Sorry for an "old question"..

I have a new Panasonic PT-AE3000U projecting on a 80" wide screen using Cinema1 mode (in a room w/o any lights)

I use a test DVD which gives me light levels (whole fields) from 0% to 109%.

Using a standard light meter at the screen, I get:
0%: 0.44 lux
100%: 98 lux
(109%: 127 lux)

Thus would my contrast ratio be:
98/0.44= 223
or
127/0.44=289
(not sure which number to use; 100% or 109%?)

As far as I understand this is the full on/off ratio, but it is way too low. According to the specifications, it is supposed to be 60,000.

It is even much lower than the ANSI ratio measured in the reviews (e.g. 446 http://www.projectorcentral.com/panasonic_ae3000_projector_review.htm).

What am I doing wrong?


BRIGHTNESS Comment:
The maximum light output, 127 lux, was in Eco mode. It is 10% higher in Normal mode: 140 lux. Thus, with my 80" wide screen (25 sq.ft) this is equivalent to:

140*25/10.76= 325 lumen (Cinema 1) .

This is about 21% lower than measured in reviews:
385 lumen (http://www.projectorcentral.com/panasonic_ae3000_projector_review.htm)
or
402 lumen (http://www.projectorreviews.com/panasonic/pt-ae3000u/performance.php)

Operator error. Your 0 IRE level measurement is way too high. Go to a 2006 thread by Lovingdvd titled using your CA813 light meter to measure your front projector. post 1. follow the procedures.

Sorry to disapoint you, but the 60,000:1 contrast claim by Panasonic is for the unusable 'Dynamic' mode. For the Cinema 1 mode IIRC Cine4home measured around 6,000:1 depending on zoom (less zoom equals higer CR, but lower brightness.

In practice you may find that even using Dynamic mode you still won't measure 60,000:1 (except in some kind of blackout test booth perhaps). Also you'll need to push the contrast control to maximum (only during the 100IRE test) which wouldn't be the correct setting for accurate greyscale.

Operator error. Your 0 IRE level measurement is way too high. Go to a 2006 thread by Lovingdvd titled using your CA813 light meter to measure your front projector. post 1. follow the procedures.

I am using this BD DVD: http://www.avsforum.com/avs-vb/showthread.php?t=948496

Would 100% or 109% be equal to 100 IRE? What is the relationship?

I am using this BD DVD: http://www.avsforum.com/avs-vb/showthread.php?t=948496

Would 100% or 109% be equal to 100 IRE? What is the relationship?

I use this calibration disc myself and my Lumagen shows the current IRE levels in certain modes: It shows 100% as 100 IRE, the 109% is for 'headroom' AFAIK, you would probably measure a greyscale short of red at 109% as PJs tend to 'run out' of red at higher IREs (hence why you sometimes need to lower the main contrast to get the greyscale flat).

Hope that helps, hope you didn't mind my earlier post, but it does annoy me how manufacturers twist their CR claims in an attempt to best their competitors. In practice my new HD350 has much better blacks and brighter whites with it's supposedly inferior CR of 30,000:1 (if you go by the specs/claimed figures) than my old AE3000 had.

Using a standard light meter at the screen

What is "a standard light meter"? Illuminance meters are generally graded by their f1' fit to the CIE V(lambda) function, but f1' of 10%, for example, does not preclude errors much greater than 10% when measuring an additive color (3 narrow bands) projection beam. So your absolute lux values can be off. Interestingly, this could also affect your contrast measurement since the projector's black output can be spectrally very different from its white output. (It's not equally effective at blocking different wavelengths.)

Still, you've got too huge a discrepancy to explain this way. What is the specified lower limit of your illuminance meter? What black lux value does it read when you cover exactly half the front of the projector lens? (Measure at the center of the screen.)

I am using the CA813 light meter. I followed the instruction here: http://www.avsforum.com/avs-vb/showthread.php?t=755705&highlight=ca813+light+meter+measure+front+projector
as suggested and repeated my measurements by placing the sensor 12' away from the lens (and using a Tripod). Again, I am using Cinema1, lamp in Eco mode, BD-DVD player is Pioneer BDP-51FD (connected to HDMI) and DVD disks are the ones from the AVS forum (see above).

