I was watching Transporter 3 yesterday(Blu-ray) and noticed that the screen was invisable,which made me wonder about all of the factors that contribute to that effect. The screen,the room,The projector and of course the source.How many of us can not see the screen? My setup Pioneer RS-2 type,Carada BW,black out room and Blu-ray. JB

I was watching Transporter 3 yesterday(Blu-ray) and noticed that the screen was invisable,which made me wonder about all of the factors that contribute to that effect. The screen,the room,The projector and of course the source.How many of us can not see the screen? My setup Pioneer RS-2 type,Carada BW,black out room and Blu-ray. JB

I can't see my SMX.

I was watching Transporter 3 yesterday(Blu-ray) and noticed that the screen was invisable,which made me wonder about all of the factors that contribute to that effect. The screen,the room,The projector and of course the source.

I think one thing that can make screen surfaces more visible is how bright your projector is. How many foot lamberts are you currently getting off your screen?

I find my screen surface to me more visible above 20 foot lamberts with some material than it is below 16 foot lamberts.

I think one thing that can make screen surfaces more visible is how bright your projector is. How many foot lamberts are you currently getting off your screen?

I find my screen surface to me more visible above 20 foot lamberts with some material than it is below 16 foot lamberts.

How do you people on this section of the forum keep from going blind? Mine is less than 8 foot lamberts and is plenty bright. I couldn't imagine 16 foot lamberts in a room able to be pitch black, let alone over 20. The glare when looking at white credits must be terrible, no matter what screen you have!

8 foot lamberts would be like watching thru cataracts for me - I like it bright!! And I'm using a Firehawk G3 ( 118" wide 2.35:1 ) and a Da-lite High Contrast Cinema Vision ( 106" wide 16:9 ). 12 FL would be a recommended minimum anyway.

I see on average around two sparklies on my 106" High Power (2.8 gain) per 4 movies from 7 1/2 feet away. This is without sitting to avoid them which I have found is possible even at around 20ftl or more. It's just the part remembering to sit very still that doesn't work.

How do you people on this section of the forum keep from going blind?

They wear their sunglasses at night... :D

-Suntan

With my old Sony LCD projector I started to feel the image was too dim around 8 ft-L. After a half hour in the room the image looked pretty good but when I first walked in or I came back from getting a drink it was too dim for a while until my eyes got used to it.

With My RS1 I start out at around 17 ft-L with a new bulb and that is pretty bright for me. Very bright scenes I can feel my eyes straining a little and can feel it during dark to bright transitions. I wouldn't want my setup any brighter. For most of the first 1000 hours on my bulb I am at 12 ft-L or higher which is perfect for me.

How do you people on this section of the forum keep from going blind? Mine is less than 8 foot lamberts and is plenty bright. I couldn't imagine 16 foot lamberts in a room able to be pitch black, let alone over 20. The glare when looking at white credits must be terrible, no matter what screen you have!

Check out the old brightness survey thread.
http://www.avsforum.com/avs-vb/showthread.php?t=984992

I am with you, less than 8ft lamberts looks plenty bright to me. If I calculated the ftL off the projector manufactures figures, rather than measured it I would end up with silly numbers, but I expect many quoting high numbers have actually measured their setups. Afterall crt is what 35+ftL and a two fold increase in brightness would only be percieved as less than a 20% increase.

Viewing distance just over 8ft from a 8ft width screen.
I use a painted (dulux light and space absolute white rich matt with lumitec technology) wall, the screen is not visible expect in all white images, and then only due to my poor diy painting and if I look for it. I tried neutral grey and a silver-grey paint mix both made the screen more visible, in bright scenes with expanses of the same color like clear blue sky. I think image contrast/gamma and color saturation has an effect, the more depth in the image the less likely you notice it the screen.

I can't see my SMX.

Last night I spent 20 minutes looking for my Dalite HP screen, then the wife pointed out that it was hanging on the wall where it always is.

This was one of the improvements I noticed when going from a Greywolf II screen to my current Beamax Matt White tensioned screen. I can't 'see' the screen surface at all even on bright scenes with panning, where my old screen was like watching through a mesh. It helps that I'm sat about 13' back, but I need to as it's nearly 10' wide 2.35:1 format. :cool:

I don't know what my fL actually measures as I tried using an I1-LT to calibrate my HD350/Lumagen HDQ combo but I wasn't convinced it was very accurate (or repeatable). IIRC it was measuring 8-9fL off the screen for 100 IRE, but I've since opened the iris up a little (in the service menu) but also the lamp has more hours on it. All I know is that on bright scenes I can 'feel' my eyes react (probably more down to eyestrain from too much PC work beforehand ;)) and I wouldn't want it any brighter in my fully blacked out room.

