Number fudging with projectors and screens has been going on for years, I did buy a Mars Pro from Dangbei ,a when I read the figures of 3200 lumens ,I knew that could not be true. After reading and watching many reviews from a lot of different sources ,it came to be that the light output of the Dangbei Mar Por ,was really 1800-2000 true lumens depending on the quality of the screen .The question here is why did Epson get involved in this debate ,when they themselves have contrast number off on some of there projectors .Which I have owned (2) .When it gets right down to it ,it's picture quality over price .After watching several hours with the single laser light of the Dangbei ,I can see why Epson is upset. Even with small light on the picture from a 4k movie is outstanding ,for what I Paid (1050.)On sale.I have been a Epson fan for years ,but when picture quality is on the rise from China companies with lower cost and full of features ,as the Mars Pro has it's a no brainer why Epson is wallowing in muddy spec sheets .

the flux in lumens from the projector (source) when divided by the screen area in square meters turns into lux, i.e. surface illumination (reflected light). Which are measured by household lux meters.

You don't understand at all what you are writing. Once again - all the marketing departments of projector manufacturers are pure scammers. They show pictures in advertising to naive consumers that can never be created in such real conditions even with a projector with a luminous flux of 10,000 lumens - find me one with a high-quality picture in everything else, and even with a real resolution of 4k with minimal response of screen matrices (at least 3 pieces to avoid flickering from the wheel on 1xDLP) and an on/off contrast of 2000:1. Because already at 3 sq.m (a banal 106" 16:9 screen), at best there remains 3000 lux (3000 lumens per 1 sq.m of screen surface). When the lighting in the room gives at least 10 lux (and in reality as shown in advertising there will be much more) reflective light from the screen, the contrast immediately drops below 300: 1. This is a shameful contrast. And it is unlikely that anyone in their right mind would want to play, watch movies, TV series or anything else with such a contrast.

If you want a high-quality, high-contrast picture in normal lighting or slightly darkened conditions, buy an AMOLED TV. Even a regular IPS TV will be an order of magnitude better in terms of black level and real contrast in a lit room. But the price of a 100"+ TV (and often also its dimensions) excludes the widespread use of such solutions.

Until cheap AMOLED TVs appear that roll up into a tube, like projector screens. Especially in countries where there are no huge houses, like in the USA, where you can safely dedicate a separate room or an entire basement under the house to a well-made studio.

And in fact, this is entertainment for naive youth. As you get older, you no longer want to watch anything - all the films and TV series are stupid. And the games are clearly not for older people.

Quote from: NikoB on February 20, 2024, 16:47:53And the math is correct.

yeah totally, when you have lux on one side and lumens on the other, one unit is related to area, the other is not
i think they teach it in school, to not mess up units in one equation
but in nbc comments... nothing surprises me

Here's how Epson marketers lie (for example):
mediaserver.goepson.com/ImConvServlet/imconv/a0d7235c605c31df43fde1549901a82d1e9c3304/original?assetDescr=epiqvision_ls800_bg_cutting-edge.jpg
Or from Viewsonic:
i.kinja-img.com/image/upload/c_fit,q_60,w_1315/fd574cc0622d94257be1330165d33f6e.jpg

And here's what it looks like in reality:
cdn.mos.cms.futurecdn.net/tRaUoDwmMR57528A2iNrhn.jpg

Do you want a picture like this when lit? Maybe you shouldn't buy a projector, but rather buy an AMOLED TV? What, is it very expensive for such a diagonal? ))) But whose problem is this, other than the buyer, who already clearly understands what he is dealing with in reality?

Therefore, all this fuss with the maximum brightness level on projectors is, in general, intended for illiterate idiot buyers who have succumbed to fake marketing photos, in which scoundrel marketers from projector manufacturing companies paint blissful pictures of excellent contrast on a regular white matte screen with bright lighting in the room. In principle, this is pure fraud and should be officially punished (at the level of the government consumer protection watchdog) like any deliberately fraudulent advertising on TV and in the press. A couple of fines of 1-5% of annual revenue and everything will immediately improve. I guarantee.

Quote from: lmao on February 20, 2024, 12:41:26math is wrong, lux are not lumens

As a longtime owner of cinema projectors, I am well aware of the difference between lux and lumens. And the math is correct.

Any projector using a matte white screen with a reflectance of 1 is unable to produce a decent level of contrast (minimum 500:1) in bright rooms, with illumination (indirect light) of at least 10 lux. This requires a luminosity of at least 5000 lux. What no projector in the world can provide.

In illuminated rooms, this can only be achieved on special "black" screens with a special surface structure, which does not have very good viewing angles, and such screens (with a large diagonal) cost like good cinema projectors. Those. are inaccessible to the mass buyer, just like decent cinema projectors with real 3 x 4k panels.

I have been well versed in this topic for over 10 years, at an expert level.

Quote from: NikoB on February 19, 2024, 23:38:33typical ambient level - 10lux+, as minimum. 1800/10 = 180:1. Typical contrast in 100% dark room - 2000:1+.

math is wrong, lux are not lumens
but any projector below 2000 is for dark rooms anyway so it's not a revelation

typical ambient level - 10lux+, as minimum. 1800/10 = 180:1. Typical contrast in 100% dark room - 2000:1+.

Quote from: NikoB on February 19, 2024, 20:33:59and not about peak brightness, which no one needs

black point = ambient light level
white point = max brightness level
contrast = white point : black point

brightness is contrast, everyone needs it

Buyers are much more important about the actual level of contrast, and not about peak brightness, which no one needs. No projectors can be used with a white matte screen without 100% darkness in the room. The contrast level (on/off) immediately drops tens, hundreds of times at the slightest illumination from light sources.

Preparing the room to suppress reflection is the second key task of the projector owner. This directly affects ANSI contrast, which is already several times worse than on/off contrast compared to TV screens.

So Epson should start with this. Do not publish false contrast in the description of your projectors, but write real on/off contrast when working with a white matte screen in a 100% darkened room with suppression of reflections in the screen area.

Their scams are 20000:1, 30000:1, 50000:1, etc. have nothing to do with the real on/off contrast, which is an order of magnitude worse on Epson projectors with transmission matrices and several times worse with reflection matrices.

What do owners miss most when they want to watch movies in complete darkness on cheap projectors?

Yes, just the opportunity to reduce the brightness significantly. Because more than 150 lux is not needed for a matte white screen with a reflectance of 1.0 and in complete darkness. And most often, reducing the brightness to 450-700 lumens is not possible on typical screens of 3-4 sq.m.

Thirdly, there are problems with noise level declarations (Epson's figures are again deliberately underestimated, compared to real ones even in "quiet" modes).

Well, the key problem, especially with cheap projectors, is the lack of lens shift over a large range vertically and horizontally (simultaneously), which leads to big problems with installations in difficult conditions.

Who can satisfy mass projectors? Yes, only unassuming teenagers who don't care about real contrast and for some reason want to play on the big screen with a huge input lag.

I have a hard time imagining this target audience. But I know very well the cinema audience watching films only in a 100% darkened room with preparation against reflections - they do not need 3000 or even 1800 lumens. Only provided that the projector matrices have native 4K with high-quality glass lenses. But such models cost as much as cars. And not accessible to the majority of the world's population.

High-quality cinema models, especially 4K, are still exclusive, expensive equipment, available to no more than 1-2% of the population on the planet.