Official BenQ HT2050/W1110 Owner/Settings Thread - Page 57 - AVS Forum | Home Theater Discussions And Reviews
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post #1681 of 1716 Old 08-18-2019, 01:15 PM
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Originally Posted by NxNW View Post
I would dearly love to see the source you've been reading that leads to this last conclusion.



The basic analogy I think of is like sculpting a specific shape out of a shapeless chunk of marble: an uncalibrated projector can make a lot of light but its not very accurate. (Consider how pleasant it is to watch the 2050's "Bright" mode.) The process of calibration involves "chipping away" the machine's inaccurate behaviors. Inevitably this involves trading off raw light output for accuracy. Always. Green light seems really bright but if it makes everything green, you do something to make it less green. Now everything looks better. And darker. That's calibration in a nutshell.



(True, in the middle of the applicable adjustment ranges, you can "reduce" the effect of an overly green condition by simply increasing red and blue to restore balance, but at the high end of the range you can't do this, it just drives the machine beyond its capabilities and causes inaccuracies that are even worse.)



There is no part of calibration, that I know of, that involves making a projector brighter. The exceptions to this rule are really rare and I can't think of any off the top of my head.



To keep the analogy going, you try to chisel away only what you need to reveal the perfect sculpture you had in mind *in its biggest possible size*. You don't continue chiseling and make a dwarf version of the same shape. If you do that, you should have just saved your money and started with a smaller block of marble.


People generally watch projectors as bright as they will reasonably go (or at least as bright as their tolerance for inaccuracy will allow). Never dimmer. Not on purpose.


So I've never heard of the ability to take a projector that has been optimized to put out a good picture and then just suddenly increase its brightness after it's been calibrated. At least not without undoing some aspect of the calibration. You can always make a picture brighter and less acurate, never birgter while maintaining accuracy.


People instinctively love brightness, make no mistake, and many times you make a change and people's taste for brightness will lead them to pronounce the result "better", but there was probably a tradeoff somewhere that makes things less faithful to the original image that was encoded in the signal.



When people calibrate their projectors, the results will generally be the same no matter what surface they are shining the projector on, unless there's a pronounced color shift or something. The surface is a "given" - your only task is to optimize the things you *can* change.



Shining a previously calibrated projector on a darker screen only has one effect: the image gets darker. There's isn't some button you can press that allows the projector to get you back up to your old experience. If it was calibrated right, there's nowhere left to go. It's already at the optimal balance of brightness and accuracy. You can't add rock to the original chunk of marble to allow a bigger result of the same shape.



Anyway, back to the specific topic at hand, ie how bright is a reasonably good looking picture on a HT2050 when it is new, your calculations seem to satisfy you that my real world measurements are in the same ballpark as one of the reviewers. I agree.



I'm not sure it's easy to directly measure lumens. The required device looks pretty formidable (see image here https://i.stack.imgur.com/MJqAP.jpg) The best you can do is measure some other related property and go from there.



In this case, if the thing being measured is reflected light off of the screen surface, then the screen gain seems to have to enter the calcluation.



We can avoid that extra wrinkle by taking a measurement with the meter *facing* the lens. This results in a quantity with different units, lux, not cd/m2, but can still be used to get at the original thing your after, lumens. I think I have a few readings taken this way somewhere, or I can make some new ones if you think that would be helpful?
https://www.avsforum.com/forum/23-sc...op-whites.html

Calibration is probably the wrong term. In the thread above it says to get a negative gain screen to reflect the same amount of light as a 1.0 screen, the lumens of the projector need to be increased. I assume that is via the Brightness/Contrast sliders? These would alter the image's brightness/contrast, so to make sure it's right a 16-235 greyscale template has to be used?

My experience is with using the 16-235 greyscale template to "calibrate(?)" Normal and Eco lamp modes. The brightness/contrast would be higher in Eco mode.

Are the measurements taken facing the projector older, (lamp hours)?
It would be great if could take some new ones.
Thank you.
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post #1682 of 1716 Old 08-18-2019, 04:31 PM
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Quote:
Originally Posted by noob00224 View Post

https://www.avsforum.com/forum/23-sc...op-whites.html

Calibration is probably the wrong term. In the thread above it says to get a negative gain screen to reflect the same amount of light as a 1.0 screen, the lumens of the projector need to be increased. I assume that is via the Brightness/Contrast sliders? These would alter the image's brightness/contrast, so to make sure it's right a 16-235 greyscale template has to be used?

My experience is with using the 16-235 greyscale template to "calibrate(?)" Normal and Eco lamp modes. The brightness/contrast would be higher in Eco mode.

Are the measurements taken facing the projector older, (lamp hours)?
It would be great if could take some new ones.
Thank you.
That's a really great thread you cited there! However, I noticed that nowhere in the thread does the word 'dollars' appear. There were several sentences that contained something along the lines of 'increase lumens'. One guy literally said if you want to have a certain result, then 'crank up the lumens', as if there's some dial on the side of every projector marked 'Lumens' . If only.

All of the people that participated in that thread I believe are well respected contributors on AVS. Each of them, when speaking collegially about the concept of "increasing lumens..." left off the implied phrase "...as a determining factor in your buying decisions."

If you go back and re-read it with that in mind you'll see where I'm coming from.

Lumens are a fixed attribute that cannot be increased after the fact.

The only tool I know of that gives a brighter image than the one coming from your existing, calibrated projector is a credit card.

They are *not* taking about adjusting the value of any user controls on a calibrated projector.

