JVC 2011-2012 lamp measurement project - Page 4 - AVS Forum
Forum Jump: 
Reply
 
Thread Tools
post #91 of 391 Old 12-07-2011, 08:55 PM
AVS Special Member
 
coderguy's Avatar
 
Join Date: Dec 2006
Posts: 9,953
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 140
Remember these cheap meters have serious problems with even relatively low light accuracy. He probably is getting a bit more light than that, but the meter isn't registering the lower levels correctly in his room. The accuracy the meter's tend to claim isn't the real accuracy you actually get.


Quick and Easy Shelf Mount Method for both one projector or dual stacks

Web Calculator v023 & v025
- Quick Peak at the new upcoming calculator
**Current Projector Calculator** -- http://www.eliteprojectorcalculator.com

Coder's Top Projector Picks of 2012 --http://www.avsforum.com/avs-vb/showthread....

coderguy is offline  
Sponsored Links
Advertisement
 
post #92 of 391 Old 12-07-2011, 09:02 PM - Thread Starter
Advanced Member
 
jim2100's Avatar
 
Join Date: Aug 2011
Posts: 762
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 33
Quote:
Originally Posted by coderguy View Post

Remember these cheap meters have serious problems with even relatively low light accuracy. He probably is getting a bit more light than that, but the meter isn't registering correctly.

The LX1010B specifies accuracy of +/- (5% + 2d). So, for a 20lux reading, the lowest digit is 1 lux, so 5% of 20lux + 2d = 1lux + 2lux = 3lux. Which gives us 20+/-3 lux accuracy.
jim2100 is offline  
post #93 of 391 Old 12-07-2011, 09:04 PM
AVS Special Member
 
coderguy's Avatar
 
Join Date: Dec 2006
Posts: 9,953
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 140
It's surely accurate enough to take lumen readings, but not when the lumens get too low. I don't know never tried a reading that low other than a contrast reading, but I wouldn't trust it.


Quick and Easy Shelf Mount Method for both one projector or dual stacks

Web Calculator v023 & v025
- Quick Peak at the new upcoming calculator
**Current Projector Calculator** -- http://www.eliteprojectorcalculator.com

Coder's Top Projector Picks of 2012 --http://www.avsforum.com/avs-vb/showthread....

coderguy is offline  
post #94 of 391 Old 12-07-2011, 09:52 PM - Thread Starter
Advanced Member
 
jim2100's Avatar
 
Join Date: Aug 2011
Posts: 762
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 33
Quote:
Originally Posted by coderguy View Post

It's surely accurate enough to take lumen readings, but not when the lumens get too low. I don't know never tried a reading that low other than a contrast reading, but I wouldn't trust it.

Well, I trust it to be accurate within 3lux at a reading of 20lux. But the main point is that his old projector appears to be measuring nearly 10x lower than what most people would consider an optimum brightness level. Surely you are not implying that the reading of 20lux is inaccurate by a factor of 10 too low? There is just no way it is off that much. Even a factor of two (40lux vs. 20lux) is very hard to believe.

Unless you have some real evidence of inaccuracy, I trust the spec, which says at 20 lux it is accurate to +/- 3lux.
jim2100 is offline  
post #95 of 391 Old 12-07-2011, 10:20 PM
AVS Special Member
 
coderguy's Avatar
 
Join Date: Dec 2006
Posts: 9,953
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 140
I don't know the real accuracy of a cheap meter, but I do know that they are often not as accurate as they claim as shown by many posts in this forum.


Quick and Easy Shelf Mount Method for both one projector or dual stacks

Web Calculator v023 & v025
- Quick Peak at the new upcoming calculator
**Current Projector Calculator** -- http://www.eliteprojectorcalculator.com

Coder's Top Projector Picks of 2012 --http://www.avsforum.com/avs-vb/showthread....

coderguy is offline  
post #96 of 391 Old 12-07-2011, 11:22 PM - Thread Starter
Advanced Member
 
jim2100's Avatar
 
Join Date: Aug 2011
Posts: 762
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 33
Quote:
Originally Posted by coderguy View Post

I don't know the real accuracy of a cheap meter, but I do know that they are often not as accurate as they claim as shown by many posts in this forum.