0% field ("black"): 129.8 lux (no typo- it is really bright when "Black"!)
100% field: 31.1 klux
109% field: 40.1 klux

Thus, best case ON/OFF CR=40100/129.8=309
This is very poor

Second I connected the projector to my Scientific Atlanta Cable Box HDMI output and turned the Box off (that is the only way I could get it to be "black");

"Black": 51.8 lux
I can not get the box to generate a white field; but I assume the same level as above as the meter was not moved: 40.1 klux
CR= 40100/51.8=774
Still very poor

Third, I connected the projector to the VGA output of a laptop computer and used UDpixel software to generate white and black fields:

Black: 6.68 lux
white: 45.2 klux
CR=45200/6.68=6,766
More reasonable (but not great), and similar to that obtained by Cinema4home according to the post above (but still a far cry from the advertised 60,000)

Because the results were so poor when using the HDMI input, I hooked up a second computer with DVI output. Using a DVI-to-HDMI adapter, I tested the second computer using UDPixel:
Black: 6.53 lux
white: 40.3 klux
CR=40300/6.53=6,172
This is close to the previous measurement, and again reasonable (but not great)

However, why are the measurements so poor when using the BD-DVD player or the HD (DVR) Cable Box??
Are the signal levels not matching somehow?
How can I troubleshoot / Fix?

Why are the measurements so poor when using the BD-DVD player and the HD (DVR) Cable Box?? Are the signal levels not matching somehow?

Do you have the HDMI setting on the AE3000 to standard or expand? Also your BluRay player should be set to standard or 'video' (as oppossed to 'PC') to match, plus your brightness control may need to be at a different setting according to input. IIRC I had my BluRay player memory set to brightness at 0 or maybe -1, but my DVD player was lower like -2 or -3. It doesn't take much adjustment to the brightness level to lose your contrast ratio.

The results using the VGA input (and presumably still in Cinema 1 mode?) are about as good as you will get depending on your throw. You could try zooming right back (smallest image incase we differ on zooming terms ;)) and see if that measures a better CR as measured by Cine4home.

BTW you can use the waveform monitor to 'see' what levels the AE3000 is measuring. If the WM doesn't show your black test pattern at '0' then you need to lower the brightness control until the WM shows it at exactly '0'. I used to use the single line mode for this. Also, have you adjusted any of the advanced RGB controls as moving the RGB brightness up from '0' will reduce contrast also.

BTW, have you tried measuring the Dynamic mode?

Do you have the HDMI setting on the AE3000 to standard or expand? Also your BluRay player should be set to standard or 'video' (as oppossed to 'PC') to match, plus your brightness control may need to be at a different setting according to input. IIRC I had my BluRay player memory set to brightness at 0 or maybe -1, but my DVD player was lower like -2 or -3. It doesn't take much adjustment to the brightness level to lose your contrast ratio.


BTW you can use the waveform monitor to 'see' what levels the AE3000 is measuring. If the WM doesn't show your black test pattern at '0' then you need to lower the brightness control until the WM shows it at exactly '0'. I used to use the single line mode for this. Also, have you adjusted any of the advanced RGB controls as moving the RGB brightness up from '0' will reduce contrast also.

BTW, have you tried measuring the Dynamic mode?

Indeed, somehow it had been changed to expand. I set it back and used the WM to check. At projector factory defaults (brightness= contrast=0) DVD 0% and 100% fields landed exactly at 0% & 100% on the WM! (It made no difference if I changed the BR-DVD settings from LCD to Projector etc...).


Interestingly, when using WM (linescan) and checking the levels from the Cable Box, I needed to adjust brightness and contrast to +11 and -11 respectively in order to set the lowest and highest signals to 0 and 100%! I suspect that the majority of users never check this! Thanks for the reminder about the WM!


BTW, when I switch between the BR-DVD and the Cable Box (using the same HDMI input), the projector remembers the Brightness setting for each device.
Amazing... How is that possible? Does the projector read some device code and stores the settings for each device code? How many can it automatically save in this way?


I repeated the measurements using the DVD player and lamp in Normal.

