Today's Projectors: Overstated Lumens?

[basspig]

I've been shopping for a DCI 4K projector for a while now, and Sony's VPL-VW600ES is looking like a possibility, mainly because it can go tall enough with the limited throw distance in my theater.

The problem is the calculation at Projector Central shows that for the same picture height, the Sony would have about half the foot lamberts of my existing InFocus IN82.

I also noticed the bulb wattage in the Sony is about half that of the InFocus. Hmmm.. but Sony claims 1700 lumens, vs InFocus' claim of 1500 lumens. If the Sony is brighter, then why is the foot lamberts so much lower for the same picture height? In fact, the calculated lumens correlates with the lamp wattage quite closely. So why isn't the Sony rated at something like 700 lumens, since it's bulb is lower in power and the calculation shows it to be only 18 FL vs 34 for the IN82?

This matter is a real sticking point. Currently, my IN82 is much closer to the screen than 16.6'. At present, the calculation is 59 FL because the picture height is much less than my screen height due to room architectural obstructions. I find the current brightness to be adequate (it's about the same as a LCD panel at 50% backlight brightness, according to my lux meter). This has caused me to believe that to fill my 154" screen with adequately bright images, I need about 5,000 lumens.

From 12' 4", the Sony projector will fill the screen height and it's DCI resolution will get me 114" wide of the 144" of screen, leaving me with 15" of dead space on either side. Much better than my current coverage, but if it's going to be dim, that won't be very useful.

Here's a walkthrow of the space, to give an idea of the screen and projector location (behind the support column).

 

[sawzalot]

Very interesting as BMX has pointed out these manafacturers have found a way to bait the consumer with inaccurate data by boasting more lumens yet delivering a lesser quality pq with a brightness equal to what we already have and or less! Now I am just picking up on all this and have so much more to learn but honestly it really takes input from someone with the up most experience because it becomes fatiguing trying to read all the info . I hope you keep this thread going as I need more info as well.

 

[BMXTRIX]

Let's start by examining your screen to determine the actual size you are looking at.

It appears that you have a 144" wide 2.35 screen.

If you aren't using an anamorphic lens, then any projector you purchase for home theater will be in the 16:9 aspect ratio, and to fill it edge to edge will have significant overspray of unused light/image above and below your screen.

So, you will actually have a 144" x 81" image size you will have, regardless of what height your screen is if you aren't using an anamorphic lens.

That works out to a 165" diagonal, which is FAR larger than the typical home theater screen (92" to 133" diagonal).

But, for lumens measured in square footage, the math is pretty simple: 144" times 81" is 11664 square inches, which is 81 square feet of screen space to fill.

I would shoot for 15 real world lumens per square foot as a minimum requirement, which means you need no less than 1,215 color calibrated lumens on screen for acceptable results.

COLOR CALIBRATED LUMENS!

Color calibrated lumens have really been brought up a lot lately because DLP doesn't play by the same rules that LCD and LCoS must play by with this. DLP can introduce a clear segment into their color wheel which artificially boosts brightness at the cost of color. This makes the projector brighter for white fields, but not for colors, and actually cuts the amount of color light output which is possible. Typically by as much as 66%. The Optoma HD25LV, by example, claiming 3,000 lumens, actually only delivers around 1,100 or so color calibrated lumens. Nearly a 66% drop in brightness when watching video material.

This is why reviews matter and getting good measurements in reviews matters and why color wheel speeds and segments for DLP matter a great deal. The IN82 you have measured out to a maximum light output of about 1,300 lumens in its brightest usable mode. When calibrated down to a normal screen size, it only had about 680 real lumens. That's remarkably close to the claimed 1,500 lumens it reports. It likely is using a 6x color wheel based upon the price and when it was released.

Sony is using a 265 watt lamp, and likely isn't getting a lot more light from it than what you already have, but in testing it delivered over 1,300 lumens. About the same as the IN82. So, you should expect very similar results, from a new lamp and with the projector on full power. Realistically, neither are suited for the size screen you have except when the lamp is new, and when it's on full power. But, through the use of a low gain screen (1.3-1.5 gain) you should actually be able to establish good lumen numbers for standard viewing at the size you are working with.