Meanwhile, several times you've mentioned the range 16-235. Perhaps there is some additional confusion as to the purpose of a setting found on almost all displays, projector or fixed panel, that lets you choose between two ways of decoding 8-bit values in the signal, ie PC levels (0-255) vs video levels (16-235). That's a one-time adjustment, and is only driven by the behavior of whatever source(s) that you are plugging into the projector. Once you have determined which setting is correct for compatibility between the two devices talking to each other via a particular input, you never think about that again. It is not an elective choice you can revisit later in hopes of improving the image. There is only one right answer for each source that you connect, and getting the answer wrong will look terrible. In no case does it allow the projector to access some previously unused level of light output.

Lumens is essentially equivalent to watts, only multiplied by a numeric characterization of the human visual system's sensation of perceived lightness in certain wavelengths of electromagnetic radiation. But ultimately it's watts.

There is no setting on a 1500 watt hair dryer that allows it to suddenly become a 1700 watt hair dryer. That's actually illegal (for electrical safety reasons). That's not to say that you can never have a 1700 watt hair dryer. They do exist. But the only way to get that level of performance is to replace your 1500 watt hair dryer using your credit card.

The lamp-facing measurements are fairly recent. I'll post some when I get a chance.
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post #1683 of 1716 Old 08-18-2019, 04:56 PM
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Originally Posted by NxNW View Post
That's a really great thread you cited there! However, I noticed that nowhere in the thread does the word 'dollars' appear. There were several sentences that contained something along the lines of 'increase lumens'. One guy literally said if you want to have a certain result, then 'crank up the lumens'.

All of the people that participated in that thread I believe are well respected contributors on AVS. each of them, when speaking about the concept of "increasing lumens..." left off the implied phrase "...as a requirement in your buying decisions."

If you go back and re-read it with that in mind you'll see where I'm coming from.

Lumens are a fixed attribute that cannot be increased after the fact.

The only tool I know of that gives a brighter image than the one coming from your existing, calibrated projector is a credit card.

They are *not* taking about adjusting the value of any user controls on a calibrated projector.

Several times you've mentioned the range 16 - 235. Perhaps there is some additional confusion as to the purpose of a setting found on almost all displays that lets you choose between two ways of decoding 8-bit values in the signal, ie PC levels (0-255) vs video levels (16-235). That's a one-time adjustment, and is only driven by the behavior of whatever source(s) that you are plugging into the projector. Once you have determined which setting is correct for compatibility between the two devices talking to each other via a particular input, you never think about that again. It is not an elective choice you can revisit later in hopes of improving the image. There is only one right answer for each source that you connect, and getting the answer wrong will look terrible. In no case does it allow the projector to access some previously unused level of light output.

Lumens is essentially equivalent to watts, only modulated against the human visual system's response to perceived lightness in certain wavelengths. But ultimately it's watts.

There is no setting on a 1500 watt hair dryer that allows it to suddenly become a 1700 watt hair dryer. That's actually illegal (for electrical safety reasons). That's not to say that you can never have a 1700 watt hair dryer. They do exist. But the only way to get that level of performance is to replace your 1500 watt hair dryer using your credit card.

The lamp-facing measurements are fairly recent. I'll post some when I get a chance.
Thanks for explaining.
When it said increase the lumens, I took it literally, and was searching for ways to do that.
Curious to see what the gain of the screen is. Would like to check my screen as well, but would need colorimeter or luxmeter.
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post #1684 of 1716 Old 08-21-2019, 11:43 AM
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I have an L-shaped room with an 82" screen for my HT2050a. I made a few room treatments on the screen side of the room (darker walls, some velvet on the ceiling and surrounding areas), but the back of the room is still a light tan with white ceilings because the room is mixed-use. This made a huge difference in the colors popping in bright scenes, but now the black levels in dark scenes just don't seem very black when watching at night and the contrast should be at its highest. I don't notice it as much during the day for obvious reasons.

I didn't know much about HT when setting up my theater, so I went with an 82" screen because it seemed to fit the wall size. I could go a little larger if I wanted. I put the projector right at seating distance about 7.5/8 feet. The throw distance calculator says I could go as far back as about 11 feet.


My questions are these:

Is the back of the room simply causing too much reflection?

If I keep the same screen setup, is it worth moving the projector back as far as I can to use as little zoom as possible? I've read this helps with contrast. If so, will this really make that much of a difference on a HT2050a because of the 1.15-1.5 zoom ratio? 3 feet at best doesn't seem like a drastic change.

Does having a smaller screen actually hurt my black levels because of how close the projector has to be to the image? Would increasing the screen size and moving the projector back a little help with this?

I do plan on putting black blackout curtains on the doors and other window, which I'm sure will help a little. I have ran through pretty much every setting on the unit and can't get happy with the picture at presumably optimal viewing time (when it's dark outside). Please see the attached pictures (and yes I did eventually fix the keystone haha).

Thank you for your thoughts.
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post #1685 of 1716 Old 08-21-2019, 06:49 PM
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I have an L-shaped room with an 82" screen for my HT2050a. I made a few room treatments on the screen side of the room (darker walls, some velvet on the ceiling and surrounding areas), but the back of the room is still a light tan with white ceilings because the room is mixed-use. This made a huge difference in the colors popping in bright scenes, but now the black levels in dark scenes just don't seem very black when watching at night and the contrast should be at its highest. I don't notice it as much during the day for obvious reasons.

I didn't know much about HT when setting up my theater, so I went with an 82" screen because it seemed to fit the wall size. I could go a little larger if I wanted. I put the projector right at seating distance about 7.5/8 feet. The throw distance calculator says I could go as far back as about 11 feet.