Please provide a link to a post or posts that shows convincing evidence that the LX1010B or a similar meter are not as accurate as they are specified to be.
jim2100 is offline  
post #97 of 391 Old 12-08-2011, 12:02 AM
AVS Special Member
 
coderguy's Avatar
 
Join Date: Dec 2006
Posts: 9,953
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 140
That's a lot of work to find all those posts, you can go find them as you are the one conducting the study, they are scattered throughout the calibration threads. I have seen various posts in the calibration threads about it, but no one is hardly using $15 meters in there, so who knows. Like I said, I don't know the accuracy of this meter.

Even if you just go read reviews, you will see some reviews claim 20% drop-offs from closest throw to farthest throws, while others claim 30%+ for the same projector. Not talking about lumens between reviewers, talking about throw modifier conflicts for the same model of projector between reviews.

Is it measuring technique, reflective light, meter error (obviously not all meter error), projector variances (not likely with this much variance), etc...

I don't know what it suggests nor do I have time to figure it out at this very moment, but it suggests something.


Quick and Easy Shelf Mount Method for both one projector or dual stacks

Web Calculator v023 & v025
- Quick Peak at the new upcoming calculator
**Current Projector Calculator** -- http://www.eliteprojectorcalculator.com

Coder's Top Projector Picks of 2012 --http://www.avsforum.com/avs-vb/showthread....

coderguy is offline  
post #98 of 391 Old 12-08-2011, 12:17 AM - Thread Starter
Advanced Member
 
jim2100's Avatar
 
Join Date: Aug 2011
Posts: 762
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 33
Quote:
Originally Posted by coderguy View Post

That's a lot of work to find all those posts,

It is a lot of work to find even one post that you claim provides evidence that the LX1010B meter, or one like it, is not as accurate as it specifies? Really?

I think I will take the specifications from the meter manufacturers over some elusive evidence that only you know of but cannot reference.
jim2100 is offline  
post #99 of 391 Old 12-08-2011, 12:19 AM
AVS Special Member
 
coderguy's Avatar
 
Join Date: Dec 2006
Posts: 9,953
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 140
I just gave evidence. I was just posting for the benefit of accuracy.

Like I said, I don't know how to explain reviewer discrepencies on throw percentages, but I do know that when I myself measured multiple units of the same model, I found no real % variance in the throw modifier for lumens at a given distance between one unit to another, yet the reviews are conflicting here. Hence, if it were 10% on one, I measured 10% on the other, but you go from one reviewer to the next and you'll see 10% and then 20%, it's crazy off.


Quick and Easy Shelf Mount Method for both one projector or dual stacks

Web Calculator v023 & v025
- Quick Peak at the new upcoming calculator
**Current Projector Calculator** -- http://www.eliteprojectorcalculator.com

Coder's Top Projector Picks of 2012 --http://www.avsforum.com/avs-vb/showthread....

coderguy is offline  
post #100 of 391 Old 12-08-2011, 12:32 AM - Thread Starter
Advanced Member
 
jim2100's Avatar
 
Join Date: Aug 2011
Posts: 762
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 33
Quote:
Originally Posted by coderguy View Post

I just gave evidence.

You gave no evidence that the accuracy of the LX1010B meter, or one like it, is worse than the manufacturer's specification.

Basically, you gave a convoluted description of your interpretation of some measurements that seemed inconsistent, then jumped to the conclusion that some meters were not as accurate as claimed. That is not evidence. It is wild conjecture.

It takes persuasive evidence to prove that a manufacturer's specification for their meter is wrong. You have not provided any evidence at all. Your claims are spreading FUD (fear, uncertainty, doubt) without having any substance.

As I said, the accuracy specifications from the meter manufacturers are far more trustworthy than your unsubstantiated conjectures.

If you wish to debate this issue further, please take it to PM, or another thread. If you had linked to actual evidence, I would not have a problem with your posts in this thread. But as long as you are spreading unsubstantiated conjecture, I think it is only cluttering up this thread and causing confusion.
jim2100 is offline  
post #101 of 391 Old 12-08-2011, 12:42 AM
AVS Special Member
 
coderguy's Avatar
 
Join Date: Dec 2006
Posts: 9,953
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 140
Why not just have someone test it at a low lux count and see, I could be wrong, but I know several people tested it at a higher lumen count and found it accurate enough, but where does it lose accuracy. From my understanding, the accuracy ratings you see I think are only for certain spectrums and wavelengths or types of light (around 2800), but the question is if a LUX meter with 0.01 is often only accurate to 0.1 or 0.2, then how accurate is a $15 lux meter with 1.0 resolution, personally I don't know.


