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Discussion Starter #1
Hello fellow shacksters!

This post may come across as blasphemous to projection common sense, but... does anyone have any links to resources about how exactly black borders enhance image quality on projection screens? And under what circumstances? In my own personal situation, I'm not yet convinced. I've read about there being a perceived brightness boost, and I've also read about a perceived contrast boost. The brightness boost I think I see, but I'm not sure about the contrast part. Now, this may not be the border's fault. I just don't know yet. Let me explain my situation.

I recently went from projecting on an off-white wall to projecting to a white blackout cloth. That could be the culprit right there. But, I now also have a 3.5" black velvet border around the BOC screen. I would think that this border would make up for the perceived loss of contrast from going from off-white to white (not really a vast difference in the whites).. but this border doesn't seem to be helping, and I kinda think I took a minor hit in overall image performance.

Might it be possible, that if your projector's blacks are lighter than a certain amount, a velvet black border might actually hurt contrast by "reminding" you of what black is supposed to look like? I sometimes wonder this while watching movies. It just seems like the velvet is sooo much blacker than any projected black on the screen now. It's as if it's creating a new contrast where there was none before. Before, the only black reference I had was the black that the projector could create. Now, to my mind anyway, it seems that there is now a new standard of black that is constantly demonstrating its superiority by highlighting the difference between itself and my projector's blacks. lol I'm wondering if the "perceived brightness boost" is actually brightening my blacks as well?

To my mind, the bias lighting thing seems to make more sense to me (if not overdone). As far as black border and contrast ratio goes, I'm not yet convinced (just from my own experience).

Now, to be thorough, there could be other factors affecting me and it may not be the black border. The blackout cloth may be presenting a softer or duller image in some way. It may not be a good blackout cloth for my application. Also, it may be the case that going from the off-white to the BOC white actually is such a drastic change that the black border can't compensate for it.

What are you guys' thoughts on this? Do you think there is possibly a situation where black border should be minimized (made thinner)? Or should a projector be able to create blacks to a certain depth before a black border really brings out the contrast? Am I just weird? Don't answer that.


Thanks!
-Jon

P.S. With my new gray screen, I'm going borderless first, just to experiment.
 

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I have a 16:9 screen. When I play 1.78:1 movies, the image is entirely framed by the 3" wide black-felted border of the screen's frame. With higher-ratio OARs, the image is framed, top and bottom, by the 1.0-gain white screen itself. I can't say that I've ever noticed a decrease in contrast resulting from "missing" black borders top and bottom.

IMO, adding borders may work for some (many? most?) folks, but I don't think they're essential. YMMV, of course. :)
 

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Discussion Starter #3
Hey Eljay! (Gotta say, your home theater looks fantastic!)


Thanks for the response! Yeah, I think it may definitely be an individualistic thing. A couple weeks ago, I watched Dark City on the bare wall and I thought "This contrast doesn't look so bad." Then, I watched it on my Samsung d630 lcd TV, and I thought "Hey, the contrast on this TV isn't significantly better than what my HC4000 produces. Nice! But then later, when I had my projector pointed at my black out cloth screen again, I remember thinking "eek" when I watched Gray City. I mean Dark City. :rofl: :R

It may just be the difference in whites between my off-white-ish wall and the white black out cloth. Or maybe the difference between the hard wall paint and the soft cloth. Who knows. One thing I have noticed is that my screen feels smaller to me since I put it in a border. That's definitely true in my personal experience. I think that has to do with the width of the border maybe. I'm kinda thinking in terms of TV. In my experience, the smaller the frame on the TV, the bigger the screen looks. To me, anyway.

I've seen it mentioned in many places that black border enhances perceived contrast ratio, but someday I'd like to see the original experiments or studies or whatnot, and see their conclusions and see if there were any notable exceptions (purely out of my own geeky interest). lol Can't help but think "maybe I'm doing it wrong."
:dontknow:

The fact that I watch a lot of darker movies may make a difference as well.
 

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j0nnyfive said:
Hey Eljay! (Gotta say, your home theater looks fantastic!)
Thanks! :)

I've seen it mentioned in many places that black border enhances perceived contrast ratio ... Can't help but think "maybe I'm doing it wrong."
:dontknow:
This isn't intended as a dismissive comment, but if you're not seeing what other people are (or claim to be) seeing, why worry about it? IMO, just sit back and enjoy! :cool: :D (In case you can't tell, my rule of thumb is: "If it ain't broke, don't fix it.")