Cinema1:
0%: 7.03 lux
100%: 38.6 klux
109%: 50.3 klux

=> CR= 38,600/7.03=5,491 which is slightly lower than Cinema4home
or if using 109%
=> CR= 50,300/7.03=7,155 which is better than Cinema4home
(Note that my previous computer measurements would be comparable to this, as the computer white field is probably comparable to the 109% DVD field)

Dynamic:
0%: 1.45 lux !!
100%: 172.5 klux
109%: 196.9 klux

=> CR (100%)=172500/1.45= 118,966 !!! :D

This is incredible?? With Dynamic Mode, I had expected higher light output at both 0% and 100%. However, only 100% increased and 0% actually decreased!!

Sorry, I have not followed the AE3000 threads, but are there some internal filters or something that is removed when using Dynamic Mode? Maybe this causes light scattering in Cinema1 mode and thus increases the light at 0% (vs Dynamic mode).

How about Normal mode (not measured yet as the batteries in the light meter died :o)?

If this is the case, maybe it would be better to get use Dynamic Mode with an external filter instead (and of course recalibrate the projector)?

If this is the case, maybe it would be better to get use Dynamic Mode with an external filter instead (and of course recalibrate the projector)?

I found on my original (damaged) AE1000 that the iris closes further in Dynamic mode, so this accounts for the improved black level (I ran it with the covers off as it was wrecked anyway). However in Dynamic mode the internal colour filter is not in place (it halves the light output at least, maybe more), so the iris must close a lot further to make up this difference. The iris doesn't open any further with 100 IRE (even if there are black bars top and bottom like with 2.35:1 films) in either mode as I also found during this testing. I have no reason to believe that the AE2000 & AE3000 are any different given my experience with them and your measurements. However there was some mention of the AE3000 being able to control the lamp brightness as well which the older models didn't do, so this may also cause a boost in Dynamic at 100 IRE, but that's purely conjecture on my part.

This is partly what started my search for a suitable external filter to allow me to use Dynamic mode and still calibrate to D65. If Panasonic allowed you to choose the iris modes within the PJ's menu (rather than them being 'hidden' and 'tied' to particular modes), then you could use the more aggresive setting from Dynamic mode and try it with Colour 1 for example. Unfortunately this isn't possible even in the serivce menu. :(

Normal mode also doesn't use the internal filter (which is why it is brighter) and the iris mode isn't so aggresive as Dynamic.

Also measured Normal Mode now (and lamp in Normal);
0%: 15.1 lux
100%: 84.1 klux
109% 104.6 klux

=> CR(100%)=5,569
Similar to Cinema 1 Mode

=> CR(100%)=5,569
Similar to Cinema 1 Mode

That is what I seem to recall; you get a brighter image (due the internal filter being out of the light path), but the black level is equally higher. The other issue I found was that the 90 and 100 IRE greyscale was further out than in Cinema 1 mode (on my particular example). The only way to bring it closer was to reduce the main contrast control, below '0', which meant that I lost some brightness, reducing CR further. If you're not fussed about a perfect greyscale, then Normal can be quite acceptable, so you can just get on and enjoy the picture. :) Sometimes I think we get too hung up on specifications and measurements, hence why I've deceided not to bother calibrating my new HD350 even though the hours are now reaching the 100 hours point that I said I'd wait to before doing it....If I'm enjoying the picture, who cares what the measurements are (especially if the sensor is questionable anyway an I1-LT in my case).

I daren't go into the calibration sub forum now after that confession. ;)

Home Theater got 2843:1 in their March 2009 issue. If this fraudulent 60,000:1 "Dynamic Contrast Ratio" rating had anything to do with you making the decision to buy that projector then go to www.ftc.gov and file a complaint. It doesn't matter if you're pleased with the projector or not. What matters is that the manufacturer (and the retailer that sold it to you) used a fraudulent statement to induce you to make that purchase. It's against the law. If enough people would get off their behinds and complain about this the FTC would force manufacturers to adopt a measurement standard that makes sense...or pay hefty fines. The process works people, don't tolerate being lied to!!