PROJECTOR CENTRAL'S CALCULATOR: The PC calculator is a tool that isn't often used properly. It's a reference, but isn't a gold standard for image size or brightness. I've caught several calculator issues for size as well. What you need to do is go back to the reviews, the real math. Look at what the measurements were for a projector, for any projector, and decide if it is enough for the screen size you are using.

I use the W1070 which delivers over 1,200 color correct lumens. I use it with a 1.3 gain 161" screen, and this is what it looks like in a room that is less ideal than yours is (see attached).

The Sony projectors are fairly bright, but they are meant for 16:9 image sizes of about 92" to 133". When you push the size, you want to add some gain. You want to be sure to mount the projector towards the front of the available zoom range it has to increase light output as much as possible. You also want to understand that the Projector Central calculator from 8 years ago was not setup the same way it is today. Today's calculator does not work from the manufacturer claims and derates the output from a projector by a certain amount.

Do the math if you question it.
Baseline: 96"x51" screen - 34 square feet - neutral gain screen (1.0)
PROJECTOR CENTRAL - SONY - FRONT OF ZOOM RANGE
The claim is 25 lumens per square foot.
25 times 34 = 850 lumens from the projector.
Projector Central derated the claimed lumens by 50%, even though the review says it can deliver over 50% more light output than that.

PROJECTOR CENTRAL - InFocus - IN82 - FRONT OF ZOOM RANGE (36 square foot screen @ 96" width)
The claim is 42 lumens per square foot.
42 times 36 = 1512 lumens from the projector.
Projector Central did not derate the projector at all. It is using the actual numbers supplied by the manufacturer instead of a middle of the road, middle of the class, measured rating from the projector.

The IN82 calculations are MUCH less honest than what the Sony calculations are.

I'm not sure there are any 4K projectors on the market which can fill a screen the size of what you have without going to a much more expensive class of projector and do it really well for the lift of the lamp. But, with a positive gain screen and a regiment of replacing the lamps every 1,000 hours or so, you may get results you can live with.

This is all a game of balance for projector manufacturers and if you fall outside the bounds of 'standard', then you will pay for that. This is the cost associated with such a large screen. But, you are getting hooked on the lie of the calculator, which you shouldn't let yourself do. The Sony can be brighter than the calculator shows, and the InFocus is a lot less bright than claimed.

 

[basspig]

I have suspected that something is up with the projector calculator, though I downloaded a spreadsheet from another source and the numbers agree with that one too.

When I visit other home theaters, the picture is dim and takes my eyes time to adjust to. Mine is the same brightness as my LCD display. My lux meter shows about 60-78 lux off the screen. Some folks have said it hurts their eyes a bit when transitioning from a dark to a daylight scene. But I most often use my projection system to show clients my cinematographic work. Now that I'm shooting and editing in DCI 4K, I need a DCI 4K projector to properly show it. My only DCI 4K display right now is the 'client' monitor, which is a 31" LG LED display.

The VW600ES claims to have 4096 pixel horizontal, suggesting it's a 17:9 DCI projector, same aspect as my client monitor. Filling a 60" picture height, the calculator says the picture is 114" wide. That leaves me with 15" dead zones on left and right of my screen. A lot better than what I have now.. I think my IN82 from 13' fills about 55% of the area of this screen, and being only 16:9, it leaves about 1/4 of the screen on either side, dark.

What concerns me is the lower wattage of the lamps on the newer projectors. I don't see how a lower wattage bulb of the same tech can produce the same light as a lamp of almost twice the power.

BTW, my screen material is Seymour-AV Center Stage XD. It has a gain of about 1 and is an AT screen. The main speakers are behind the screen.

BMXTRIX, from that screen shot, it looks like you're using a retro-reflective screen. The falloff at the upper half of the image is quite pronounced.

I know that Sony makes good stuff (I own many of the Cine Alta cinema cameras and shoot with them almost daily) but I question the low power rating of the lamp. Since Lcos is similar to DLP in that it's a reflective mirror chip, I would expect the light levels to be similar. The fact that the light passes through a beam splitter also reduces light output. It may be debatable if the color wheel in DLP kills as much light though.