Quick and Easy Shelf Mount Method for both one projector or dual stacks

Web Calculator v023 & v025
- Quick Peak at the new upcoming calculator
**Current Projector Calculator** -- http://www.eliteprojectorcalculator.com

Coder's Top Projector Picks of 2012 --http://www.avsforum.com/avs-vb/showthread....

coderguy is offline  
post #102 of 391 Old 12-08-2011, 12:56 AM - Thread Starter
Advanced Member
 
jim2100's Avatar
 
Join Date: Aug 2011
Posts: 762
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 33
Quote:
Originally Posted by coderguy View Post

From my understanding, the accuracy ratings you see I think are only for certain spectrums and wavelengths or types of light (around 2800).

Lux (lumen / meter^2) is a unit of illuminance and is a photometric quantity, which means that the power in each wavelength is weighted by the sensitivity of the human eye to that wavelength.

In contrast, Watt / meter^2 is a unit of irradiance and is a radiometric quantity, using absolute power without weighting by wavelength.

The bottom line is that the accuracy specification of an illuminance meter includes both the weighting by wavelength as well as the energy of the incident light, whatever the wavelength.

EDIT:
coderguy provided a link showing that some AEMC meters have worse accuracy on "common light" than 2856K (tungsten filament) light. The question is how much the filtered arc-lamp light from a projector differs from 2856K light.
jim2100 is offline  
post #103 of 391 Old 12-08-2011, 12:58 AM
AVS Special Member
 
coderguy's Avatar
 
Join Date: Dec 2006
Posts: 9,953
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 140
Those are a lot of big words you used which sounds like it came from a WIKI, but I'm just interpreting Page 2 as below:

http://www.aemc.com/products/pdf/2121.20.pdf

....And these are much higher-end meters...


Quick and Easy Shelf Mount Method for both one projector or dual stacks

Web Calculator v023 & v025
- Quick Peak at the new upcoming calculator
**Current Projector Calculator** -- http://www.eliteprojectorcalculator.com

Coder's Top Projector Picks of 2012 --http://www.avsforum.com/avs-vb/showthread....

coderguy is offline  
post #104 of 391 Old 12-08-2011, 01:17 AM - Thread Starter
Advanced Member
 
jim2100's Avatar
 
Join Date: Aug 2011
Posts: 762
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 33
Quote:
Originally Posted by coderguy View Post

http://www.aemc.com/products/pdf/2121.20.pdf

Thanks for the link.

So the worst case for those AEMC meters is 18% +/- 2 counts. If the CA811 were reading 20lux on the 200lux scale, one count would be 0.1lux. So the accuracy would be 18% of 20 + 0.2 lux = 3.8 lux.

As you say, the CA811 is a more expensive meter than the LX1010B. So the implication is that if the CA811 is only accurate to 18%, then the LX1010B should not be more accurate than 18%.

So let's round it up to 20% for the cheaper LX1010B.

20% of 20lux + 2digits = 4lux + 2lux = 6 lux.

20lux +/- 6lux gives a maximum of 26lux, which comes to 93 lumens for a 114 inch screen. Which is obviously still quite dim.
jim2100 is offline  
post #105 of 391 Old 12-08-2011, 01:26 AM
AVS Special Member
 
coderguy's Avatar
 
Join Date: Dec 2006
Posts: 9,953
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 140
The accuracy is stated as +- 5% for this meter which is most likely the 2856k measurment. How this all plays out, no idea as this is beyond my expertise, best just to have someone test it, besides it's on a curve.

The accuracy of ca-811 and ca-813 are both stated as 3% for a 2856k source, but vary for other "common light sources" by 18% and 11%, respectively.

So if a meter is only a + or - 5% accuracy for 2856k, compared to a meter at 3% for 2856k which has an 18% error, then what does that mean?

Could mean a much higher error than even 18%, given that the CA-811 is only 3% error at 2856k but still has 18% error on other "common light sources".


