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JVC RS40 Lumens - Page 2

post #31 of 292
I have no clue what THX does. All I can do is calibrate the gray scale, set the primaries and secondaries, and get the brightness for each of the primaries correct. In high lamp mode, low lamp hours, mid throw, I would expect maybe 5600 but I don't know. 350 seems low in high lamp mode.

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post #32 of 292
I just had my X9 ISF calibrated by Certified tech who is also THX certified. What a difference in the picture. I thought I had a good picture before. I have a 130" Cinicurve with an anamorphic lens. When he took all the calibrations it was way out. He spent 6 hours this saturday in the service menu bringing the picture into shape. One surprise was that 5500 kelvin was the best setting instead of 6500. The picture is so much better it is hard to belive. You should spend the money and have your projector calibrated by an ISF certified tech. I had 15.5 foot lamberts at the screen low power . For 3D (even put the glasses on the camera) I had 11.5 FL on the screen high power.
post #33 of 292
THX mode meets a certain calibrated standard as defined by the THX company. Therefore you are not allowed to change certain settings.
post #34 of 292
Quote:
Originally Posted by mark haflich View Post

By 30%, I am being conservative. I do not know the exact number. It won't look to ones eyes as being say 15 to 20% less bright, to ones eyes it might look 5% less bright. One must reduce the lumens by a factor of 4 to have it look 50% less bright. Calibrated, short throw, open iris, low lamp, low lamp hours I would expect less than 500 lumens. Long throw, partially shut iris, 200 lamp hours, I would expect something above 300 lumens. I am speaking of my unofficial expectations after calibrating a few 40s. I have no experiemce with ones at more than 10 hrs or so.

Hi Mark,

Thanks for your remarks.

First, let me state that I think the JVC models still look like great projectors. However, there is so much uncertainty concerning the actual versus claimed lumens, especially after a modest amount of usage, that it makes it very difficult for prospective customers to truly determine the correct screen material or whether these projectors are suitable for certain home situations.

You or Jason could help dispel that uncertainty by posting something similiar to Jason's measurements of previous models.

http://www.avsforum.com/avs-vb/showp...79&postcount=4

I'm not expecting a full review of the three models, but it would be extremely helpful if just the lumen measurements could be released in advance of the full reviews.

Please give this serious consideration.

Thanks.

Larry
post #35 of 292
I believe JVC has created a lot of confusion with this year's models by specifying the lumens output in a way similar to what most of the other top selling projector manufacturer's have been doing for years. That is, pick a mode that gives the highest reading (or at least close to the highest possible reading) and publish that. At least JVC, by listing the associated color temp. at 8500K, was telling us this was not for a mode well suited for home theater use. JVC made no claims about lumen output in a 6500K mode suitable for home theater use. There was a lot of speculation that it would be in the range of 900 to 1100 lumens, but that was just speculation and not a claim made by JVC. In past years it appears that the JVC's claimed lumens output was for preset mode at close to 6500K and for a mode that would at least be acceptable for some home theater users. By various published reviews previous JVC projectors from the past year or two once calibrated, and with an essentially new bulb, put out somewhere between 600 and 900 lumens at short to mid-throw distances. Of course how you set the zoom will make a difference and I don't recall the JVC spec. sheet for this year's models listing the F-stop change in going from one extreme of the zoom to the other. For example, a change from f=2.8 to f=4.0 would be a full F-stop. I have seen some other projector brands and models that do list this as showing up to a full F-stop change when set to long throw (which would equal 50% less lumens out for max. throw distance vs. min. throw distance.). I suspect these JVC projectors have less than a full F-stop change but it's probably at least 1/2 to 2/3 of an F-stop. Typically the longer the zoom ratio the greater the change in F-stop from one end of the zoom range to the other and JVC do have a fairly long zoom range my projector standards. For my RS40 I have posted the lumens I measured for natural picture mode, with color temp. set to the 6500K preset, lamp in high mode, iris open and near min. throw distance. I also posted how the lumens output went up when I just changed the color temp. preset to 8500K. I have not tested/measured to determine what preset combination, of picture mode, contrast, color temp., etc. provides the absolute max. lumens output, but I suspect that I could get higher readings (perhaps getting to JVC's claimed 1300 lumens), but such a mode whould just be a numbers game and of no practical real-world value for a "home theater" application.
post #36 of 292
Quote:
Originally Posted by LarryChanin View Post


http://www.avsforum.com/avs-vb/showp...79&postcount=4

I'm not expecting a full review of the three models, but it would be extremely helpful if just the lumen measurements could be released in advance of the full reviews.