The fact that I watch a lot of darker movies may make a difference as well.
Just don't let it affect your sense of humour. :bigsmile:
 

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Discussion Starter #5
Howdy!


To answer your question of why worry about it (because it is a fair question that I forgot to address), I'm making a new screen. This new screen won't have a border separate from the substrate. I'm going for a "less is more" approach. The dimension may be affected by my border thoughts, but maybe not. I'm going to allow for a 3 inch border because I'm too chicken to not allow for a border. So, I wanted to do some border research. lol It's not really a big deal, but it's one of those things that you hear a lot. Once you've heard something enough times, you begin to wonder where it came from. :ponder: Or at least I do. I think a lot. It's what I do. That's why I'm here! Yay! :clap: lol

I like this site. People here get surious yo.

Dark movies have probably formed my sense of humor. Is that bad? lol

I guess another reason I'm wondering about this is that I'm not sure if the border actually has anything to do with my perceived loss of contrast or overall image quality. And, I'm not really sure exactly what's causing it if it isn't the border. Puzzling. :huh: But it's just sort of a science thing I'm interested in, not really after "advice" per se. Anyway, that's kind of my personality for ya! :) Curious George.

"If It Ain't Broke Don't Fix It" <------ Good advice.
 

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Discussion Starter #6
I found an interesting link that hints at some technical science stuff about it!

http://www.avforums.com/forums/projectors/1340774-science-behind-black-border.html


I like the picture demonstration! If you look at the gray square inside the black box... all I can say is... yes! That's what I see too! Not saying black isn't the best way to go, but I wonder at all the little interesting tricks my eyes are playing on me, and how to take advantage of that to optimize my theater for dark movies. Love 'em black levels. Woohoo! I'm wondering about having just a thin enough black border to frame the picture, but then having a little bias lighting and cast a level 8 illusion spell.... oh er.. I mean, well... ahem.
 

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The concept of a black boarder increasing perceived image contrast (and perhaps brightness) is based in fact, BUT there are so many other factors that enter the equation that simply saying a black border alone causes this effect is a bit of a misnomer.

I had a link that explained this, but it was one of the few that weren't backed up before my last PC died; and while the data is theoretically retrievable I haven't had the time to do it. Note: NEVER use a hard drive controller card that uses proprietary drive formatting!

Screen borders are also very subjective, some like them and some don't; so it eventually falls to user preference. As far as I can tell the biggest reason to add a black boarder is to absorb any image over-spill and to provide a "picture frame" look in regular room light.
 

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Discussion Starter #8
PC death. Not an easy thing to live with. Life moves on, but there will always be a part of you that is lost forever. The PC lives on in memory... what? Sorry.

Harp, that's interesting that a document like what you are referring to exists! I'd love to read it! The fact that there is more to it than the binary choice "black border vs no black border" is something that I began to suspect after my own experience with Dark City. There seems to be something else to it. I would love to learn more about this particular topic so I can maximize my contrast, particularly for movies like Dark City, The Dark Knight, The Crow, Friday the 13th (original), Terminator, etc. Right now I'm leaning toward not putting a border on my new screen. I think my geometry is good enough not to need it. Now I'm curious about bias lighting and whether it could help.

I got so caught up in what to use for a black border in the other thread that I didn't stop to think about my reservations about even having a border. lol :dumbcrazy: With the 3" extra area on my screen (which I haven't picked up yet), I'll always have the option of throwing up a black border later.

I'll try to find some links for anybody who may be curious about this subject.
 

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I have a white screen (1.3 gain) on a complete black wall. Black curtains on either side. And to top it of a black ceiling. In my opinion this contributes to very little light reflection and that you get drawn into the movie with no effort. On the DVE HD Basics BD is a test that shows that colors seem to change when the background is slowly changed from white to black and vice versa.
 

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Maybe I'm missing something but isn't the whole idea that the border (being made from a dark non-reflective material) allow you to have a "perfect" projected image by "absorbing" the overscan portion of the projected image?
 

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Maybe I'm missing something but isn't the whole idea that the border (being made from a dark non-reflective material) allow you to have a "perfect" projected image by "absorbing" the overscan portion of the projected image?
That is the main reason in my opinion.
 