Quick and Easy Shelf Mount Method for both one projector or dual stacks

Web Calculator v023 & v025
- Quick Peak at the new upcoming calculator
**Current Projector Calculator** -- http://www.eliteprojectorcalculator.com

Coder's Top Projector Picks of 2012 --http://www.avsforum.com/avs-vb/showthread....

coderguy is offline  
post #106 of 391 Old 12-08-2011, 01:29 AM - Thread Starter
Advanced Member
 
jim2100's Avatar
 
Join Date: Aug 2011
Posts: 762
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 33
Quote:
Originally Posted by coderguy View Post

Why not just have someone test it at a low lux count and see,

Because high accuracy is not really relevant to the JVC lamp project. For this project, accuracy is not as important as repeatability and linearity, which are fine with the LX1010B. We are trying to answer a question about lamp dimming. We do not need to know whether the lumen measurement is accurate compared to a more expensive meter, only how much the measurement changes as the bulb ages.

Accuracy only came up here as to whether the meter was in the ballpark or not , i.e., whether it was reading 10x too low. Since that is well outside of any conceivable accuracy specification, then if it really were reading 10x too low, it would be a defective meter. But my guess is that the meter is okay, and the projector is just dim.

But feel free to compare the meters you own at 20lux (as measured by the most expensive one) and see how closely the cheaper one(s) compare. But if you do, please start another thread, since it is not very relevant to this thread.
jim2100 is offline  
post #107 of 391 Old 12-08-2011, 01:41 AM - Thread Starter
Advanced Member
 
jim2100's Avatar
 
Join Date: Aug 2011
Posts: 762
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 33
Please sign up now for the JVC lamp measurement project! Just post in this thread or PM me to sign up.

You can sign up now even if you won't be able to make any measurements until January.

We have 32 participants signed up for the project so far, but we need more people. I'd like to reach at least 50 people, and 100 would be even better!

Deadline to sign up is Friday, 9th December. Only 48 hours until the deadline!
jim2100 is offline  
post #108 of 391 Old 12-08-2011, 01:42 AM
AVS Special Member
 
coderguy's Avatar
 
Join Date: Dec 2006
Posts: 9,953
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 140
Well many people were buying the meter and I thought they might want to know what the accuracy was, and it definitely had some relevance to the overall topic even if it doesn't show a fault in the test, because my point was not to show a fault in the test, but was only to get to the bottom of some things that were posted earlier in the thread.

In essence I was just pointing out that the interpretation of the + or - 5% doesn't necessarily mean what it seems to mean, but you tried to techno-babble me into looking like I was making stuff up, so I had to respond. I'm not sure the accuracy of the meter overall, but I still wonder why reviewers can never agree on throw modifiers, that's all...

I'm not against the test, although I do see a few issues with it, but I think you got more people than I expected.


Quick and Easy Shelf Mount Method for both one projector or dual stacks

Web Calculator v023 & v025
- Quick Peak at the new upcoming calculator
**Current Projector Calculator** -- http://www.eliteprojectorcalculator.com

Coder's Top Projector Picks of 2012 --http://www.avsforum.com/avs-vb/showthread....

coderguy is offline  
post #109 of 391 Old 12-08-2011, 02:02 AM
Member
 
Shankar_v's Avatar
 
Join Date: Dec 2011
Location: Chennai, India
Posts: 28
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
1. X-90
2. Install likely early January
Shankar_v is offline  
post #110 of 391 Old 12-08-2011, 02:04 AM - Thread Starter
Advanced Member
 
jim2100's Avatar
 
Join Date: Aug 2011
Posts: 762
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 33
Quote:
Originally Posted by Shankar_v View Post

1. X-90
2. Install likely early January

X90, cool! Thanks for signing up!
jim2100 is offline  
post #111 of 391 Old 12-08-2011, 02:15 AM
AVS Special Member
 
blee0120's Avatar
 
Join Date: Oct 2009
Location: Merillville, IN 46410
Posts: 3,526
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 11 Post(s)
Liked: 53
My RS55 will be here Friday
blee0120 is online now  
post #112 of 391 Old 12-08-2011, 02:24 AM - Thread Starter
Advanced Member
 
jim2100's Avatar
 
Join Date: Aug 2011
Posts: 762
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 33
Quote:
Originally Posted by blee0120 View Post

My RS55 will be here Friday

So I can sign you up for the project?
jim2100 is offline  
post #113 of 391 Old 12-09-2011, 12:33 PM
Advanced Member
 
Gary Gleave's Avatar
 
Join Date: Sep 2001
Location: Calgary, Canada
Posts: 623
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
I'll take part. I received my 45 a couple of days ago. Does The Source carry a light meter that will do the job?
Gary Gleave is offline  
post #114 of 391 Old 12-09-2011, 01:18 PM - Thread Starter
Advanced Member
 
jim2100's Avatar
 
Join Date: Aug 2011
Posts: 762
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 33
Quote:
Originally Posted by Gary Gleave View Post

I'll take part. I received my 45 a couple of days ago. Does The Source carry a light meter that will do the job?