Please give this serious consideration.

Thanks.

Larry

This was sorely missed this year from AVS. Once the reviewers all over the world starting getting early copies of the X3 and X7 in November, I thought for sure AVS would have done their 'unboxing' and early impressions as shown above. This didn't happen with this years release.

I wish I still had my RS40 for direct comparison, but I'd like to see some objective lumen comparisons between the RS40 & 50/60. We need someone to ring the red 'bat phone' at Cine4homes secret, underground testing facility.
post #37 of 292
Quote:
Originally Posted by zombie10k View Post

I wish I still had my RS40 for direct comparison, but I'd like to see some objective lumen comparisons between the RS40 & 50/60. We need someone to ring the red 'bat phone' at Cine4homes secret, underground testing facility.

Hi Jason,

Yes, I wish you were in a position to measure those two projectors in a consistent, unambiguous manner. However, the greater concern I have is the double whammy of getting lower than expected out of the box calibrated lumens, coupled with an abrupt drop off in calibrated output after a few hundred hours usage.

As Ron suggests, this whole lumens issue is a matter of managing the expectations of prospective buyers. Based on previous experience many folks were hoping for around 900 usable lumens with a reasonably low drop off with usage. With conventional 2D projectors that can comfortably be run in low lamp mode preserving lamp life may be a reasonable expectation. (I am running beyond the expected life expectancy of my DLP lamp and things look fine.) However, I am reading professional reviews that state that even in 2D most owners would be running in high lamp mode with screens exceeding 110"-116". With the advent of 3D high lamp mode is a necessity and with it we can expect even more loss of lumens with usage.

Larry
post #38 of 292
I have an x7 on order and this question is really bothering me. I think i'll cancel the order, unless Jvc comes up with a fix or something.
post #39 of 292
Quote:
Originally Posted by locutus2k View Post

I have an x7 on order and this question is really bothering me. I think i'll cancel the order, unless Jvc comes up with a fix or something.

I sold mine. I couldn't believe how dim it was for me when watching movies.
post #40 of 292
Quote:
Originally Posted by LarryChanin View Post

p off in calibrated output after a few hundred hours usage.

As Ron suggests, this whole lumens issue is a matter of managing the expectations of prospective buyers. Based on previous experience many folks were hoping for around 900 usable lumens with a reasonably low drop off with usage.

Larry

Larry, it would have been a dream if there was 900 usable lumens. I am at the shorter end of the throw and 455 in THX and 360 D65k is nowhere near 900 lumens.

I blindly jumped in because of JVC's previous reputation and praise from faithful owners. The new model advertised as 1300 lumens should not put out less light than last years model which has a lower advertised lumen rating.

I like the projector and thankfully have the HP screen to compensate, but will strongly reconsider next time waiting to hear all these results, instead of being the one reporting them.
post #41 of 292
Quote:
Originally Posted by zombie10k View Post

I blindly jumped in because of JVC's previous reputation and praise from faithful owners. The new model advertised as 1300 lumens should not put out less light than last years model which has a lower advertised lumen rating.

Ditto, but also as a current JVC owner I had expectations that were raised not only by my own experience but also by the repeated pre-release claims that the new models were brighter than last years.

This experience has soured my trust in JVC and they no longer have my loyalty unless they can resolve my X9 lumens issue satisfactorily. In the meantime I'm back with my RS35.
post #42 of 292
Quote:
Originally Posted by Arnies View Post

THX mode meets a certain calibrated standard as defined by the THX company. Therefore you are not allowed to change certain settings.

This year we have a THX Calibration mode. There is additional software which is available to THX certified techs which allows many of the basic settings to be further calibrated based on the specifics of the theater in which the projector is installed.

There is also similar software for ISF certified techs.

Chris
post #43 of 292
Quote:
Originally Posted by Mark_H View Post

Ditto, but also as a current JVC owner I had expectations that were raised not only by my own experience but also by the repeated pre-release claims that the new models were brighter than last years.

