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JVC 2011-2012 lamp measurement project - Page 2

post #31 of 390
12/2/11 at 6:14am
Quote:
Originally Posted by jim2100 View Post


Everyone is free to compare the data to whatever standard they like. Do you have any suggestions on what we should compare the data with?

In my opinion, if the chance of failure in 6 months or 600 hours turns out to be more than 10%, then JVC has a problem with the 2011-2012 projectors and lamps that JVC needs to fix. If it is more than 20%, then JVC has a major problem.

Again, in my opinion, the chance of such an early failure should be only a few percent or less for a product like this.

I think it would be great to have people with other projectors (Sony etc) and models also reporting the same type of data. This way you can track not only how your pj is doing but how all pjs are doing, which are best, worst, and what the median base line is and what is a reasonable baseline etc.

It also would result in more widespread participation and for a project like this to be effective you need lots of data.

Maybe try reaching out to AVS member "coderguy". He runs the calculator web site and I think is interested in tracking this data too.
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post #32 of 390
12/2/11 at 6:36am
Quote:
Originally Posted by jim2100 View Post

Do you mean the projector will not be ready to go for about a month?

That is no problem. I expect some people will be signing up now but may not receive their projectors until late December or even January. That is also no problem.

The reason I am asking people to sign up now is that I want to avoid having people signing up in a couple months, mainly because they were having problems with dim bulbs. That would skew the results, since I guess if we wait a couple months, people who have had no issues will be less likely to sign up than people who had problems.

I will have my projector this next Tuesday, but my home theater is still under construction. I'm working feverishly with the small amount of time I have each day after the chillen' go to bed.

I will still be able to take an initial reading, though.
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post #33 of 390
12/2/11 at 10:46am
Thread Starter 
Quote:
Originally Posted by scoobygt68 View Post

So over in the other JVC X30 (RS45) thread I seen someone mention that the lx1330b meter is capable of measuring not only lumens but also the contrast????? I would certainly like the ability to measure contrast in addition to lumen output.

All the meter measures is the strength of the light. I guess what coderguy meant is that the LX1330B can measure weaker light than the LX1010B. However, I don't think coderguy owns that meter, so I'd like to hear from someone who does own that meter:

Is the resolution (minimum amount of lux measured) with the LX1330B, 1 lux or 0.1 lux?

I know with the LX1010B it is 1 lux. With the DT-1301 that I mentioned in post #7, the resolution is 0.1 lux.

But even 0.1 lux resolution may not be enough to measure contrast unless you "cheat" by holding the meter up right in front of the projector lens. Because a typical reading at the screen for a white field with a JVC would be 500 lux or less, and if the resolution is 0.1 lux, that gives you a maximum measurement of 500/0.1 = 5000 for the contrast. But the native contrast of the JVCs should be 50,000 or more.

EDIT:

I guess the best way to measure the native contrast would be to put the projector as close to the screen as you can while still being able to focus. This would obviously result in a ridiculously small picture, but it would increase the lux a great deal. If you could make the picture small enough to reach 50,000 lux on a white field, then even the LX1010B could measure a 50,000 to 1 native contrast ratio, albeit with large uncertainty since the dark measurement would be 1 lux +/- 0.5 lux. If you can make the picture small enough to get 150,000 lux on a white field, then the LX1330B should be able to make a decent native contrast measurement, I think.

Has anyone tried extremely-close projecting with JVC optics? What is the smallest picture that you can get in focus?
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post #34 of 390
12/2/11 at 10:50am
Thread Starter 
Quote:
Originally Posted by lovingdvd View Post

I think it would be great to have people with other projectors (Sony etc) and models also reporting the same type of data. This way you can track not only how your pj is doing but how all pjs are doing, which are best, worst, and what the median base line is and what is a reasonable baseline etc.