Unfortunately, it's not fraudulent, they don't say ANSI contrast they say full on/off contrast. If they can measure it to 60,000:1 then they didn't make a false statement. It's a completely useless way to compare devices but it's not false.

I'm betting the unit can't do it and the manufacturer knows it. I think the number's just there to sell the projector. If that projector can't produce that level of performance under "normal" testing parameters, the 60,000:1 statement is used in product advertising as an inducement to cause the customer to purchase the projector, and if the projector's actual ANSI performance specifications are so much lower as to cause a potential consumer to change their purchasing behavior, then by the definition of Deceptive Acts and Practices in the FTC Policy Statement on Deception, it's false advertising under Section 12 and possibly Section 5 of the Federal Trade Act.

I'm betting the unit can't do it and the manufacturer knows it. I think the number's just there to sell the projector. If that projector can't produce that level of performance under "normal" testing parameters, the 60,000:1 statement is used in product advertising as an inducement to cause the customer to purchase the projector, and if the projector's actual ANSI performance specifications are so much lower as to cause a potential consumer to change their purchasing behavior, then by the definition of Deceptive Acts and Practices in the FTC Policy Statement on Deception, it's false advertising under Section 12 and possibly Section 5 of the Federal Trade Act.ANSI CR measures something totally different than on/off CR (they indicate different things as ANSI CR is basically about washout effect and on/off CR is about the raised black floor effect) and what do you mean by "normal" testing parameters? On/off CR is a normal testing procedure (although there seems to be a lot of ignorance about it) and I think the projector can do somewhere in the range of 40k:1+ in Dynamic mode from what I can see. They don't say it is going to have standard color balance at that max CR. While I do think the spec would make many people who don't understand CR think it can do something different than it can, I highly doubt you could win a case on this. Especially if Panasonic can just take one, put it in Dynamic mode with the DI enabled, and measure somewhere close to that spec for on/off CR.

--Darin

They can do it, and sometimes even independent tests show higher numbers. This is because the full on/off measures the brightest white capable with the iris full open and the darkest black with the iris closed. All manufactures show this number, I have never seen an ANSI number listed in the manufacturer supplied specs from any manufacturer in this low end price range. The specs clearly say full on/off contrast, it's not deceptive just because the consumer does not know what that means. If one manufacturer would break ranks and list ANSI contrast, the number would be much lower and they would be at an unfair disadvantage.

I've been scanning tests in every publication I can get my hands on for over two years and other than a couple of newer LED backlighting flat panel sets that have been tested of recent, I've yet to see any TV even get close to it's advertised dynamic figure so I'd love to see an example....in a nationally distributed publication...especially on a lower priced priced product.

Article after article, written by recognized and credible sources state the same thing: "Dynamic Contrast Ratio" is a contrived specification developed for advertising purposes.

Section 12 of the FTC Act is pretty clear. Sony, Panasonic, Samsung, and others use this specification to influence consumer behavior. If the set can't duplicate the claim, it's fraudulent advertising...and the reason there's no set standard for measuring contrast ratio on televisions has nothing to do with not being able to regulate it or manage it. That excuse is horse manure.

Not to let the retailers off the hook...Section 12 states "...disseminate or cause to be disseminated..."

As a retailer, I have to compete against products whose performance is deliberately misrepresented to the consumer in order to compensate for being sold in a store with no competent sales staff. As a consumer, I believe I have a right to consistently derived information with which to make a purchase.

A home entertainment system can be the most expensive "appliance" in a consumers home and yet the reality is that a consumer can't trust what the manufacturers are saying about the products. What's wrong with this picture?

For every example you might be able to produce where a product does meet this claim, I'll show you 30 lies....that's pretty much the ratio my research has found.

Even more amazing than the fact that these manufacturers and complicit retailers have been getting away with this for years it that a good number of smaller, performance oriented manufacturers have watched their sales and market share dwindle indirectly as a result and they've done nothing to stop it.

I simply do not understand why responsible people allow this to happen in an industry that should, for all intents and purposes, represent itself with integrity.