My questions are these:

Is the back of the room simply causing too much reflection?

If I keep the same screen setup, is it worth moving the projector back as far as I can to use as little zoom as possible? I've read this helps with contrast. If so, will this really make that much of a difference on a HT2050a because of the 1.15-1.5 zoom ratio? 3 feet at best doesn't seem like a drastic change.

Does having a smaller screen actually hurt my black levels because of how close the projector has to be to the image? Would increasing the screen size and moving the projector back a little help with this?

I do plan on putting black blackout curtains on the doors and other window, which I'm sure will help a little. I have ran through pretty much every setting on the unit and can't get happy with the picture at presumably optimal viewing time (when it's dark outside). Please see the attached pictures (and yes I did eventually fix the keystone haha).

Thank you for your thoughts.

I've seen it said that positioning the projector closer increases ANSI contrast, and further FOFO contrast.

The closer a projector sits to the screen the brighter the image will be. The larger the diagonal the dimmer the image will be.
You can take it out of the ceiling, put it on a table and move it back, but I doubt it will make up the difference you want in blacks.

The room has better than average reflection reduction, and not sure if more will help in a significant way with this projector.

If you want to reduce the reflections in the room further and don't want to add velvet to the walls something like this would be an option:
https://www.facebook.com/projectiond...2721894385217/
A good read on the effect reflections have on contrast:
https://projectiondream.com/en/contr...r-environment/

Have you tried ECO lamp mode?
Disable Brilliant Color.

To reduce projector lumen output a ND filter or a grey screen ca be used. This will make the blacks darker, but also the whites/colors.
You can research negative gain screens, here's a start: https://www.avsforum.com/forum/23-sc...op-whites.html

Every setup is different, and so is the user, but what it sounds like a projector with better black level would be more appropriate here. The cheapest would be Sony 45ES and Epson 5040UB, both refurbished.
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post #1686 of 1716 Old 08-22-2019, 10:46 AM
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I've seen it said that positioning the projector closer increases ANSI contrast, and further FOFO contrast.

The closer a projector sits to the screen the brighter the image will be. The larger the diagonal the dimmer the image will be.
You can take it out of the ceiling, put it on a table and move it back, but I doubt it will make up the difference you want in blacks.

The room has better than average reflection reduction, and not sure if more will help in a significant way with this projector.

If you want to reduce the reflections in the room further and don't want to add velvet to the walls something like this would be an option:

A good read on the effect reflections have on contrast:


Have you tried ECO lamp mode?
Disable Brilliant Color.

To reduce projector lumen output a ND filter or a grey screen ca be used. This will make the blacks darker, but also the whites/colors.
You can research negative gain screens, here's a start:

Every setup is different, and so is the user, but what it sounds like a projector with better black level would be more appropriate here. The cheapest would be Sony 45ES and Epson 5040UB, both refurbished.
I disabled Briliant Color and turned on Smart ECO at your suggestions and made a surprising difference. The picture now also looks more natural. I did forget to mention the screen is made with Carl's FlexiGray, which was lighter than other grays and I felt was a good medium. I plan on sticking with this projector for the foreseeable future while we're in our current house, but I will definitely look a little higher end on my next setup. I'll check those links out too. Thank you!
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post #1687 of 1716 Old 08-22-2019, 03:01 PM
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..the black levels in dark scenes just don't seem very black .. I have ran through pretty much every setting on the unit and can't get happy with the picture at presumably optimal viewing time (when it's dark outside).
noob already responded really thoroughly and I agree with all that, but could i just do a quick sanity check here?

- What is your setting for "brightness"
- How did you arrive at this setting?
- Same for HDMI Format (Video vs PC)
- By any chance do you have access to an instrument that can measure the light coming off of regions of the screen that are supposedly displaying a pure black signal

If your brightness is at 50 (and you don't have a video range mismatch with your source) you're probably done. Blacks are what they are, sit back and enjoy, maybe you can get a little improvement from additional room treatment or a (much) more expensive projector.



If a light meter shows less than 0.020 FtL for black, you're definitely done. Best I ever got from a 2050 was 0.009; 0.020 is great in a medium-blacked-out room.
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post #1688 of 1716 Old 08-22-2019, 04:58 PM
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I disabled Briliant Color and turned on Smart ECO at your suggestions and made a surprising difference. The picture now also looks more natural. I did forget to mention the screen is made with Carl's FlexiGray, which was lighter than other grays and I felt was a good medium. I plan on sticking with this projector for the foreseeable future while we're in our current house, but I will definitely look a little higher end on my next setup. I'll check those links out too. Thank you!
The lamp setting with the lowest light output is ECO, SmartECO is a dynamic mode between ECO and Full depending on the scene.
While the SmartECO/lamp dimming feature has been measured in reviews, and it indeed works (power drawn from socket also varies), visually I can't tell the difference between Full and SmartECO.

As @NxNW said, check the color space settings to make sure they are correct. From the projector and the source.
There is a free disc available, the Brightness and Contrast pattern are the 2 templates used: https://www.avsforum.com/forum/139-d...libration.html
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post #1689 of 1716 Old 08-23-2019, 10:58 AM
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noob already responded really thoroughly and I agree with all that, but could i just do a quick sanity check here?

- What is your setting for "brightness"
- How did you arrive at this setting?
- Same for HDMI Format (Video vs PC)
- By any chance do you have access to an instrument that can measure the light coming off of regions of the screen that are supposedly displaying a pure black signal

If your brightness is at 50 (and you don't have a video range mismatch with your source) you're probably done. Blacks are what they are, sit back and enjoy, maybe you can get a little improvement from additional room treatment or a (much) more expensive projector.