It would be nice to know what the equivalent numbers are for other projectors, but this is already a big project just for the JVC projectors. I'd be willing to assist anyone who wants to organize a similar project for other projectors. Are you interested in doing one? Which projector(s)?
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post #35 of 390
12/2/11 at 11:01am
Quote:
Originally Posted by jim2100 View Post

It would be nice to know what the equivalent numbers are for other projectors, but this is already a big project just for the JVC projectors. I'd be willing to assist anyone who wants to organize a similar project for other projectors. Are you interested in doing one? Which projector(s)?

I have the Sony VW95 and I'd be happy to post my measurements at 100 hour intervals. I have the initial measurement and am at about 80 hours now so soon will be at the 100 hour mark. I also recalibrate every 100-200 hours so my numbers will always be at D65. The numbers themselves of course will not be directly comparable to the JVC, but you could track the brightness falloff % over time to see how THAT compares.

Then again, having just one person's VW95 numbers won't be a great amount of help because maybe I have a bad or a great bulb etc. That is why it would be great for a project like this to involve many people and across many different machines. With a good enough sample size you would be able to rank pj manufacturers and models by how well their lamps hold brightness over time.

The project could be very useful for now, but looking ahead I suppose its value will diminish (or become unnecessary) once we reach the point where LED based bulbs become commonplace - but that's at least a few years out.
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post #36 of 390
12/2/11 at 11:32am
Thread Starter 
Quote:
Originally Posted by lovingdvd View Post

Then again, having just one person's VW95 numbers won't be a great amount of help because maybe I have a bad or a great bulb etc. That is why it would be great for a project like this to involve many people and across many different machines. With a good enough sample size you would be able to rank pj manufacturers and models by how well their lamps hold brightness over time.

It sounds like you want to volunteer someone else to do all the work!

As I said, doing it for the 2011-2012 JVC projectors is already a big enough project for me. But if you want to organize a similar project for other projectors, I will assist you as much as I can.
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post #37 of 390
12/3/11 at 11:53am
Thread Starter 
I have posted a draft of a brightness measurement procedure in Post #2.

Please have a look and post your questions or suggestions in this thread. I will update the procedure according to your suggestions.
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post #38 of 390
12/4/11 at 5:29pm
Thread Starter 
Anyone who has a 2011 - 2012 JVC projector on order (or already in your hands), please sign up now! The deadline to sign up is Friday 9th December.

You don't need to have your projector by Friday to sign up, you just need to have one on order.

We have 13 people signed up so far, but we still need a lot more people.

Just reply to this thread or PM me to sign up.
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post #39 of 390
12/4/11 at 6:25pm
Quote:
Originally Posted by jim2100 View Post

I have posted a draft of a brightness measurement procedure in Post #2.

Please have a look and post your questions or suggestions in this thread. I will update the procedure according to your suggestions.

Just one critical point to remember - If you calibrate your projector by adjusting the contrast control so that the maximum displayed white level is at or just above video level 235 (the reference video level for a 100% white test pattern), then your projector will be putting out more lumens with this 100% test pattern than if you had calibrated the projector to display the "whiter-than-white" levels all the way up to level 255. Some people like to be able to display above white video level to avoid "white crush" or clipping of the peak whites in the advent the video program material does include above white information, but this will reduce the lumens output when displaying a reference white level test pattern (or normal video programs). So it will be useful to know how the projector has been caliibrated for white level.
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post #40 of 390
12/4/11 at 6:37pm
Thread Starter 
Quote:
Originally Posted by Ron Jones View Post

So it will be useful to know how the projector has been caliibrated for white level.

Since the main goal of this project is to track changes in projector brightness, I don't think this should be an issue unless someone changes the calibration (without saving the old calibration) between one measurement and the next. Or am I missing something?