This experience has soured my trust in JVC and they no longer have my loyalty unless they can resolve my X9 lumens issue satisfactorily. In the meantime I'm back with my RS35.

you're not the only one.. several people have already canceled their orders hearing the information that is starting to come in regard the lack of lumens compared to last years models, specifically in the 50/60.

My RS40 was brighter at 150 hours than the RS50 was out of the box. this shouldn't be the case and eventually more reviewers will point this out.

If I had known this was going to be the case, I would have bought an RS35 and ran a 2 projector setup for 2D / 3D.
post #44 of 292
Quote:
Originally Posted by LarryChanin View Post

As Ron suggests, this whole lumens issue is a matter of managing the expectations of prospective buyers. Based on previous experience many folks were hoping for around 900 usable lumens with a reasonably low drop off with usage.

Quote:
Originally Posted by zombie10k View Post

I blindly jumped in because of JVC's previous reputation and praise from faithful owners. The new model advertised as 1300 lumens should not put out less light than last years model which has a lower advertised lumen rating.

Quote:
Originally Posted by Mark_H View Post

Ditto, but also as a current JVC owner I had expectations that were raised not only by my own experience but also by the repeated pre-release claims that the new models were brighter than last years.

Hi,

Whereas there are a couple of measurements of calibrated out-of-the-box output lumens for RS40s in the 800+ lumen range, I have yet to see a report for any projector in this series measuring calibrated lumens of much more than 500 lumens after 300 hours.

Although my enthusiasm continues to wane with each of these new troubling reports, I haven't completely given up on JVC yet. As I stated earlier in another posting it would be helpful to prospective buyers if JVC clearly stated what the design standard is for both calibrated lumens out-of-the-box and the lumens after a reasonably amount of usage. Without this knowledge it is really a crap shoot whether this projector will be suitable for the buyer's particular situation.

If it turns out that these early measurements are truly representative of what we should expect, then to maintain their fine reputation, it would behoove JVC to offer some sort of incentives to both existing and prospective customers. These incentives might be free spare lamps, extended warranties on the lamps, rebates, etc.

I have started to lower my expectations regarding what amount of usable lumens I should reasonably expect and have started to plan on what additional expenses I would have to add to the price of a JVC projector in order to maintain adequate performance for say the the published expected life of the lamp.

For example, if it turns out we can only reasonably expect 500 lumens after after 300 hours and that produces borderline performance, then perhaps we should add the cost of 10 lamps (3000 hour specified lamp life divided by 300 hours actual usable life). If a lamp costs $400 then that's an additional $4000 added to the cost of owning this projector.

Or perhaps this lower expected usable lumens means I have to replace my screen material to prolong performance. For example, here's an analysis I did of my situation:

Quote:
Originally Posted by LarryChanin View Post

I used Ron and FLBoy's screen calculators and came up with the following values for my physical layout:

For these calculations I assumed that the projector output would drop to 500 lumens after around 300 hours and hopefully stabilize there.

Code:
Material             FH       UM150      UM200      5D       D-L HP

Delv. gain          1.25       1.46       1.92     1.87        1.87

2D ftl              14.6       17.1       22.5     21.9        21.9

3D ftl               4.4        4.3        5.6      6.6         4.4

So for this relatively low lumen situation it looks like only the Ultramatte 200 or the Silver 5D would be satisfactory. Selecting the Silver 5D would permit the lumens to drop below 400 lumens and still produce adequate 2D and 3D results of about 16 and 5 foot-lamberts respectively.

So if I were to buy a new Stewart Silver 5D screen I might be able to reduce lamp replacements, or if the lumen decrease stabilized at around 400 lumens maybe the lamp could be used to its full published life expectancy. The cost of new material would probably be around $2000 so I would have to add it to the cost of buying this projector.

Just thinking out loud.

