Finally have an Rs 40 & 50
Quote:
Originally Posted by cossie0 /forum/post/20708220
Hi guys, a bit off topic but why do lamps dim over time?
Do normal household light bulbs dim over time as well as it is not something I can say I have noticed.
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Originally Posted by Geof /forum/post/20706365
Larry,
I have no knowledge about a new lamp design and that is why I said it's a newer lamp, which I believe to be true. They may have made subtle design changes and/or production/manufacturing improvements, or even sprinkled it with pixie dust, but hopefully the "7's" solve "5's" problems!
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Originally Posted by Shagg /forum/post/20709123
Is the number viewable by just taking off the back cover, or do you need to remove the lamp to see it? I was just wondering if it was easy/quick to check which lamp I have.
Quote:
Originally Posted by Geof /forum/post/20708864
I'm not an expert in lamps nor do I understand the physics behind UHP lamps but there are significant differences between a household lamp and a UHP Mercury Lamp. The household (Edison) lamp has a tungsten filament that glows because enough current runs thru it to make it hot. A UHP lamp does not have a filament. It has two tungsten electrodes that do not touch. A arc is established between those two electrodes and this arc in combination with Ultra High Pressure (UHP) gas (mostly mercury) causes it to create a very intense light source. The amount of lumens produced are dependent on the arc gap distance and the pressure of the mercury vapor. As the electrodes wear the arc gap widens causing dimming. The gap widens because the tungsten electrodes wear but the tungsten doesn't disappear....it gets deposited on the inside of the lamp and this tungsten coating reduces the amount of light passing thru the glass and this results in dimming. Phillips adds a bromide (IIRC) to help keep the tungsten from coating the inside of the glass and this helps reduce dimming but I not sure if other mfgrs do similarly. I'm sure there are other factors as well but that is beyond my understanding.
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Originally Posted by Shagg /forum/post/20709185
Very nice summary.
It's also important to note that on/off cycles (especially igniting the arc while the bulb is still hot) are in many ways more important to wear/dimming than the total hours.
Planning your viewing so that you can keep the PJ on instead of turning it off several times between movies/shows, as well as making sure that you let it cool down completely before turning it on again (not just the minute or so that the fan runs), can help extend the bulb life. I'm only at around 180H on my current bulb, but so far it has been pretty consistent with it's lumens. Not sure how much of that has to do with the above, vs the luck of the draw in getting a good lamp.
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Originally Posted by zombie10k /forum/post/20709224
This way I can save the precious JVC lamp hours for critical viewing or 3D.
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Originally Posted by Shagg /forum/post/20709293
Minor comment, but I think it's the "precious JVC power on's" that are actually more a factor than the "precious JVC lamp hours"... at least to some extent. From what I understand, igniting the arc between the electrodes causes more wear than letting it run after it's been ignited.
I'm sure there's a point at which it shifts the other way, IE you wouldn't want to just put the PJ on "hide" for 8 hours at a time (extreme example). But somewhere in the middle there is a balance between on/off vs hours. The important part is to understand that it's not just hours that we should worry about. For example, if you're watching two 60 minutes shows and turn the PJ off for 15 minutes between them (120 total "on" minutes), you're probably causing more wear on the bulb than if you just let it run for 135 minutes.
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Originally Posted by zombie10k /forum/post/20709463
hopefully one day JVC will lead the LCOS market with an LED light engine in the next few years. Someone is going to do it at a reasonable price (under 7k market), who will it be though.
Quote:
Originally Posted by Shagg /forum/post/20709293
Minor comment, but I think it's the "precious JVC power on's" that are actually more a factor than the "precious JVC lamp hours"... at least to some extent. From what I understand, igniting the arc between the electrodes causes more wear than letting it run after it's been ignited.
I'm sure there's a point at which it shifts the other way, IE you wouldn't want to just put the PJ on "hide" for 8 hours at a time (extreme example). But somewhere in the middle there is a balance between on/off vs hours. The important part is to understand that it's not just hours that we should worry about. For example, if you're watching two 60 minutes shows and turn the PJ off for 15 minutes between them (120 total "on" minutes), you're probably causing more wear on the bulb than if you just let it run for 135 minutes.