But I agree that it would be interesting to know that information. When people start posting their data, we can ask about it in this thread.
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post #41 of 390
12/4/11 at 7:05pm
I just ordered a light meter. I'll join the study.
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post #42 of 390
12/4/11 at 7:14pm
Quote:
Originally Posted by jim2100 View Post

The least expensive light meter I have seen that could be used for lamp brightness measurements is:

LX1010B Luxmeter, from Mastech
http://www.google.com/search?gcx=c&s...=lnms&tbm=shop

That one has a resolution of 1 lux (max 50,000 lux), so it will be fine for measuring bright scenes, like a white screen. But if you want a light meter that can also measure a bit dimmer light, here is one with 0.1 lux resolution:

DT-1301 Light Meter, from CEM
http://www.google.com/#sclient=psy-a...T-1301+digital

Another meter that has been recommended by several AVS forum members is:

LX1330B digital illuminance meter, from Mastech
http://www.google.com/search?gcx=w&s...=lnms&tbm=shop

I'll commit to participating Jim as it's a good cause especially given our past pains/issues. I should be taking possession of an RS55 in the next week.

However let me say as to the recommendations here, be careful because the real "cheap" models have an unacceptable (higher) accuracy error percentage and only the 1330 model here gives a fairly accurate reading (which I own and have been recommending on our owners thread for a year).

As to the other inquiry on the 1330, it is only a light meter designed to covert light into FC & Lux. It has no ability to determine contrast; I'm not even sure what that means.

Lastly, Ron's point is very valid for how each PJ is set for white levels (which could affect the Lux reading).

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post #43 of 390
12/4/11 at 7:22pm
Thread Starter 
Quote:
Originally Posted by krichter1 View Post

However let me say as to the recommendations here, be careful because the real "cheap" models have an unacceptable accuracy error percentage and only the 1330 model here gives a fairly accurate reading (which I own and have been recommending on our owners thread for a year).

For anyone who wants an accurate reading, meaning a reading that will agree with any other expensive meter out there so that you can compare lumen measurements with other people, I agree that is a consideration.

But for this project, all we are really concerned about is repeatability. If you use the same meter in the same light, will it give the same reading?

I have seen no issues with repeatability with the LX1010B or the DT-1301. I own both of them.

It would also be good if the reading is fairly linear, in case the lamp starts dimming we want to know how much it dimmed (20%, 50%, etc.). But I think even the cheap meter should have sufficient linearity for this project.

It all comes down to whether someone is buying a meter only for this project (in which case the $15 LX1010B should be fine) or whether they will also use the meter for other purposes as well, in which case people may want to get a more expensive meter.
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post #44 of 390
12/4/11 at 7:37pm
Good point.
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post #45 of 390
12/4/11 at 8:28pm
What is the difference between the 1330B and LX1330B besides ~$7 in price?
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post #46 of 390
12/4/11 at 9:06pm
Not sure where you're seeing that bro but I think they're one in the same (maybe the site you're looking at failed to specify the 'LX'. To my knowledge there's only the LX1330B. The ...zon has it for 3.5 bux!
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post #47 of 390
12/4/11 at 9:29pm
You have to put the meter on a tripod very near the lens to get accurate Native contrast readings with any of these meters, and you probably do need to get it to like 0.10+ for most meters. Contrast is just the difference between black and white.

I have a CA-813 and a Mastech lx1330b, and the Mastech lx1330b resolution was 0.1Lux I believe, but I have never used it for contrast readings. The lx1330b comes in a black zipper bag case.

I have never attempted taking a contrast reading on a really high native projector like a JVC, so I have never worried about it, but I have taking native contrast readings on lower contrast projectors with my other meter by following this article:

http://www.avsforum.com/avs-vb/archi.../t-755705.html

You wont get the last precision on a cheap Mastech, but I think you can still get a general idea even with a cheapo light meter. Hence, you can tell if you are getting closer to 20,000:1 or closer to 10,000:1 by using DarinP's trick in the above thread which increases measuring range by 35x (but I've never tried it). You probably need 0.01 precision though to do it accurately, but worth a shot for fun.
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post #48 of 390
12/4/11 at 9:46pm
Quote:
Originally Posted by krichter1 View Post

Not sure where you're seeing that bro but I think they're one in the same (maybe the site you're looking at failed to specify the 'LX'. To my knowledge there's only the LX1330B. The ...zon has it for 3.5 bux!