If a light meter shows less than 0.020 FtL for black, you're definitely done. Best I ever got from a 2050 was 0.009; 0.020 is great in a medium-blacked-out room.
Brightness is actually at 49 most of the time because the blacks were bothersome. I guess I don't have any other options. It will be worth looking into a higher-end projector in the future, but for now I guess I'm satisfied. I was just curious if there were any things I could do to maximize the picture.
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post #1690 of 1716 Old 08-23-2019, 12:44 PM
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Brightness is actually at 49 most of the time because the blacks were bothersome. I guess I don't have any other options. It will be worth looking into a higher-end projector in the future, but for now I guess I'm satisfied. I was just curious if there were any things I could do to maximize the picture.
Only things I can think of at this point are , again, sanity check, you are talking about lights off right? You say "at night" but of course that doesn't mean anything if you have the lights on. Also you may want to check that your gamma is not some unusual setting like "1.8" or "BenQ". 2.2 is the default and it's a good one. If you bump it a little higher, darker areas of the image will be.. darker .. but with possible loss of shadow detail. Your call. I leave it at 2.2 unless I've got some lights on or I'm watching something non critical like sports.

Finally, you don't mention if you have some other display elsewhere in the house like an OLED or something that may be leading to unreasonable expectations. Some flat panels can get real dark these days, and holding a sub-$600 (current value on ebay) projector to that standard is not a fair comparison.
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post #1691 of 1716 Old 08-23-2019, 01:53 PM
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Are the measurements taken facing the projector older, (lamp hours)?
It would be great if could take some new ones.
Thank you.
You know this whole lumens thing really got me going on a huge research project and I discovered a lot of things.

But the one thing worth sharing is there's a dead simple formula commonly used in the home theater world that removes a lot of variables from the very science-based approach I was obsessing about earlier.

Besides knowing the dimensions of your screen, the formula requires just one input:

A measurement, in lux, of a 'white' test pattern, taken facing the projector lens, *with the meter's lens in the exact plane of the screen surface*.

This last bit is surprisingly hard to accomplish.

First, real world meters have a lens that is contained in a boxy enclosure with some kind of non-negligible depth. Even placing the back of the meter in contact with the screen surface puts the lens an inch or more closer to the projector than the actual screen is, and this changes the outcome. You could maybe go off to the side somewhere but the screen sorta by definition occupies all areas that are lit up by the projector so now you're in the dark. There's also uniformity issues: real world projectors unfortunately may send measurably more light to the northwest part of the imaging area than the southeast part etc. Somewhere near the dead center of the image is probably where you'll get the highest values (I know I did, and I searched pretty thoroughly). Lastly, the orientation of the meter matters somewhat, since you may get higher or lower readings based on whether the enclosure is being held horizontally or vertically or not pointed exactly straight at the projector, etc. Basically you try em all while taking continuous readings and just record the max value you get.

So last night I reset everything (this time zooming the image to the other end of the zoom range, sorry) and tore up the room and hunted around for the brightest possible readings in various locations and made some new measurements. Then I plugged them into this formula:

Code:
lumens = (lux / 10.76) * area of screen in sq ft
If you stay in metric that's simply

lumens = lux * area of screen in sq meters

I got this formula from the surprisingly helpful thread
https://www.avsforum.com/forum/24-di...projector.html
which is still relevant 13 years later.

By the way, regarding an earlier question you asked, can you determine screen gain using a light meter, I found this site helpful http://bnoack.com/light/illuminance.html

That page basically lays out another dead simple formula,

lux = pi * nits (assuming a perfect 1.0 gain surface)

Rearranging the terms and properly accounting for gain I get:

gain = (nits * pi) / lux

Again, this supposes you are using two very well-matched readings from the same spot on the screen. Every other method based on a meter reading taken in some other way is a compromise and starts to involve a lot of math.

Final disclaimer, I took these values using a white full field pattern instead of a smaller window pattern centered on the reading location. That brings all the room reflections into play.

So even trying as hard as I could to simplify, these values are contaminated somewhat and you can't pretend there's much precision in the result. Maybe I'll repeat this whole process someday with tiny test patterns and black felt everywhere, but anyway here are the numbers from last night:

I got 236 lux facing the PJ, taken from the exact plane of the screen.
The area of the image being thrown was 4.10 meters-squared

By my calculations that comes to 967 lumens (with a 1900 hour old lamp mind you).

I also got 48.5 nits measured facing the other way, pointed at the exact same part of the screen where the meter was for the first measurement.

So that led to a shockingly low computation for gain, 0.65

I was willing to believe it might be as low as 0.85 but 0.65? Yikes. I think I'll go buy a "white" screen knowing the gain's going to end up being way lower than whatever the manufacturer claims.

But that's my problem, not yours. The general takeaway for HT 2050 owners is even a bulb in the middle of its lifespan still gives around 1000 calibrated lumens. Good stuff.
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post #1692 of 1716 Old 08-23-2019, 02:50 PM
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You know this whole lumens thing really got me going on a huge research project and I discovered a lot of things.

But the one thing worth sharing is there's a dead simple formula commonly used in the home theater world that removes a lot of variables from the very science-based approach I was obsessing about earlier.

Besides knowing the dimensions of your screen, the formula requires just one input:

A measurement, in lux, of a 'white' test pattern, taken facing the projector lens, *with the meter's lens in the exact plane of the screen surface*.

This last bit is surprisingly hard to accomplish.