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Discussion Starter #12
Puulima,


You're not missing anything at all! That's a great reason to have it! I didn't mean to sound like it was a bad idea. I guess the reason I started this thread was really to see if there was something I was doing wrong in terms of contrast. The reason I had a border was because I had a blackout cloth screen. The border was simply there to hold the cloth on. The instructions I found on how to build that screen were intended for an acoustically transparent screen. I didn't know anything about screens at the time so I just built a regular cloth screen without the AT material (didn't want to buy expensive material). And I was of the mindset that a good screen had to be made of cloth.

Now that I have found this wonderful (did I mention wonderful?) forum on DIY screens, I have all these great options with science (instead of hand waving) to back it up! I have started planning for a new screen, and I was rationalizing that the reason to have a black border was to help with contrast. So I have been experimenting with the border. To have it? Or not to have it? I wanted to keep it for helping with contrast, if it could do that.

Now, that part of it just didn't work for me. So why don't I just keep it anyway? Because I like having the freedom to change my screen size on a whim without people suspecting that it's supposed to be a certain size. Not having a border makes that easier for me. (btw, I'm painting the wall now). I may devise some kind of masking system later that doesn't rely on a predefined border. Don't ask me how. lol Another reason why I personally don't like my border is because, to me, it made my screen seem smaller. Why? I have no idea. I had a friend come over and he said he preferred the border. So, I'm an odd duck. But, since I'm the one that has to live with it, it's going away. :)
And, I just didn't like the look of it from a "it cramps my style" perspective. I'm pretty minimalist.

Sorry for any confusion! If in doubt about whether you should have a border (for any newbie reading this who may be having second thoughts because of my back and forthing), I would think that it is indeed to handle overscan. I'm now convinced that that is the main reason. And also, if you are normal, you will probably prefer the look of it as did my friend! Thanks for reading!


P.S. I just thought of this! Another reason the border annoyed me is that I'm using an HC4000 DLP projector so I don't have lens shift! I can't easily move my image up and down the wall to fit it in the frame just right. I had to use little strips of paper towel to wedge the projector just right! Can't believe I forgot about that! lol Lens shift is important. My next projector will definitely have it! Sorry for leaving that out! So many factors to consider...
 

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Discussion Starter #13
HTip,

That setup sounds very ideal! Unfortunately for me, it may be some time before I can approach anything close to that (due to money, apartment life, etc). That's why I'm loving the idea of gray screens! It's almost as if you can just stuff all that "ideal-ness" into the screen itself! lol
 

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HTip,

That setup sounds very ideal! Unfortunately for me, it may be some time before I can approach anything close to that (due to money, apartment life, etc). That's why I'm loving the idea of gray screens! It's almost as if you can just stuff all that "ideal-ness" into the screen itself! lol
Thanks! I feel very fortunate to have been able to realize this setup. It was a long lived dream...

Grey screens (negative gain) generate a higher contrast, so that is a way to create a better picture. You need a higher light output from your projector though.

By the way, have you heard of the Black Diamond screen from Screen Innovations? It is not cheap but theoretically you can shine light directly onto the screen and still have a good picture.
 

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Grey screens (negative gain) generate a higher contrast, so that is a way to create a better picture. You need a higher light output from your projector though.
Interesting - I just posted a long winded intro and "seeking advice" post on my room/lighting/projector/thow distance etc specs trying to determine if a white or grey screen is the way to go. Definitely want to max on contrast and color richness - but since this is my first projector and home theater setup - I have NO IDEA if my projector is bright enough/too bright etc etc.

It's an Epson 8350 - decent first projector and was on sale. If you can advise on the specifics relevant to your comment above - that would be great.
 

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...I just didn't like the look of it from a "it cramps my style" perspective. I'm pretty minimalist
Actually - That's why I was seeking clarification. I've never thought of the border as a way to impact contrast at all, figured in a dark room, it disappears anyways so moot point right? But I'm of the minimalistic way of thinking also - the BEST looking screens I've seen in all the posted picture are the ones that remind me of the old Drive In Screens (if you old enough to have been to a Drive in!
)

The "overscan/overprojection" just went off into the sky and the floating white screen looked perfect as is. I don't have the forum posting handy (it's buried in one of dozens of new "Favorites" in Firefox) but I have a few of great looking screens with no border. I believe they were not DIY screens though?

