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Discussion Starter #1
I am trying to find some material to go around my projector screen and to act as the black bars in 2.35:1 movies. I have a HC4900 that is getting better at showing blacks, but is still a dark grey, but I will be making some adjustments in the future again.


My question is, would the contrast between very black and the lighter black (when the screen goes completely dark) be too big of a difference to look good? Would the picture look worse because it would look washed out and faded since it could never get that black? Or is it a case where you would never notice that the border is really dark?


Would it be better to get a black felt or something else that isn't jet black, or is black velvet the only way to go?
 

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Quote:
Originally Posted by Caps18 /forum/post/13003026


Would it be better to get a black felt or something else that isn't jet black, or is black velvet the only way to go?

I don't have any answers Caps18 but I *do* have a 4900 and:


1. I'm presently using a perfectly white screen with white borders atm. In other words I've zoomed the images to sizes that ASSUME a border material.


2. My border material will be black felt (which is a wool material AFAIK), at least that's the plan right now (I don't have it yet so have no idea what it looks like or how it will perform)


We're watching our movies with the white border presently and get so wrapped-up in the entertainment we don't notice the white/grey border at all ie. it doesn't interfere w/our enjoyment. But folks here swear that proper masking makes a big difference to perception and so I anxiously await the felt and will be able to feed-back on this, maybe will take another couple weeks tho.


BTW another thing to note is my border will be only 2", at least at first, and my screen extends perhaps 20" from the back wall. Ideally a screen would be wall-mounted and have black curtains on all sides, making for a completely black surround. My 2" border might be a waste of $/effort...dunno yet.
 

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Quote:
Originally Posted by Caps18 /forum/post/13003026


I am trying to find some material to go around my projector screen and to act as the black bars in 2.35:1 movies. I have a HC4900 that is getting better at showing blacks, but is still a dark grey, but I will be making some adjustments in the future again.


My question is, would the contrast between very black and the lighter black (when the screen goes completely dark) be too big of a difference to look good? Would the picture look worse because it would look washed out and faded since it could never get that black? Or is it a case where you would never notice that the border is really dark?


Would it be better to get a black felt or something else that isn't jet black, or is black velvet the only way to go?

Jet black velvet is always the best and this is what is used in cinemas and HT projection screens. There are many types, some better than others, but even the cheapest will do fine.
 

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Discussion Starter #4
Black velvet is even darker than the current painted on borders on my screen. But, I will make 5-7 inch borders on the sides (depending on angle), and however wide I need to make them for 2.4:1 movies. I will have it attached to the bottom of my electric screen, so the bottom one will work by raising the screen up if that makes sense. The top one will hide away under this shelf until it needs to drop down.


I'm going to be trying a medium neutral density filter also to see if that will bring everything down (including full black screens in the movie)


I have used black felt in the past for a 1.5" border, but I will try the black velvet this time since some will be lit up (by the black bars from the projector) and some won't be.


Thanks.


(And New Zealand is a great country, I was just there in December. Except for some reason the entry immigration agent didn't think I was going to leave.
)
 

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Quote:
Originally Posted by Caps18 /forum/post/13008306


Black velvet is even darker than the current painted on borders on my screen. But, I will make 5-7 inch borders on the sides (depending on angle), and however wide I need to make them for 2.4:1 movies. I will have it attached to the bottom of my electric screen, so the bottom one will work by raising the screen up if that makes sense. The top one will hide away under this shelf until it needs to drop down.

Can you explain in greater detail what you are actually doing here I dont understand?

Quote:
Originally Posted by Caps18 /forum/post/13008306


I have used black felt in the past for a 1.5" border, but I will try the black velvet this time since some will be lit up (by the black bars from the projector) and some won't be..


If you have a very large area to cover like a cinema screen, black velvet is always used in the areas close to the screen (say 2' wide) and light weight black felt is used beyond that. This is far cheaper than using black velvet all the way to the far extreams. Again this all is only necessary with movable masking. Black felt will never do the good job of blanking white as black velvet will.
 

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Discussion Starter #6
It's hard to explain, but I will eventually get pictures up on this site.
 

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Caps18


You are hitting upon an legitimate issue with masking a screen image. It's well known, and trivial to demonstrate, how the apparent brightness of an image is affected by adjacent contrast.


If you have a dark gray against a jet black you will perceive the dark gray as lighter than if the background were lighter than the dark gray. So it's a real issue if you are talking about scenes that are mostly dark, against the pitch black of your velvet border.


There is also what is known as the "surround effect" in terms of our vision; when an image is surrounded by a darker area our eye purportedly reduces the contrast of the image. That's one reason why the gamma was selected for CRTs because it was generally assumed the TV would be watched in fairly dim light and the boosted gamma boosts the contrast in the mid tones to compensate for the surround effect.


The upside is that apparent contrast, or at least apparent brightness, is increased for brighter areas of the image, because they benefit from being against a contrasting black surround. It's a trade-off.


In general I find, like most people, that an image masked by black has more "pop" and

appears more vivid.


One compensation for the black border effect, in terms of making your projector's dark image look lighter, is a sort of hard to explain benefit. When your image is surrounded by black it takes on a cleaner, more window-like aspect. And the dark areas of the image, which are essentially dark shadows, aren't competing with other gradations of shadowed area. If you'd projected the image on an off-white wall, the wall would be one shadow grade above black, your "black bars" of a 2:35:1 film would be the next shade above black, and your black areas in your image would constitute various other shades. So in a way the dark areas of your image become another shadow on the wall.


But when you remove all competing "wall shadows" and only see the image content, you sort of accept the dark areas as a natural part of the "window into the scene." If that makes any sense.


Some people actually do a bit of bias lighting behind their screen to alleviate their eyestrain and/or make their projector's black areas look darker. But personally I find it distracting and the cleanliness of the image surrounded by black is a more involving trade off.


Hope that helps.


Rich
 
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