Article after article, written by recognized and credible sources state the same thing: "Dynamic Contrast Ratio" is a contrived specification developed for advertising purposes.There has been a lot of misinformation about CR by people who are recognized and considered credible for years. For instance, the ISF organization has been teaching people for a long time that humans can't see more than say 900:1 to 1200:1 and so on/off CR beyond that doesn't matter, but that is based on them not comprehending the subject matter. I talked to one of their teachers and hopefully they have stopped misleading people about that. Another person who teaches courses and used to be with ISF has been misleading his students about on/off CR too. He was wrong about some very simple physics (thinking that having a light colored room would mean lower on/off CR because light from the projector would hit the screen, go around the room and decrease on/off CR) and so thought some things about on/off CR that weren't true.

I would suggest listening to people like Bill Cushman, Greg Rogers, and the Cine4home guys, who have described on dynamic contrast ratio can have a real and positive impact images.

That isn't to say that a dynamic system can't be bad and just be for marketing purposes, but dynamic systems done right can add a lot of positives to the images. Panasonic has one of the better DIs, but that is mostly in the cinema modes that are maybe 6k:1 dynamic. To get to their 60k:1 they really have to push things beyond what I think adds more good than bad, but they can get there. So, there is some gray area I think where the DI helps things up to around 3x-5x the native on/off CR if done well, but beyond that I think they are pushing too much (at least for current projectors).
Section 12 of the FTC Act is pretty clear. Sony, Panasonic, Samsung, and others use this specification to influence consumer behavior.And if they can hit it I don't see how anybody would have a leg to stand on. Using an article from somebody who is supposed to be credible isn't likely to help much, especially if a cross examination shows that this person doesn't really know what they are talking about. It would be pretty easy for Panasonic to show some images with the projector where the DI brought real image quality improvements.

I think it is somewhat unfortunately that CR is complicated enough that it takes quite a bit to understand how different things affect the images (like native on/off CR vs dynamic on/off CR). But I just don't see much of a case here if Panasonic can come close to that spec. They don't claim they have that for native on/off CR and Widescreen Review has some good reviews that include what dynamic on/off CR brings to the table (when done right).

--Darin

Perhaps the position that the manufacturers are lying is too blunt. (Although I believe that is the case) The consensus within this forum, when the question comes up, is that "Dynamic Contrast Ratio" is not a worthy comparitor for the consumer to use when making a purchasing decision. In that light, the use of "Dynamic Contrast Ratio" is misleading, at best, and downright fraudulent as an extreme.

Regardless of which, it obviously has an effect on consumer behavior. If a retailer chooses not to use this term in their own advertising because of the questionable integrity of said claim and the lack of a valid standard for creating the specification in the first place, he puts himself at a competitive disadvantage to those retailers who choose to use "Dynamic Contrast Ratio" in their own advertising.

Given that the manufacturers as a group don't appear interested in establishing such a standard and, in fact, they've been deliberate about avoiding such a standard for the cause of using said misleading advertising, for the consumers sake, it merits scrutiny by the FTC or even possible actions under the Lanham Act.

Whether a TV does 50:1 or 5,000,000:1 doesn't really matter to me. Whatever the manufacturers use should be consistent and relevant and anything less is misleading and suspect to fraudulent advertising claims.

As a retailer who chooses to represent the products we sell on their true performance merits, I'm tired of being told by the Consumer Electronics press that my business model is obsolete and that I need to get into the custom security business. In 10 years Wal Mart and Best Buy will be doing that as well so it makes more sense to me to turn around, dig in my heels, and fight for what I believe in that it does to continue running and hiding, trying to make money on something I don't enjoy doing or dont' care anything about.

The fact that the manufacturers of televisions and Home Theater in a Box products have chosen to be so aloof about how they present their products to the consumer and so deliberate in their avoidance of creating any relevant specification standard for the sake of profit and market share has left the door wide open for this type of scrutiny and I intend to take advantage of it. A little time and pressure is all it takes.

Speaking of twisting numbers,look at the Behringer EP4000.The power is much higher than the outwardly identical EP2500. The power consumption is the same,the weight is the same,they look the same.They went and used a peak power rating which boosts the numbers by over 50%.I have bench tested both amps.

The reference to the Lanham Act in my previous post was related to an "avenue" suggested to me following questions about an article I read recently. Lanham is not relevant here.