JVC 2011-2012 lamp measurement project

I am asking for volunteers with new JVC projectors to be part of a project looking to answer the question:

For new 2011-2012 JVC projectors, what is the chance of a projector lamp failing (catastrophically, or by excessive dimming) within 6 months or 600 hours?

If you have recently purchased (or have on order) one of the new 2011-2012 JVC projectors, and are willing to pledge a small amount of your time to providing data for this project, please either PM me or you can just respond to this thread.

The deadline for signing up for the project has been extended to Friday 16th of December. Note that you do not necessarily need to have your projector in-house by this date. You can still sign up now if you have a projector on order, even if you do not expect to receive it until sometime after Dec 9th.

To sign up, you should either have, or have on order, one of the following JVC projectors:

DLA-RS45 or DLA-X30
DLA-RS55 or DLA-X70
DLA-RS65 or DLA-X90

NOTE: You must be willing to post or PM your results either once a month for 6 months, or every 100 hours of lamp usage up to 600 hours.

We cannot obtain good statistical data if the people who have no issues stop reporting results after a month or two, and the people who do have issues continue reporting. That is why volunteers will need to follow through for 6 months or 600 hours, even if you are experiencing no issues.

When you post or PM me to sign up, please include:

1) the projector model that you will be providing data for

2) your best guess for when you will have the projector in-house and ready for measurements

3) whether you have (or intend to purchase) a light meter for brightness measurements. Note that a cheap light meter suitable for this purpose can be purchased for as little as $20. If you don't have a meter, check out post #7

We will need as many people as possible participating in this project in order to get meaningful results, so please volunteer if you possibly can. My hope is that, within 3 to 6 months, we will have evidence showing that either the lamps in these new JVC projectors are holding up well, or that the lamps are failing prematurely. If the latter, perhaps the evidence will be enough to entice JVC to make fixing this issue a priority.

I'm going to give an example of a procedure to use for brightness measurements. Note that you do not have to follow the exact procedure given here. You can choose any procedure that is convenient for you. But it is important that whatever procedure you use, you must do it exactly the same way for every measurement. This is necessary so that if there is a change in your measured value, we know that the difference (probably) comes from a change in the brightness from the projector lamp, and not because you changed the procedure.

If anyone has any suggestions or corrections for these procedures, please do not hesitate to post in this thread. I will update this post accordingly.

You will obviously need a light meter (aka luxmeter) to measure the brightness. If you don't have one, check out post #7

If at all possible, please check your lamp and lamp housing before you set up the projector. Record all numbers printed on the lamp or housing (serial number, part number, batch number) and post them in this thread.

If you expect to use your projector less than 100 hours per month, then you should report your data once a month. If you expect to use your projector more than 100 hours per month, then you should report your data every 100 lamp hours. The first measurement should be when you first set up your projector, as close to 0 hours on the lamp as possible.

For each measurement, follow the same procedure, for example:

1. Power on the projector and let it warm up for a set amount of time.

I suggest 30 minutes of warm-up time to be safe (it may warm up faster than that), but you can use any amount of time as long as you are consistent in each of your measurements.

While the projector is warming up, double-check the settings to make sure they are the same for each measurement:

• Lamp Mode : normal or high
• Lens Aperture Setting
• Lens Memory and Zoom Setting (16:9, 2.35:1, etc.)
• Masking
• Picture Mode
• 2D (not 3D) Mode
• Calibration: Gamma, Color Temp., Color Space, Contrast, Brightness
  Would be a good idea to save all the settings into a memory called something like "lamp measurement" so you can recall them whenever you make another measurement.

2. Display a white field that fills your screen

The image on your screen should be at the same zoom and focus every time you make a brightness measurement.

Typically you would display a "100 IRE" white field.

It is possible to get the JVC to display a 100 IRE field from the service menu. Enter the service menu by pressing (fairly quickly): up, down, right, left, OK. You may need to try it several times with different timing to get it right. Once the service menu comes up, navigate to Options, to Adjust pattern, then hit the right button several times to get to the white screen.