Right now I'm just projecting a Panasonic AE900 (720p) projector on to a wall covered in white primer. It looks great. I actually pulled out my sample of Stewart ST-130 G3 material and from what I could tell the gain was almost identical between the wall and the "real" screen material. Not only that, looking up close, the pixel definition was, if anything, crisper on the wall than on the screen material.

Nor can I notice much, if any, texture to the image on the wall either.

Is it possible the difference between projecting on a wall vs using a screen can be over-rated? (That is, unless you need a surface with more directional characteristics).

Last night I spent 20 minutes looking for my Dalite HP screen, then the wife pointed out that it was hanging on the wall where it always is.

I knew I was setting myself up for that.

Right now I'm just projecting a Panasonic AE900 (720p) projector on to a wall covered in white primer. It looks great. I actually pulled out my sample of Stewart ST-130 G3 material and from what I could tell the gain was almost identical between the wall and the "real" screen material. Not only that, looking up close, the pixel definition was, if anything, crisper on the wall than on the screen material.

Nor can I notice much, if any, texture to the image on the wall either.

Is it possible the difference between projecting on a wall vs using a screen can be over-rated? (That is, unless you need a surface with more directional characteristics).

I found the same to be true when I was testing screens near the end of my room construction. I had "bare dry wall primer" on the wall. Beautiful stuff that dries to eggshell smoothness and color. I then taped screen samples including the carada bw, high power, grays and some unity gain, to the primed wall. The primed wall looked great. The BW appeared to be the same as the primer as it just disappeared on the wall. The 1.0 screen samples were just slightly dimmer than the bw and primer.

Not only that, looking up close, the pixel definition was, if anything, crisper on the wall than on the screen material.

Nor can I notice much, if any, texture to the image on the wall either.

Is it possible the difference between projecting on a wall vs using a screen can be over-rated? (That is, unless you need a surface with more directional characteristics).

that's because the wall is a matte finish, like I've been saying all along, gain destroys picture detail and ultimate sharpness. Maybe it's not too late to change your material to Studiotek !00?

that's because the wall is a matte finish, like I've been saying all along, gain destroys picture detail and ultimate sharpness. Maybe it's not too late to change your material to Studiotek !00?

How close do you have to be to see the difference? Can you see it at 10 feet?

that's because the wall is a matte finish, like I've been saying all along, gain destroys picture detail and ultimate sharpness. Maybe it's not too late to change your material to Studiotek !00?

I've been saying that for the whole time I've been a member a year ago. Your best bet for a screen is to use a titanium oxide gesso, such as Tri-Art. You won't be able to beat it for the price, and the screens which do, will only beat it barely but you'll have to pay several thousand for what only costs a couple hundred for a DIY gesso.

How close do you have to be to see the difference? Can you see it at 10 feet?

Art grade gesso is so smooth, you need to put your nose to the screen to see the gesso brush brush marks. It's like you poured on a liquid covering. You can't see it at all. No sparkles, and a very white white. I think if most people saw gesso screens for sale done professionally, no one would buy any other screen. Except Mr. High Power fan boy extreme, who knows I'm talking about him! :D

Art grade gesso is so smooth, you need to put your nose to the screen to see the gesso brush brush marks.

I don't like to sit that close.

I don't like to sit that close.

Then you won't see my brushmanship :(

that's because the wall is a matte finish, like I've been saying all along, gain destroys picture detail and ultimate sharpness. Maybe it's not too late to change your material to Studiotek !00?

The thing is, in practice, I do not find that to be so. In general the same image made brighter will also tend to appear sharper. I've tested out the Stewart ST130 against neutral gain screens and while up close the pixels look very similar, if anything the edge to the neutral gain screens, from further away I find it easier to see the detail of the picture on the slightly higher gain screen and it appears a tad sharper.

Along the same continuum, I'm amazed at what a very high gain screen like the Da Lite High Power screen does for an image, when compared to a neutral gain screen. It makes the image look super sharp and detailed, like getting a new display (I've done the comparison several times with my HP screen and with other people's HP screen compared to neutral gain screens).

So, at least in my experience, whatever minimal precision may be lost at the pixel level (if there is indeed any of consequence) seems to be quite made up for by the increased visible detail and apparent sharpness in actual images, when I add gain.
(At least with some gain screens).

In general the same image made brighter will also tend to appear sharper.

Agreed. Brighter always appears subjectively to have more detail. On the down side, brightness can make the screen surface noticeable, and high APL scenes can be literally painful when transitioning from low APL scenes.

Agreed. Brighter always appears subjectively to have more detail. On the down side, brightness can make the screen surface noticeable, and high APL scenes can be literally painful when transitioning from low APL scenes.