First, real world meters have a lens that is contained in a boxy enclosure with some kind of non-negligible depth. Even placing the back of the meter in contact with the screen surface puts the lens an inch or more closer to the projector than the actual screen is, and this changes the outcome. You could maybe go off to the side somewhere but the screen sorta by definition occupies all areas that are lit up by the projector so now you're in the dark. There's also uniformity issues: real world projectors unfortunately may send measurably more light to the northwest part of the imaging area than the southeast part etc. Somewhere near the dead center of the image is probably where you'll get the highest values (I know I did, and I searched pretty thoroughly). Lastly, the orientation of the meter matters somewhat, since you may get higher or lower readings based on whether the enclosure is being held horizontally or vertically or not pointed exactly straight at the projector, etc. Basically you try em all while taking continuous readings and just record the max value you get.

So last night I reset everything (this time zooming the image to the other end of the zoom range, sorry) and tore up the room and hunted around for the brightest possible readings in various locations and made some new measurements. Then I plugged them into this formula:

Code:
lumens = (lux / 10.76) * area of screen in sq ft
If you stay in metric that's simply

lumens = lux * area of screen in sq meters

I got this formula from the surprisingly helpful thread
https://www.avsforum.com/forum/24-di...projector.html
which is still relevant 13 years later.

Regarding an earlier question you asked, can you determine screen gain using a light meter, there's another formula mentioned in that thread I found intriguing: once you have this screen-facing, in-plane measurement in lux, you can compare it to the reading you're getting *facing the screen* in Foot Lamberts (both readings should involve the exact same location within the image as much as possible-- see note above about image uniformity). The two readings should be related by the formula

Code:
ftL = lumens * screen gain / (area of screen in sq ft)
This works fine, but I was starting with metric numbers. So I prefer to use a simpler formula that states nits = lux / pi (assuming a perfect 1.0 gain surface)

Using a little junior high algebra I get

gain = (nits * pi) / lux

Again, this supposes you are using two very well-matched readings from the same spot on the screen. Every other method based on a meter reading taken in some other way is a compromise and starts to involve a lot of math.

Final disclaimer, I took these values using a white full field pattern instead of a smaller window pattern centered on the reading location. That brings all the room reflections into play.

So even trying as hard as I could to simplify, these values are contaminated somewhat and you can't pretend there's much precision in the result. Maybe I'll repeat this whole process someday with tiny test patterns and black felt everywhere, but anyway here are the numbers from last night:


I got 236 lux facing the PJ, taken from the exact plane of the screen.
The area of the image being thrown was 4.10 meters-squared

By my calculations that comes to 967 lumens (with a 1900 hour old lamp mind you).

I also got 48.5 nits measured facing the other way, pointed at the exact same part of the screen where the meter was for the first measurement.

So that led to a shockingly low computation for gain, 0.65

I was willing to believe it might be as low as 0.85 but 0.65? Yikes. I think I'll go buy a "white" screen knowing the gain's going to end up being way lower than whatever the manufacturer claims.

But that's my problem, not yours. The general takeaway for HT 2050 owners is even a bulb in the middle of its lifespan still gives around 1000 calibrated lumens. Good stuff.
Thanks for taking your time with the measurements.
Was the projector the closest to the screen or furthest? PC claims the difference in brightness from one end to the other is 27%.
They measured 1160 lumens with Cinema, Full lamp, widest lens position (closest to the screen), no BC, (gamma 2.2?).
If the lamp looses 20% of it's brightness in the first few hundred hours not sure how it measured 967 lumens.
I don't know what method PC used, or what is the standard process for measuring lumens. It should matter the distance from the screen, and it's not specified. Link
In this review link the result was 1198 lumens (with a settings above) for an 110" screen I think.
Maybe I'm missing something about the test procedure. How are these measurements taken, is the meter placed in front of the screen or next to the lens to eliminate the distance variable?
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post #1693 of 1716 Old 08-23-2019, 03:13 PM
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Quote:
Originally Posted by noob00224 View Post
Thanks for taking your time with the measurements.
Was the projector the closest to the screen or furthest? PC claims the difference in brightness from one end to the other is 27%.
They measured 1160 lumens with Cinema, Full lamp, widest lens position (closest to the screen), no BC, (gamma 2.2?).
If the lamp looses 20% of it's brightness in the first few hundred hours not sure how it measured 967 lumens.
I don't know what method PC used, or what is the standard process for measuring lumens. It should matter the distance from the screen, and it's not specified. Link
In this review link the result was 1198 lumens (with a settings above) for an 110" screen I think.
Maybe I'm missing something about the test procedure. How are these measurements taken, is the meter placed in front of the screen or next to the lens to eliminate the distance variable?
I think you're asking about meter placement for other people's procedures, right? (I thought I described mine pretty clearly :> ) I can't comment on other reviewers procedures, I really don't know how they calculate lumens. I know sometimes when trying to determine "ANSI contrast ratio" (as described in the thread I linked to above) you put a meter very close to the projector in order to reduce the effects of room reflections (and to get higher, easier to measure levels for black, since all but the most expensive light meters get to be pretty unreliable at the very low end of their range). But I doubt people do that for lumens.



As for my projector placement, sorry I didn't explicitly mention that it had not moved from the mounting location implied from the measurements taken a few days ago. Interestingly I measure this distance as 10'5" from the top edge of the screen surface to the front surface of the projector lens, but projector central's results match my setup's observed geometry best when plugging a mounting distance of 10'2" into their calculator for whatever that's worth. Anyway for me last night yes, Cinema, full lamp power, widest lens position (closest allowable to the screen for a 106.3"x59.8" image), no BC, gamma 2.2, and also, while we're at it, white calibrated to D65, and, more pertinent to raw light output, contrast still set to the default value of 50.