Thanks for signing up!

I am not familiar with "The Source". Did you see post #7 in this thread with several light meter recommendations? There are links to google shopping with several vendors to buy the light meters.
jim2100 is offline  
post #115 of 391 Old 12-09-2011, 11:08 PM
AVS Special Member
 
mnn1265's Avatar
 
Join Date: Jul 2004
Location: Wisconsin
Posts: 2,286
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I haven't received mine yet but I'll help out when it comes.
mnn1265 is offline  
post #116 of 391 Old 12-10-2011, 04:44 AM
Member
 
MadScientist-UK's Avatar
 
Join Date: Dec 2011
Location: Salisbury, UK
Posts: 20
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
My initial data reading:

1. 9th Dec 2011
2. X30
3. Calibration disc
4. 14 hours
5. 80% Normal
6. Normal
7. Zero
8. 30 min
9. 713 (± 8.5; n=4) peak lumens (measurements taken around centre screen region)

10. 85” screen
11. Throw distance 3.5m
12. Meter used: LX1330B
MadScientist-UK is offline  
post #117 of 391 Old 12-10-2011, 07:30 AM
AVS Special Member
 
blee0120's Avatar
 
Join Date: Oct 2009
Location: Merillville, IN 46410
Posts: 3,526
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 11 Post(s)
Liked: 53
My reading with 7 hours on my RS55 is 1050 lumens on the THX mode, which is the best viewing I can do in high mode. Basically the highest setting that I can watch. I prefer 14-15fL to watch blu rays, which I can get in normal mode with the aperture at -10 that gives me 435 lumens.
blee0120 is online now  
post #118 of 391 Old 12-10-2011, 09:35 AM - Thread Starter
Advanced Member
 
jim2100's Avatar
 
Join Date: Aug 2011
Posts: 762
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 33
Quote:
Originally Posted by mnn1265 View Post

I haven't received mine yet but I'll help out when it comes.

Thanks for signing up! What model do you have on order?
jim2100 is offline  
post #119 of 391 Old 12-10-2011, 09:44 AM - Thread Starter
Advanced Member
 
jim2100's Avatar
 
Join Date: Aug 2011
Posts: 762
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 33
The initial sign-up deadline has passed and we now have 40 people participating in the project! But I was hoping to get at least 50 participants, and more would be better, so I am going to extend the sign-up deadline.

Extended sign-up deadline: Friday, 16th December

If you have a new 2011-2012 JVC projector, or expect to have one by the end of January 2012, please sign up now! To sign up, you can PM me or post in the project thread:

http://www.avsforum.com/avs-vb/showt...4#post21276994

Participating in the project should only take a few minutes of your time each month.

If you don't have a light meter, you can order a cheap one online. See post #7 for recommendations.
jim2100 is offline  
post #120 of 391 Old 12-10-2011, 10:08 AM - Thread Starter
Advanced Member
 
jim2100's Avatar
 
Join Date: Aug 2011
Posts: 762
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 33
For reference, I copied down most of the text I could find on the lamp or lamp-housing from my RS45.

On the housing:
JVC 220W
Model: PK-L2210U
>PPS<<br /> CMX22283

On the lamp:
83 (in pencil on vacuum epoxy seal)
OT 723093JJ5 (or could end in 005, some ink was maybe missing)
QLL0194-003
PC010632399
HSCB220V2H
jim2100 is offline  
Reply Digital Hi-End Projectors - $3,000+ USD MSRP

Tags
Jvc Dla Rs45 Home Theater Projector 1080p Hdmi , Jvc Dla Rs55 Bundle , Jvc Pro Dla Rs65u3d Reference Series 3d Home Cinema 4k Projector
Gear in this thread

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off