I believe contrast sensitivity increases with brightness, at least upto a certain luminance level, then increased luminance has little effect. Projects would be within this increasing luminance increases contrast sensitivity area. As contrast sensitivity increases the curve gets taller and is sharper at the top, so the details you become most sensitive too, naturally focus on become smaller. While at dimmer luminance levels the curve drops and flattens out becoming relatively less concentrated on small details and more intrested in larger details.

I believe contrast sensitivity increases with brightness, at least upto a certain luminance level,

I seem to remember reading that to be the case at one time.

I notice this with my LCD computer monitor too. After a while it goes into an energy saving mode and dims the brightness a bit. When it does this the contrast becomes perceptually "worse" and text gets a bit harder for me to read.

The thing is, in practice, I do not find that to be so. In general the same image made brighter will also tend to appear sharper. I've tested out the Stewart ST130 against neutral gain screens and while up close the pixels look very similar, if anything the edge to the neutral gain screens, from further away I find it easier to see the detail of the picture on the slightly higher gain screen and it appears a tad sharper.

Along the same continuum, I'm amazed at what a very high gain screen like the Da Lite High Power screen does for an image, when compared to a neutral gain screen. It makes the image look super sharp and detailed, like getting a new display (I've done the comparison several times with my HP screen and with other people's HP screen compared to neutral gain screens).

So, at least in my experience, whatever minimal precision may be lost at the pixel level (if there is indeed any of consequence) seems to be quite made up for by the increased visible detail and apparent sharpness in actual images, when I add gain.
(At least with some gain screens).

Agreed. The first thing I noticed when going from a matte white painted screen to the Dalite High Power was a big increase in sharpness. As far as screen texture goes I do see it fairly easily on my High Power though, but that's only with solid white objects and sitting one foot under the projector lens. It's probably my main issue with this screen but having said that I did try going back to a neutral gain surface recently and I hated it, so I'm very content to stay with Dalite HP regardless of this minor issue.

that's because the wall is a matte finish, like I've been saying all along, gain destroys picture detail and ultimate sharpness. Maybe it's not too late to change your material to Studiotek !00?

Eh?

Detail pertains to the resolvable pixel characteristics. Sharpness has to do the withe clarity with which each pixel is displayed.

Neither of those has to do directly with gain, which simply trades light reflected on one axis for light reflected in another, hence making said pixels brighter.

The same sharpness and detail in those pixels will be present, only brighter. And some research suggests that lifting the picture up in brightness makes it easier for our eyes to see small detail.

Now if you are saying some screens scarifice detail because they aren't smooth, have optical coatings you don't like, etc... that's a different story. But that's not simply "gain", as you specify.

My understanding is perception of sharpness is to do with modulation transfer function and contrast sensitivity function. As brightness increases the viewers contrast sensitivity increases, the perceive the same contrast as if it is higher contrast, and the area of most contrast sensitivity shifts from being relatively equally focused on large and small areas to being more focused on small areas.
Higher resolution does not automatically translate into a sharper appearing image. To look sharper it has to increase contrast in the details, particularly those in the contrast sensitivity function, having more detail present does not on its own improve the perception of sharpness.
So a smooth flat matt wall might resolve more fine detail of the internal pixel structure like the edges of the dlp chip and the contour of the dimple in the middle, than a fabric screen with a bit of texture to it. But if the fabric screen is higher gain it will be perceived as giving a sharper image despite resolving less fine detail.

I don't find detail to be lacking at all on my Firehawk G3. With either my dVision 1080p single chip ( at around 16 foot lamberts ) or the new Lumis ( at around 20 foot lamberts ). The detail from good Blu Ray / HD DVD transfers is extraordinary !!

My <8ftL screen, looks plenty bright enough to me. But the reason I prefer it is probably because my projector does not have a dynamic iris, and only has a native contrast ratio of about 4000+:1, my screen is also matt white painted wall not grey with directional gain. So black level is more important to me than white level. As perception of white level seems to be more relative than perception of black level, and good black level gives the image the appearance of depth - solidity - realism.
With a high contrast directional gain screen, and a dynamic iris I would imagine you can get realistic enough black level while enjoying a higher white level.

My <8ftL screen, looks plenty bright enough to me. But the reason I prefer it is probably because my projector does not have a dynamic iris, and only has a native contrast ratio of about 4000+:1, my screen is also matt white painted wall not grey with directional gain. So black level is more important to me than white level. As perception of white level seems to be more relative than perception of black level, and good black level gives the image the appearance of depth - solidity - realism.
With a high contrast directional gain screen, and a dynamic iris I would imagine you can get realistic enough black level while enjoying a higher white level.

I think that is true. The Lumis with it's high on / off and ANSI contrast looks very 3 dimensional and blacks still look black.

Watching The Last Samurai on HD DVD monday followed by Valkyrie on Blu Ray last night, I have found that even at 20+ FL, whether the screen surface is visible is very material dependent. I didn't notice any screen surface texture for probably 98% of those films.