Using your formula of 20% decrease in 500 hours, 50% after 7000 hours, I plot those points on a graph, fit a logarithmic curve to them, and then use a straightedge to see where 1900 hours would fall on that curve and I get around 64% of new.
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post #1694 of 1716 Old 08-25-2019, 10:36 PM
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A good article on measuring lumens :

https://www.projectorcentral.com/Lumens-Explained.htm


the one above is much better written than this article below which i do *not* recommend https://www.lifewire.com/understandi...htness-4125499
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Pushing right over 14,000 hours now,...….first bulb almost hit 9000 hours, second one is right over 5,000 hours now.



Projector has been flawless and still looks outstanding...….


I think they would consider this industrial use for right under 3 years usage...…..



PJ price plus the new bulb puts it at approx. 15 cents a hour or 30 cents a movie...…...but not all movies are 2 hours, so I just say a quarter per movie.
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Speakers and subs for sale...https://www.avsforum.com/forum/209-au...kers-subs.html

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nice. i only have 5k hours on my W1070+.
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Does anyone know exactly what the BenQ gamma setting does? I found a few people in the thread discussing it, but no definitive answers yet. No luck Googling yet either.
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Quote:
Originally Posted by CutItDown View Post
Does anyone know exactly what the BenQ gamma setting does? I found a few people in the thread discussing it, but no definitive answers yet. No luck Googling yet either.
Ah, just found a possible answer...

"Default gamma in Vivid TV is set to BenQ which is also know as an ‘S’ curve that overly lowers the dark end and overly brightens the high end of the grayscale making for a more contrasty picture." -- on projectorreviews.com[slash]benq/benq-ht2550-4k-uhd-home-theater-projector-review-calibration-settings/
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Brightness Uniformity problems

Has anyone experienced brightness uniformity issues with their DLP projector? I own a BenQ HT2050 projector and always run it in SmartECO mode to help prolong bulb life as much as possible, and keep the lens clean at all times. Anyways, I recently mounted this projector on a wall mount behind the seating area. It is inverted when on the mount. This would put it about the same height as when using a ceiling mount. After doing this, there was a noticeable brightness uniformity problem on the front wall the image was projected onto, with the left side being much brighter than the right side (which was darker). I then placed the projector, right side up, on a laptop stand right behind the seating area. The projector's height was about slightly above the back of the couch. This time brightness uniformity was a lot better, and a lot more even. You can notice slight more brightness on the right side of the wall and little darker on the left side, but it is not very noticeable or distracting when watching content. The projector was exaclty in the same place - direct center - when either on the wall/ceiling mount and when on the stand. Can someone explain why this is, and has anyone exerpienced this before? Is there anything that can be done to help brightness uniformity when the projector is on the wall mount? Thanks very much
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post #1700 of 1716 Old 09-09-2019, 08:33 AM
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It sounds like you are using your front wall as a screen surface and there is nothing wrong with that, but the surface can be like different types of commercial screens and react to projected light differently depending on the projection angle and how our eyes are positioned to that angle. A painted wall with a slight sheen will cast the brighter image from an upper mount maybe below your eye line.

As to side to side brightness I don’t really know except sometimes a little change in the reflected ambient light off the room will lighten one side of the screen more than the other. Something like that maybe.

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post #1701 of 1716 Old 09-09-2019, 09:33 AM
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Hi guys. I just recently picked up the HT2050A as my first projector and now I'm shopping for screens.


I don't have the ability to completely black out my theater space -- the screen is going to be in the middle of a 25' wide wall, and about 1 ft. below a white ceiling, under a small bulkhead (which may reduce the glare). While the purpose of the setup is primarily going to be full movie immersion, it will occasionally be used for sports and video games, so there won't always be a total lack of ambient light.


While an ALR screen seems like a good idea, Elite recommends a distance between the screen and lens of 1.5x the width of the screen to cut down on hotspotting when using the CineGray 3D or 5D. I'm getting the feeling that meeting this spec is impossible with the HT2050A given its rather tight focusing range, and max wide angle of 1.3. Is my only recourse, then, a traditional CineGray/FlexiGray screen to minimize washout? I don't really have the means right now to spend thousands on a high end screen.
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Quote:
Originally Posted by pjl63 View Post
Hi guys. I just recently picked up the HT2050A as my first projector and now I'm shopping for screens.


I don't have the ability to completely black out my theater space -- the screen is going to be in the middle of a 25' wide wall, and about 1 ft. below a white ceiling, under a small bulkhead (which may reduce the glare). While the purpose of the setup is primarily going to be full movie immersion, it will occasionally be used for sports and video games, so there won't always be a total lack of ambient light.


While an ALR screen seems like a good idea, Elite recommends a distance between the screen and lens of 1.5x the width of the screen to cut down on hotspotting when using the CineGray 3D or 5D. I'm getting the feeling that meeting this spec is impossible with the HT2050A given its rather tight focusing range, and max wide angle of 1.3. Is my only recourse, then, a traditional CineGray/FlexiGray screen to minimize washout? I don't really have the means right now to spend thousands on a high end screen.
Not sure what you mean by 1.3. The HT2050A's throw range is between x1.15 and 1.5.