Larry
post #45 of 292
Thread Starter 
I owned the RS15 for quite a while, and have had the RS40 for a couple of months now, and started this thread. I use the projector for all my TV viewing, as I did the RS15. The RS40 after 300 hours has lost less lumens than the old RS15 did with a new bulb, that is the lamp is holding up somewhat better than the RS15 lamps did. But with a new projector, the amount of lumens in NORMAL lamp mode using the RS40 is less than it is with a new RS15. For what it's worth the old RS15 lamp did lose tons of lumens fairly quickly, and this lamp is holding up better, but it starts with less lumens on screen with a new lamp than the RS15 had.
post #46 of 292
Quote:
Originally Posted by uzun View Post

I owned the RS15 for quite a while, and have had the RS40 for a couple of months now, and started this thread. I use the projector for all my TV viewing, as I did the RS15. The RS40 after 300 hours has lost less lumens than the old RS15 did with a new bulb, that is the lamp is holding up somewhat better than the RS15 lamps did. But with a new projector, the amount of lumens in NORMAL lamp mode using the RS40 is less than it is with a new RS15. For what it's worth the old RS15 lamp did lose tons of lumens fairly quickly, and this lamp is holding up better, but it starts with less lumens on screen with a new lamp than the RS15 had.

This is exactly the info i'm looking for.
Do you have some numbers to compare?
What i want to know is if the old series on low lamp mode is brighter then the new? And do the old lamps age better then the new or not?
post #47 of 292
So how would I go about measuring the lumens? My RS40 has 20 hours on it and so far I am very happy with it, just out of curiosity I would like to measure the brightness though. I have a (cheap) lightmeter, do I put it in front of the screen, pointed towards or away from the screen? Any particular test pattern/image I have to use (full white screen I guess) ? I am new to this and am enjoying my projector as it is but would like to learn a bit more and get into calibrating it a bit later. Thanks
post #48 of 292
100 IRE pattern filling entire screen. Put meter at center screen as close to screen surface as possible, smile, say cheese, and measure.
post #49 of 292
Quote:
Originally Posted by ohotos View Post

So how would I go about measuring the lumens? My RS40 has 20 hours on it and so far I am very happy with it, just out of curiosity I would like to measure the brightness though. I have a (cheap) lightmeter, do I put it in front of the screen, pointed towards or away from the screen? Any particular test pattern/image I have to use (full white screen I guess) ? I am new to this and am enjoying my projector as it is but would like to learn a bit more and get into calibrating it a bit later. Thanks

You will need a 100% white screen. It's available in the service menu or on the AVS calibration disk which is downloadable here in the forum.

Point the sensor towards the projector as close to the center of the screen as possible and record the LUX settings. (Ideally you will measure all 9 points on the screen for an ANSI lumen measurement)

Lumens = LUX * SQ Meters of your screen.

Converted your screen size in inches to meters. For example, my Screen is 142" diagonal. 70" tall and 124.5" wide.

http://www.metric-conversions.org/le...-to-meters.htm

70" = 1.778 meters
124.5" = 3.1623 meters

1.778 * 3.1623 = 5.62 SQ Meters

So if I measured 70 LUX * 5.62 = 393 Lumens at shortest throw for a D65 calibration at 220 hours.

Make sure and take note of your throw distance to the screen. The projector is going to be the brightest at shortest throw and then degrade with distance as much as 30% to the longest throw.
post #50 of 292
Quote:
Originally Posted by zombie10k View Post


You will need a 100% white screen. It's available in the service menu or on the AVS calibration disk which is downloadable here in the forum.

Point the sensor towards the projector as close to the center of the screen as possible and record the LUX settings. (Ideally you will measure all 9 points on the screen for an ANSI lumen measurement)

Lumens = LUX * SQ Meters of your screen.

Converted your screen size in inches to meters. For example, my Screen is 142" diagonal. 70" tall and 124.5" wide.

http://www.metric-conversions.org/le...-to-meters.htm

70" = 1.778 meters
124.5" = 3.1623 meters

1.778 * 3.1623 = 5.62 SQ Meters

So if I measured 70 LUX * 5.62 = 393 Lumens at shortest throw for a D65 calibration at 220 hours.

Make sure and take note of your throw distance to the screen. The projector is going to be the brightest at shortest throw and then degrade with distance as much as 30% to the longest throw.

Thanks, that's a pretty good description. I was in the service menu a bit but couldn't find any test patterns, the only one I saw is the crosshairs for convergence.
post #51 of 292
Quote:
Originally Posted by ohotos View Post

Thanks, that's a pretty good description. I was in the service menu a bit but couldn't find any test patterns, the only one I saw is the crosshairs for convergence.

you should have a number of test patterns in the service menu if you scroll left/right on the remote control. There is 100% IRE, all primary colors, etc.