One thing is for sure: the prices of these projectors are out of this world and have been for a long time, while UHD TVs are becoming cheaper than their HD predecessors already. Rumor has it that Sony is racketeering to keep the price high, so as to keep DCI 4K out of the consumer market and draw bigger crowds to the commercial theaters. DCI 4K remains in the five figures and up range still.

For me, an ideal projector would support DCI 4K, REC.2020 and HDR. Maybe use LASER light sources. I was watching what happens with RED's RedRay, but it appears to have been shelved. Meanwhile, I am literally dying to see 4K on my screen before I go completely blind.

 

[BMXTRIX]

The IN82 only uses a 300 watt lamp. The Sony uses a 265 watt lamp. That's about a 10 percent difference in baseline wattage, which is extremely easy to make up by using better optics within the lens. If you know photography, then you know that a larger lens or a better lens can have significant impact on light exposure. This is the same way with projection lenses.

LCoS is a cross between LCD and DLP - it uses 3 chips, always, just like LCD projectors do, but it passes the light through an LCD panel twice which significantly improves native contrast and improves inter-pixel gap (screen door effect).

For what it's worth, I think it was just that stadium scene. I'm using a Draper screen with 1.3 gain. Nothing retroreflective. Just shot on my iPhone quickly, and hand held. I was not looking to show the performance of much, but to give an example of the W1070 on a 161" screen, and I have some shots with some lights on which look poor, but still leave a usable image.

DLP doesn't have any specifically good or bad light levels. It depends on the color wheels which are used, and more recently DLP manufacturers have been extremely deceptive in their practices and use of 2x color wheels with larger clear segments.

I could also get into 4K and why it costs so much.

Sony is making a killing. They are basically the ONLY 4K game in town. DLP has nothing at the consumer level. They are sitting on their heels with nothing and look like tools for completely failing to respond to consumer and business desire for 4K projectors. Epson and JVC haven't been able to get there, but both are trying and have interpolated 4K images through similar techniques, but both use LCoS to deliver that virtual 4K image. Epson hasn't delivered with LCD yet.

So, your choice is Sony... Or nobody. Yeah, Sony isn't lowering prices to compete when they have nobody to compete against yet.

Not sure when solid state light engines will show up in color balanced projectors and can deliver 2,000+ color calibrated lumens, or handle REC2020, or much else that you are looking for. They have a ways to go, and the nearly complete lack of 4K projectors or chips outside the Sony models is a real hindrance to consumers.

Hoping for more 4K models soon, but it's not like BenQ can magically develop a 4K DLP chip. Need more competition.

Still, I saw the 500ES. It was spectacular on the 120" Carada screen it was projecting onto.

 

[basspig]

I can relate to the single-sourcing issue with both the projectors themselves as well as the DLP chips. Probably similar with Lcos.

Thanks for explaining the general Lcos operation. Yes, larger lenses have lower F-stop numbers. I shoot night scenes with an F/.95 35mm cine prime lens and it's amazing how it turns night into day, compared to my T/2.2 cine prime that's useless at the same 500 ISO setting. But the faster the lens, the shallower the depth of field, and I would imagine you need a slightly parabolic screen to keep the focus from center to edge, just like a CRT with a curved face. Flat CRT screens require dynamic focus, but there is no equivalent in optics. Somewhere there's a balance.

I've looked on eBay, but no one is yet selling a used 4K projector. I see some leftover discontinued VW600ES models, nicely reduced in price.

My friend who sells and designs high end home theaters has a used Sony SRX series that cost six figures and was willing to sell it to me for $10K, but it's huge and weighs 230lbs and needs 240 VAC service, not to mention the fans are as loud as a Hoover vacuum. It needs two new xenon lamps which will cost a few grand each, so I decided to wait and see what else comes down the pike. 5000 lumens would have been nice though, but would need lots more than 2000 contrast ratio to make black levels on a smaller screen.

For HDR, I'd probably need 50,000 lumens to make it work, along with 12-bit color. My cameras shoot 16-bit color internally, and I get 12-bit raw at 12Gb/sec. The master footage can exceed 14 f-stops of dynamic range and the color gamut exceeds Adobe RGB by a large margin, aligning closely with the ACES triangle on the chromaticity chart. Finding display devices that can show this gamut has been an exercise in futility so far. The IN82 is particularly lackluster in the reds, probably because of the UHP lamp having less energy in the red end of the spectrum than towards green. It's always been a challenge to get good reds out of it. The LG display does a respectable job of color and the brightness is almost good enough, but it's only 31". I use that for the client preview. For 1080 work, we use the IN82 on the screen so the clients can watch their concert in comfort and with top notch audio. 4K sits on the horizon like a mirage at present. Is it really there, or much farther off than it appears?