If you have an HTPC, you can download a .TS video file with a 100 IRE field here:

http://www.w6rz.net/
http://www.w6rz.net/irefield100.zip

If you are using a blu-ray player as a source, you may already have a calibration disc that can display a white field. If you do not have a calibration disc, you may be able to burn a DVD yourself, for example:

http://www.avsforum.com/avs-vb/showt...4#post12373254

3. Take brightness measurement(s) with your light meter

You should hold the light meter close to your screen (within a few inches) and facing the projector lens. You can use a tripod if you like, or you can just hold the sensor away from your body, making sure that no part of your hand or body is anywhere near the front of the sensor. The idea is for the sensor to have a completely clear field of view towards the projector lens.

The best procedure is to mentally divide your screen into a 3 x 3 grid (like a tic-tac-toe board) and take a light measurement at the center of each of the nine grid squares, then average them together (you can use the attached spreadsheet to compute the average if you like).

A quick and dirty procedure is to just measure the brightness at the center of the screen. If you do this, please at least move the sensor around a bit to find the maximum reading. This is easier if your meter has a MAX or PEAK function, but you can still do it manually by just quickly looking at a few slightly different positions near the center of the screen and recording the maximum.

You can report your measurement here in lux if you like. Or if you prefer, you can convert it to lumens. There is a nice spreadsheet file (from Ron Jones) that I have attached to this post that you can use to convert lux to lumens: you just enter your screen aspect ratio, diagonal size of the screen, and the lux measurement(s), and it computes the lumens. If you use the nine-point measurement technique, the spreadsheet will also take the average for you.

4. Report the measurement results

You can post your results in this thread, or PM the results to me. I will maintain a master spreadsheet with everyone's data so that I can analyze the data and post the aggregate results.

Please include the following information with your results:

1. Date of measurement
2. Model of projector
3. Source of white field used (service menu, w6rz, calibration disc, etc.)
4. Hours on lamp
5. Whether lamp was primarily used in Normal or High Mode (or hours each of normal and high if you know)
6. Normal or High Lamp Mode
7. Lens Aperture setting
8. Warm-up time between powering-on projector and measuring brightness
9. Measurement of brightness

If you need suggestions on how to measure the brightness, please post a question in this thread. I imagine you will get responses from people who are more experienced than I am at making those sorts of measurements.

This post has an attachment, a spreadsheet file written by Ron Jones, which can be used to convert your lux measurement to lumens. But it is not necessary to convert your measurement to lumens if you do not want to. A lux measurement can be reported directly, as long as you do not change your screen size between measurements.

 

Lux to Lumens Calc - v2g.zip 3.9033203125k . file

2012-02-12 Chart:



After we get more data, I plan to renormalize the "first" measurement for each projector to the average normalized brightness of all the other projectors at the number of hours of the first measurement for each projector.

Reserved 2

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

That looks like a decent meter for the price. Should certainly be good enough to measure brightness for this project.

Right, that is the LX1010B that I mentioned in my previous post. That is the cheapest light meter I have seen, but it should be more than sufficient for measuring lamp brightness.

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.

For the cheap light meters, yes, you would hold the sensor in front of your movie screen, facing the projector (it would take a more expensive meter to measure scattered light coming from the screen)

I'll update one of the first posts in this thread with some recommended measurement procedures in a couple days. I'm hoping we can get people (like zombie10K ) to post their suggestions and procedures for measuring JVC lamp brightness, and then I will compile everyone's best ideas into a recommended procedure for this project.

Thanks, that looks useful.

Also, do you have any suggestions for what sources people might use?

For people with HTPCs, they can just download a 100 IRE video file, like the 100 IRE field from here:

http://www.w6rz.net/
http://www.w6rz.net/irefield100.zip

But I'm not sure what is the easiest way for people who do not have an HTPC and need to use a blu-ray player for the source material.

Does anyone know a good, free video file with a white screen that people can download and burn to a DVD? Is there an easy way to burn that w6rz irefield100 .TS file to a DVD so that a standard player can play it?

Thank you!

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.