Please post your results when the hours are low on the lamp and see how you make out as the lamp ages. The original lamp in my RS50 dropped 35% in 220 hours. thanks
post #52 of 292
I've had good luck with my AEMC CA811 Lightmeter just FYI. One of the most useful tools for home theater IMO.
post #53 of 292
Attached is a little Excel spreadsheet I put together for use when using a light meter to measure Lux from the projector and have it converted to Lumens. It's set up for either a single point measurement (e.g., at the center of the screen) or for doing an ANSI 9-point set of measurements.

 

Lux to Lumens Calc.zip 3.380859375k . file
post #54 of 292
So I just did a quick measurement at 20 hours and get 790 lumens at a 13'2" throw. Not sure though about what settings to use to have the best measure, my RS 40 was on Natural and aperture fully opened.
post #55 of 292
Quote:
Originally Posted by ohotos View Post
So I just did a quick measurement at 20 hours and get 790 lumens at a 13'2" throw. Not sure though about what settings to use to have the best measure, my RS 40 was on Natural and aperture fully opened.
If your screen is 120", your about 2 feet away from the shortest throw. The results would be slightly higher if you were a bit closer. Natural mode with a new lamp should be close enough to d65 where you shouldn't need major RGB corrections. A D65 correction might bring you down to ~750 at the same hours.

Red will quickly drop, but right now the lamp is as good as it's going to get.

By Comparison, my RS50 with a brand new lamp can only get 550 lumens at the shortest throw possible. That would make your RS40 approximately 30% brighter than my RS50 which adds further to the question as to why there is such a difference.

No one seems to know why this is the case, as they are both advertised with the same brightness output.

Try to track the lumens every 50 hours or so to get an idea of how it dims over time. There isn't enough info yet to compare the various results out there. Mine dropped 35% in the first 220 hours. I'll check it again around 270 hours.
post #56 of 292
Quote:
Originally Posted by ohotos View Post

So I just did a quick measurement at 20 hours and get 790 lumens at a 13'2" throw. Not sure though about what settings to use to have the best measure, my RS 40 was on Natural and aperture fully opened.

For those of us following the results, it would be helpful to know whether your lamp was on high or regular mode. Zombie has been taking his measurements on high mode. Thanks.
post #57 of 292
I got lost in all the JVC threads.

Almost bought the RS50, but all the talk about the brightness issues scared me away.

Can someone who has compared them, tell me how does the brightness of the RS40 compare to that of the older series in low lamp mode, and after they have done a couple hundred hours.

I'm about to pull the trigger on one of the JVC's and i cant decide:

RS40 or RS25.

Considering they both have the same contrast and blacks, and are all similar except for more calibration options on the RS25, i want to take the one that will hold its brightness for longer.
post #58 of 292
Quote:
Originally Posted by Grampa View Post

For those of us following the results, it would be helpful to know whether your lamp was on high or regular mode. Zombie has been taking his measurements on high mode. Thanks.

That was in low mode, just tried in high and I get 1106 lumens there.
post #59 of 292
Quote:
Originally Posted by Verners View Post

I got lost in all the JVC threads.

Almost bought the RS50, but all the talk about the brightness issues scared me away.

Can someone who has compared them, tell me how does the brightness of the RS40 compare to that of the older series in low lamp mode, and after they have done a couple hundred hours.

I'm about to pull the trigger on one of the JVC's and i cant decide:

RS40 or RS25.

Considering they both have the same contrast and blacks, and are all similar except for more calibration options on the RS25, i want to take the one that will hold its brightness for longer.

I have RS40 and it's great, but had I choice to buy RS25 for comparable price (w/warranty) I'd surely get it instead. Seems like less of a chance for issues.
post #60 of 292
Quote:
Originally Posted by ohotos View Post

Not sure though about what settings to use to have the best measure, my RS 40 was on Natural and aperture fully opened.

Quote:
Originally Posted by ohotos View Post

[...], just tried in high and I get 1106 lumens there.

Hi,

Thanks.

That is the highest reading I have seen using a useful picture mode.

Can you please list the rest of your settings?

Thanks.

Larry
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