 

[BMXTRIX]

4K is farther off than it appears. At least, that's the way it appears to me.

DLP is a huge sticking point in this. TI has sat on their collective butts for the last few years since the demise of the rear projection DLP setup. The massive profits of selling people a 70" 12" deep TV for their home is gone. Replaced by actual flat panels.

So, Dark Chip 3 is still the technology in use, and 4K DLP is used in theaters and in high dollar commercial DLP setups. There are some solid state engines running 4K commercial setups, and they are pricy, and they are bright - and getting brighter. But, the consumer UHD chip still hasn't come to market. I've heard rumors that TI was under contract to NOT produce a consumer UHD chip until the cinemas had them for at least three years. This rumor has been running for about 3 years now, so if TI is going to deliver for the home and business market, I think it needs to happen in the next year. It should have been there already.

From all appearances, Epson can't deliver UHD in a LCD panel. That's why they've gone to LCoS along with JVC. Both companies are pushing their LCoS technologies to deliver an excellent image, but it's not native 4K. Still, they are getting the processing in place, they are working out the bugs, so when we see true 4K from them, it likely will be a pretty good product.

Still, there is no pipeline for carrying the video. 18Gbs for HDMI 2.0, and something like 20.6 for DisplayPort. UHD with 4:4:4 12-bit color is well above that data rate with 60Hz video. It may be able to do it with 30Hz or 24Hz video though.

As well, manufacturers still have to address HDCP 2.2, actually get working cables to support the full 18Gbs backbone. Actually get scaling which doesn't destroy the image in the process, etc., etc., etc.

People forget that when Blu-ray came about, the pipeline for 1080p/24, the video processing, the ability to handle new HD audio codecs, etc. was beyond what many computers could handle. There weren't system on a chip setups which could handle that data rate. The entire structure needed to be built up and a great number of televisions were still struggling with 1080p in general.

Now, a cheap TV from WalMart has no problem with 1080p and it's commonplace to see as a standard.

That's taken almost a decade from when the first BD players hit the market to now, and the jump from 720p (or 1080i) to 1080p was only a doubling of pixel density, vs. the four fold increase which UHD is giving us.

I would expect 3-5 years to really be a pretty good point for UHD. Until then, it will be buggy and it will be pricey.

 

[basspig]

If there is some sort of contract NOT to produce, that's unfortunate. We need more players in the market to create marketing pressure.

Displayport 1.2 is a good solution for the inputs. My 4K ideal projector would have at least one DP 1.2 port for the computer NLE. HDMI for the BD player. Maybe a host of other legacy options.

UHD is no solution. I want something that will do native 2.35:1 without zooming and overscanning (which loses resolution and light). DCI 4K would be an acceptable compromise, if the price is under $7K. That will fill all but the last 30" of screen in the horizontal dimension.

Maybe in ten years this will get sorted out, but I hope it's not going to be UHD only. Although in ten years I may not be alive to enjoy it!

 

[BMXTRIX]

UHD is by far and away the most likely product we will see. 3840x2160 isn't far off from the 4096 which 4K has for width. So much more is based around consumer usage rather than professional use, so time will tell, but I know that a number of companies have told me already that their implementation of 4K will be UHD, not DCI 4K.

I know it would bug the heck out of you, but I just don't care that much. There are millions of 16:9 projector screens in homes already. Having to replace them would piss off a lot of people for no reason. But, a DCI 4K projector which can do a clean mask down to 16:9 would be alright by me as well.

I'm more interested in just seeing better product come to the market.

 

[basspig]

As a 4K shooter, I guess I'm stuck in the six figure pro projector category.

My screen is 2.35:1 and was built that way in anticipation of 2560x1080 projection, which never took off. I think one company made such a projector, priced over $30K.

For me, it will have to be a Sony SRX series, at some point. Heavy, energy hungry, and noisy.