Pictures with a W2000(HT3050) almost identical to the HT2050A at x1.5 throw range, about 1000h hours on lamp, on Cinegrey 3D. Ceiling mounted.
https://www.avsforum.com/forum/68-di...l#post57673262

To cut down on cost Elite sells both the 3D and the 5D just the fabric in a tube, called Designer Cut, for under $200.
Carl's ALR is similar to the Elite and also sold in a tube. It's more aggressive than the 5D. The 5D was measured and it did not have 1.5 gain, but closer to 1:
https://www.accucalav.com/wp-content...een_report.pdf

A negative gain grey screen will absorb some of the light, not reflect it like an ALR. The grey screen will absorb some of the reflections from the walls, but also from the projector. Which means darker image (whites and colors, but deeper blacks), unless more lumens are thrown at the screen.
Discussion here: https://www.avsforum.com/forum/23-sc...op-whites.html

Good thread on ALR/grey screens:
https://www.avsforum.com/forum/23-sc...ey-screen.html

It is recommended that the room is modified in order to reduce reflections with paint or fabrics.
More info here:
https://www.avsforum.com/forum/24-di...image-217.html

Two very instructive links on this subject:
https://www.facebook.com/projectiond...2721894385217/
https://projectiondream.com/en/contr...r-environment/

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Quote:
Originally Posted by noob00224 View Post
Not sure what you mean by 1.3. The HT2050A's throw range is between x1.15 and 1.5.
Got that figure from the projector calculator on Projector Central.


https://www.projectorcentral.com/Ben...ulator-pro.htm

Going by their numbers regarding screen dimensions, my impression is thus:

I'm shooting for a 120" screen. At 1.5x, that means the projector would have to be 15 feet from the screen. According to the projector calculator, the screen diagonal at 15 feet is 138-180".


Am I doing these calculations correctly?
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Quote:
Originally Posted by pjl63 View Post
Got that figure from the projector calculator on Projector Central.


https://www.projectorcentral.com/Ben...ulator-pro.htm

Going by their numbers regarding screen dimensions, my impression is thus:

I'm shooting for a 120" screen. At 1.5x, that means the projector would have to be 15 feet from the screen. According to the projector calculator, the screen diagonal at 15 feet is 138-180".


Am I doing these calculations correctly?
The x1.3 is zoom factor. From x1.0 (no zoom) to x1.3 (30%) zoom (larger image).
The value ALR screens manufacturers quote as to how far away the projector needs to be relative to the screen is throw range, not zoom factor.

In the PC calculator set screen size at 120" (if this is the desired size) and click the lock next to it to keep it fixed at 120".

If the projector sits as close as possible, it's using maximum zoom (x1.3). Throw range at this distance x1.15.
If the projector sits as far as possible it's using no zoom (x1.0). Throw range at this distance is x1.5.

Where it says Zoom Range, setting it to Telephoto means less zoom, Wide angle means more zoom.

For an 120" screen minimum distance (with max zoom (x1.3) and throw range x 1.15) is 10 ft. But this is too close for the ALR screen. The maximum distance is 13ft 1 inch with no zoom (x1.0), which is x1.5 throw range. For ALR screens it's specified they must be at least x1.5 throw range from the screen.


The pictures above with the Cinegrey 3D are at throw range x1.5.

Elite's Director Cut 3D and 5D come in 135" 16:9 format, Carl's ALR can be ordered in larger sizes:
https://www.carlofet.com/shop/projec...22+%2845x80%29

Quote:
Originally Posted by unretarded View Post
Pushing right over 14,000 hours now,...….first bulb almost hit 9000 hours, second one is right over 5,000 hours now.



Projector has been flawless and still looks outstanding...….


I think they would consider this industrial use for right under 3 years usage...…..



PJ price plus the new bulb puts it at approx. 15 cents a hour or 30 cents a movie...…...but not all movies are 2 hours, so I just say a quarter per movie.

Nice.
My first bulb blew up at 3500h, with untreatable flickering on Eco,SmartEco and Full lamp in 3D from 2500h.
It's recommended that the lamp is kept on Full every once in a while to avoid this issue.

Are you keeping it on SmartEco all the time?

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post #1705 of 1716 Old 09-10-2019, 01:35 PM
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I see what you're talking about. I was going by screen diagonal rather than image width.


I may look for that screen material for a DIY project. Is the Carl's similar in quality to the Elite? I've found lots of reviews/info on the Elite, but not so much on Carl's.


Thanks for the help.
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Quote:
Originally Posted by pjl63 View Post
I see what you're talking about. I was going by screen diagonal rather than image width.


I may look for that screen material for a DIY project. Is the Carl's similar in quality to the Elite? I've found lots of reviews/info on the Elite, but not so much on Carl's.


Thanks for the help.
Throw range is calculated by the width of the screen, yes.

As it said in a post above, the 5D was measured and it did not have 1.5 gain, but closer to 1.0. I assume the Cinegrey 3D is lower than that. Unclear of Carl's.

Carl's ALR is very similar to the Cinegrey 5D. Even though both of these fabrics claim 1.5 gain, Carl's is more aggressive than the 5D. The materials have been upgraded over time, so not sure what the current status is.

More aggressive means that it probably has higher gain. The higher the gain the lower the viewing cone is, and the more accentuated visual artifacts ALR fabrics have manifest.

Possible artifacts are:

Hotspot. A brighter image in the center of the screen than the rest. They are noticeable on bright images.
In the link above with the W2000, in the picture with the Google front page the hotstpot can be seen.

Sparkle in the center of the screen. Can't see it from the pictures in the example above, but sparkles can be seen in very bright scenes in the center of the screen.


