I was using any set-top boxes, the 2:1 screen wouldn't work.

 

[mquinn25]

Interesting...I saw this actually a few minutes ago on carada.com that they offered a 2.05:1 aspect ratio screen...and now mbaxter brings it up here.


I could probably live with the top/bottom loss on the 1.85:1........but it seems like you'd lose too much on 2:35:1......19 inches of picture on a 108" screen?....is that correct? That's almost 1/5 th of the picture.


I'd rather mask if those figures are correct. I'll do the math when I get home.


MQ25

 

[Lord British]

After thinking about it a little, I think I will go with a true 1.78 screen because I will be viewing a lot of HD among others things not on the HTPC. So, given that I will have a 4'x8' piece of screen to work with, these are the calculations I've come up with - someone PLEASE correct me if I am wring anywhere:


4'x8' = 48" x 96 inches....


since I will be putting a 2" border all around, the viewable height will be 44" (2" off the top and 2" off the bottom)


44x1.78=78.32


I should have the screen cut to 82.32 in width, so that after I add the boarder I will end up with a 44" x 78.32" viewable area.


LB

 

[gambit]

To be anal about it, 16:9 = 1.77777777777777... : 1. So the width is 78.222222222222222....


Also, make sure to check the actual dimensions of the board that you are working with. 4' x 8' is not the true dimensions. For example, the Do-able board that I used comes in 4 x 8, but when you actually measure the width, it is more like 49" instead of 48". I forgot what the overall length was. So if you truly want to get a 44" height with 2" borders, you'll need to cut some off in that dimension as well. Or you could just go for maximum height and recalculate the width accordingly.

 

[HorrorScope]

Personally I would go 16:9 and smart stretch 4:3 and zoom 1.35 to 16:9 if I wanted a full 16:9 filled each every-time.

 

[lespurgeon]

Rob-

I would make the widest 2.35:1 screen I could with your parkland and use drapes to mask the side to as small as 3:4. Of course this would require adjusting zoom on the projector, but if you have the room for it, cinemascope would look real nice.