Quote:
Originally Posted by jgv1 /forum/post/20710287
If this has already been posted sorry, could not take the time to read all of the replies. Seeing this is an issue with the RS50 was what we were looking for
We have a customer having this issue with his RS50. Rep had suggested cleaning the lamp window input.
Waiting for lamp to arrive so we can try this first. Attachment 217780
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Originally Posted by jgv1 /forum/post/20710287
Waiting for lamp to arrive so we can try this first. Attachment 217780
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Originally Posted by Shagg /forum/post/20710412
Note that the JVC maintenance advisory does not list the RS40/50/60 models. It only lists up to the RS20/25.
Was it a JVC Rep that suggested cleaning the lamp window for a RS50?
Quote:
Originally Posted by Geof /forum/post/20708864
I'm not an expert in lamps nor do I understand the physics behind UHP lamps but there are significant differences between a household lamp and a UHP Mercury Lamp. The household (Edison) lamp has a tungsten filament that glows because enough current runs thru it to make it hot. A UHP lamp does not have a filament. It has two tungsten electrodes that do not touch. A arc is established between those two electrodes and this arc in combination with Ultra High Pressure (UHP) gas (mostly mercury) causes it to create a very intense light source. The amount of lumens produced are dependent on the arc gap distance and the pressure of the mercury vapor. As the electrodes wear the arc gap widens causing dimming. The gap widens because the tungsten electrodes wear but the tungsten doesn't disappear....it gets deposited on the inside of the lamp and this tungsten coating reduces the amount of light passing thru the glass and this results in dimming. Phillips adds bromide (IIRC) to help keep the tungsten from coating the inside of the glass and this helps reduce dimming but I not sure if other mfgrs do similarly. One other factor that wears the tungsten electrodes happens when turning the lamp on. Striking the arc wears the electrodes down and is supposedly equivalent to 30-60 minutes of run time. It's best not to keep turning the lamp on and off. I'm sure there are other factors as well but that is beyond my understanding.
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Originally Posted by zombie10k /forum/post/20709224
I solved that problem by picking up this little LED pocket projector. It puts out a solid 300 lumen (my RS50 is down to 360) and works perfect with my HP screen. I use it mainly for quick on/off TV shows, kids shows, etc. This way I can save the precious JVC lamp hours for critical viewing or 3D.
It looks better than most would think for it's size and also has near dead-on greyscale calibration out of the box.
Quote:
Originally Posted by Shagg /forum/post/20710412
Note that the JVC maintenance advisory does not list the RS40/50/60 models. It only lists up to the RS20/25.
Was it a JVC Rep that suggested cleaning the lamp window for a RS50?
Quote:
Originally Posted by zombie10k /forum/post/20709224
I solved that problem by picking up this little LED pocket projector. It puts out a solid 300 lumen (my RS50 is down to 360) and works perfect with my HP screen. I use it mainly for quick on/off TV shows, kids shows, etc. This way I can save the precious JVC lamp hours for critical viewing or 3D.
It looks better than most would think for it's size and also has near dead-on greyscale calibration out of the box.
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Originally Posted by Joseph Clark /forum/post/20711463
This is the Vivitek Qumi, right? Do you have any info on when the 500 lumen version is due out? I'm thinking of doing the same thing.
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Originally Posted by zombie10k /forum/post/20713237
Joseph - Hi, i've been following these LED's for a while, it looks like race is on between Acer and Optoma for the 500 lumen models. I believe Optoma said not until October (along with the 1.4 GT750) on their facebook site.
This leaves Acer to see if they can jump in sooner for August/September. This little QUMI is a marvel of modern science considering it's size and overall nice IQ. It's not much dimmer than my RS50 now @ 360 lumens and the gray scale was nearly dead on out of the box so face tones appear accurate. The saturation is a little hot.
it works well with the big HP in a dark room, the 500 lumen model would be perfect as a 'TV' projector used for quick on/off whenever you feel like it. The resolution of the new DLP chip appears higher than the Acer by a bit because of the diamond shaped pixels (text suffers though for windows desktop use).
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Originally Posted by Geof /forum/post/20713226
I'm sorry, I did not see this post until now but I do not know the answer. I never removed the lamp cover from my RS50 and I've sold it locally and no longer have it (and I'm still waiting for my RS40 to arrive). When I get the RS40 I'll look to see which series lamp is installed.