Some ALR screens have a lower viewing cone: A matte screen will have a viewing cone of about 160 degrees, in from which the light will be equally bright. An Cinegrey 3D for instance has 90 degree (45 left 45 right) viewing cone. Outside of that the brightness will diminish.
This chart is accurate when it comes to gain versus angle of viewing:
https://elitescreens.com/kcfinder/up...inChart(1).jpg

There are many videos/reviews of the Cinegrey 3D/5D online.
Carl's reivews: (in the Amazon link go below at the customer reviews, there are pictures)
https://www.avsforum.com/forum/23-sc...lr-review.html
https://www.amazon.com/Carls-Ambient.../dp/B018J2EH3G

As can be seen from user's pictures, these artifacts do not necessarily manifest themselves. They depend on the projector, it's brightness settings, the distance from the screen, the image being projected.
The example with the W2000 is relevant because it is almost identical with the HT2050A, and set at maximum throw range of x1.5. Lamp mode was SmartEco, but changing it to Eco did not diminish the artifacts. The fabric, Cinegrey 3D is less aggressive than the 5D and Carl's ALR, so the hotspot and sparkle would probably be more noticeable with these last 2.

Regardless if you go ahead with an ALR fabric, there is a mod that can be done on projectors with this chassis: between the optic bloc/cylinder and the plastic case there is some free space of about 5mm:https://i.ytimg.com/vi/27mj8qidxCg/maxresdefault.jpg
Blocking it with a wire of similar diameter can be done. The disadvantage is that you can't move the focus ring, and have to remove the wire for that. Light from the lamp comes out from here and washes out the image a bit. Blocking it on an ALR screen it is especially noticeable, especially because it contributes to the hotspot.

LE: Another budget option for a screen is paint, which can result in very good results. There is a DIY screen section with lots of useful information:
https://www.avsforum.com/forum/110-diy-screen-section/

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post #1707 of 1716 Old 09-12-2019, 01:27 PM
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I don't think any DLP projector has perfect uniformity, seems to vary between 75-90%, typically depending on cost. Light from the bulb necessarily strikes the DLP chip at an angle, brightness uniformity will then depend on how good the light engine (lenses/mirrors) are at focusing the incoming light onto the chip. I presume the side of the chip closest to the incoming light will be brighter if the rays of light aren't parallel.

Uniformity also varies due to manufacturing tolerances. Have heard of people sending units back to the manufacturer to get the internal lenses/mirrors fine tuned to improve uniformity. I had noticeable uniformity issues with one projector (not this brand), and sent it back within a week for a much better unit (same model). Still my favorite way to watch movies after 7 years of use.
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Quote:
Originally Posted by noob00224 View Post
Regardless if you go ahead with an ALR fabric, there is a mod that can be done on projectors with this chassis: between the optic bloc/cylinder and the plastic case there is some free space of about 5mm:https://i.ytimg.com/vi/27mj8qidxCg/maxresdefault.jpg
Blocking it with a wire of similar diameter can be done. The disadvantage is that you can't move the focus ring, and have to remove the wire for that. Light from the lamp comes out from here and washes out the image a bit. Blocking it on an ALR screen it is especially noticeable, especially because it contributes to the hotspot.
Pictures with the mod in the attachment.
In the last picture the ring is not perfectly flush with the case, but it can be.

Example of hotspot on similar Benq projectors:
https://www.avsforum.com/forum/23-sc...l#post58568560
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Hello fellow 'PJers',

Have not been particularly active on this board, although I visit and read from time to time.

I just completed a routine bulb change in my Benq W1110 (fw: 1.01).
I also did a thorough cleaning while at it (DLP engine+optical assembly).

Below are a few pictures of the inner workings of this great machine, for anyone interested.

Disassembled unit (after cleaning):



Board with Texas instruments DMD chip:


Color Wheel:


Optical assembly:



Sunon Blower:


Mains and Power Supply boards:


Cracked screw posts:



Reassembled:



This unit has served me really well all these years.
I have to acknowledge that I've never had another unit from any brand that lasted so long (and keeps going).
At the moment (after a 4th or 5th bulb), it has reached above 21500 hours.

To be more precise, it has counted 21747 hours:



So, the only weak point of the design were those screw posts for the optical assembly that you can see cracked at the pictures above.

They failed due to the stress from the screws themselves and mainly due to the heat being constantly dissipated at those spots. Ideally the should have used metal screw posts there.

But thankfully, it's a minor flaw.
Especially since the optical assembly & DLP engine are held securely by additional screws that are fixed on the top PCB.

Regardless, since I was on it, I proceeded to do some work on the screw posts just to be sure.
I used a Dremel tool to drill fresh holes at the cracked posts for new (longer and wider) screws.

All in all, kudos to Benq for presenting us with a finely engineered piece of equipment and at such a fair price!!
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Originally Posted by evonimos View Post

I just completed a routine bulb change in my Benq W1110 (fw: 1.01).
I also did a thorough cleaning while at it (DLP engine+optical assembly).

Below are a few pictures of the inner workings of this great machine, for anyone interested.
Just wow. Thank you so much for sharing these highly informative photos. I just bought a replacement bulb and I was feeling some apprehension about the installation process. Seeing these pictures makes me think it's going to be ok. And they're just cool for anyone interested in how DLP's work generally.

The first time i did serious work on an automobile engine I couldn't believe how complex it was, then when I put it back together and it actually ran I couldn't believe how simple it was!

Also totally amazed that you have been able to run this projector 25000 hours, ie the equivalent of three years. I don't think I've even owned mine that long - even if I ran it continuously I couldn't touch that number. 🙂

Anyway thank you again! Awesome post.
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