Sorry for any confusion!
No confusion - just trying to wrestle with this also. With the Laminate I'm going to go with (most likely) - and the complete glue down approach - like a countertop - so one rigid screen - I think I can get away with no border. And I was planning to set the screen out from the wall a ways - 2" gap behind at least - maybe more? But I'm thinking I will need to paint that wall black or a (very?) dark very flat/matte color to absorb the overprojected light - and still that may not work so may need a black light absorbent material?

And that's where the wife will jump in with a horrified look on her face....

Let me know what direction you go in...would love to hear additional thoughts.
 

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Interesting - I just posted a long winded intro and "seeking advice" post on my room/lighting/projector/thow distance etc specs trying to determine if a white or grey screen is the way to go. Definitely want to max on contrast and color richness - but since this is my first projector and home theater setup - I have NO IDEA if my projector is bright enough/too bright etc etc.

It's an Epson 8350 - decent first projector and was on sale. If you can advise on the specifics relevant to your comment above - that would be great.
It all depends on screen size and throw distance. For instance if you have a 100" screen and your throw distance is anywhere between 11 and 18 feet, a gray screen (0.8 gain) will do fine with your Epson.

You can fiddle around with the parameters on this calculator. Keep in mind that you want to be somewhere in the middle of the zoom range, not at the far ends of either wide or tele.
http://www.projectorcentral.com/Epson-PowerLite_Home_Cinema_8350-projection-calculator-pro.htm
 

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I have played around with that calculator...not sure I fully understand what I s/b doing with it...yet ;-)

I might have to paint the wall behind the screen area white and see what that looks like.
 

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I have played around with that calculator...not sure I fully understand what I s/b doing with it...yet ;-)

I might have to paint the wall behind the screen area white and see what that looks like.
I highly suggest doing this - it allows you to get a real good feeling for how big to go for a screen size. You can also decide if you prefer 16:9 or 2.35:1.

As far as the calculator, there is another calculator someone linked a while back that is a bit more in depth - I am pretty sure it allows you change the lamp settings. The thing to remember when using the calculator - watch the number of FL. You really want to be in the 12-16 FL range (I stayed toward 16 to allow for lamp degradation).

Here is a link to that calculator if you wish to give it a look.

Hope this helps!
 

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Discussion Starter #20 (Edited)
Thanks for that tip HTip! lol I did not type that on purpose, but I'm leaving it. Yeah, Black Diamond looks interesting, but I'm tight on money at the moment.


Puulima,

That sounds like a good plan you have going there. I wonder how much "black" it takes to handle overscan to a satisfying degree.


Yeah, I really like the look of the borderless screen. A lot. That drive in theater look you mentioned sounds perfect. Ideally, I would love to have very dark walls with a black screen wall with a white/gray screen just floating there. Love that look. I don't want to paint the apartment though.

Here's where I'm going: My walls are all off white, and the ceiling is white popcorn. The room is small. Single bedroom apartment. Horrible, horrible for home theater. BUT... I'm planning on painting a screen onto the wall. I'm not sure how I want to do this yet though. I want to paint it large enough and non-screen shaped enough that you can't tell "where" the screen will be on the wall, or how large. I love the affect of the screen just appearing on the wall, seemingly out of nowhere. You don't know how big the screen will be until it appears. It throws people for a loop, especially if they aren't used to home theater projectors. In this small apartment, the 115" screen takes up most of the wall and just swallows you whole. I love that affect.

So I'm thinking of painting a very large area on that one wall, and perhaps the entire wall. The problem is that it is the wall the front door is on (over to the right). I'm not sure if this would look too weird or not. I may just paint a very large rectangle that takes up most of the wall. Just trying to figure out a stylish way to do it.

The other reason I like being able to change my screen size on the fly is that it's an easy way to get either some more brightness (smaller) or perceived contrast (larger). Kind of a cheat, but I like it! :D I was a little disappointed with my black levels the other day while watching Iron Man 2. Well, I forgot that my screen size was 110" and I could zoom it out to 115". So, I removed the border we had hanging on the wall (that limited the size to 110"), and I zoomed out to 115" and presto. Black levels instantly better. Love it.

The guys came over one day to play some video games on the projector. The screen was just too big for them so we shrank it down to about 70" or so. Much easier to play that particular shooter game. So, yeah. I'm hooked on having that flexibility now. Again, my projector doesn't have lens shift so that's a big part of it too. But, I like the look! Drive in apartment theater. Nice. :)
 
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