Thanks dude! Going to order one of these.
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post #49 of 390
12/5/11 at 7:04am
Sure I'll bite, given I have an RS55 on-order with AVS.
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post #50 of 390
12/5/11 at 7:22am
I'm in.

1) X30-WE

2) Before Xmas

3) Minolta 10-T
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post #51 of 390
12/5/11 at 9:08am
Thread Starter 
Quote:
Originally Posted by NiToNi View Post

I'm in.

1) X30-WE

2) Before Xmas

3) Minolta 10-T

Nice meter!
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post #52 of 390
12/5/11 at 3:46pm
I'm in with a RS45 and LX1010B Luxmeter hopefully shipped within a week.
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post #53 of 390
12/5/11 at 4:53pm
Count me in. I have meter on the way from Amazon. I also have Calman and Chroma 5 meter. Currently have an RS40 with bulb replaced recently (from JVC). The old lamp blew at @450 hrs. Once I get the meter, I will record RS40 for record. I have an RS45 on order, but may not go through with the purchase based on what I'm reading. I have A-lens and Lumagen, so not sure if I'd gain much.
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post #54 of 390
12/6/11 at 12:37am
Thread Starter 
Who is going to be first to post their initial brightness measurement for their new projector?

Also, please post any part numbers or serial numbers printed on your lamp.
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post #55 of 390
12/6/11 at 3:13am
Happy to provide data. I've got my X30. Light meter to be ordered.

Edit: I'm assuming replying to this thread constitutes signing up and no other input is required for now?

MS
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post #56 of 390
12/6/11 at 11:51am
Thread Starter 
Quote:
Originally Posted by MadScientist-UK View Post

Edit: I'm assuming replying to this thread constitutes signing up and no other input is required for now?

Yes, I've added you to the list. You make 23.

I'd like to get at least 50 people participating, so if you know anyone else with a new JVC, please encourage them to sign up.

I also started a very similar thread on avforum, in case people want to sign up there instead:

http://www.avforums.com/forums/proje...t-project.html
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post #57 of 390
12/6/11 at 4:56pm
As requested:

1. 6th Dec 2011
2. X30-WE
3. Lumagen Mini 3D, smallest 100 IRE window pattern
4. 1 hour
5. 95% Normal
6. Normal /High
7. Zero
8. 1 hour
9. 752 / 1170 lumens

Other info:

10. 110" screen
11. Throw distance 4.1 meters
12. Standard gamut, Natural mode, 6500K, Normal gamma, Contrast and Brightness at zero (OOTB)
13. Minolta 10-T meter

Didn't take 9 readings and averaged (ANSI) nor will I be going forward (too much hassle) but four quick readings towards the corners of the screen measured 170-180 lux versus 225 lux at the center, so quite a drop in brightness uniformity.
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post #58 of 390
12/6/11 at 5:00pm
Thread Starter 
Quote:
Originally Posted by NiToNi View Post

As requested:

1. 6th Dec 2011
2. X30-WE
3. Lumagen Mini 3D, smallest 100 IRE window pattern
4. 1 hour
5. 95% Normal
6. Normal /High
7. Zero
8. 1 hour
9. 752 / 1170 lumens

Thanks for posting! For future reference, you need not post on both AVS and avforums, I will monitor both threads. But if you want to post on both (to generate discussion, for example) that is no problem.
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post #59 of 390
12/6/11 at 5:59pm
Got word my RS-45 should ship tomorrow - count me on on the project...will be using a friends meter he got to monitor his RS-40.

Given I will be calibrated, do you have a preference about us reporting calibrated vs stock mode numbers? Or just report both?
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post #60 of 390
12/6/11 at 6:07pm
Thread Starter 
Quote:
Originally Posted by msamblanet View Post

Given I will be calibrated, do you have a preference about us reporting calibrated vs stock mode numbers? Or just report both?

I have no preference. Whatever you choose, just make sure that you do it the same way every measurement you make. So, if you change the calibration in the future, make sure you save the old settings so that you can temporarily go back to them to make future measurements.
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