Please post experience of JVC HD750/350/550/950 bulb lifetime / lamp brightness drop - Page 18

Please report your results!

Mine has about 850 hours and I also found small pieces of glass/ceramic when I removed the lamp for cleaning. My debris looked to be from the ceramic part that the lamp housing seats against and not from the lamp assembly itself.

Here is the post from earlier in this thread in case you missed it.

The cause? Repeated heating and cooling I'd imagine.

Jeff

Very unlikely; UV is hard to reflect efficiently and it has a tortuous path before it gets to our eyes.

Sorry for the projector newb and slightly OT question, but how do your projector back in the exact same spot after moving it and opening it up? I want to clean mine but fear getting it back to the sweet spot.

Mark its position as best you can before you move it and put it back as close as possible. Then move it in tiny increments while it's projecting some edge to edge image until the image falls perfectly on the screen. This assumes you are careful and don't disturb the lens shift settings. But a little adjustment after placement to make it perfect never hurt anything.

I am able to access and clean mine from a ladder, without taking the unit down. This is probably going to be a bit more difficult if the new RS series proves this cleaning is necessary, because the unit is a few inches deeper and I'll have less room to maneuver between the back of the unit and the back wall.

This is a very delicate procedure. Cleaning the projector should be done where you and the projector are very stable.

Jeff

With all the optical parts and the lens itself, I would like to think that most if not all UV light from the bulb is filtered out before it leaves the projector.

I seriously doubt that any is being reflected off our screens back at the audience. I wouldn't want to stand at my screen and stare into the light.

Jeff

Yeah, besides, I think projector owners with these bulbs would start to get sunburned...lol...they'd have 'red-push' visible on their faces and need some CMS work

Imagine wearing sunscreen when watching your projector. I just thought of another way for people to lower the black levels of their projectors. Wear sun-glasses. Why bother with a gray screen or filter on the lens? Just wear a pair of ray-bans and I guarantee you won't see black bars for 2.35:1 films and all space scenes will be deep black! And of course, you won't blind yourself either.

Someone should test that theory with an off the self UV meter.

1. Reflected light off the projector screen
2. Off the projector lens directly
3. Plasma TV
4. LCD TV
5. Outside with an overcast sky
6. Outside in a sunny sky

LOTS of things reflect UV. It's very easily reflected by many things as any of us high-altitude mountaineers know. A hat just doesn't cut it by itself.

But I "seriously doubt" any UV you may get from a theater screen is anything but negligible.

Any others here you know of besides Craig? We have manly men amongst us! Or maybe his specialty is rock and not the high atltitude. Still manly

Nope. My g'friend though HT enthusiasts were pasty-faced overweight uber-rich guys 'till she met me. I've shown her Craig's tag-line too as further evidence.

I'm only happy above 8,500 feet and prefer to be just below tree line at 10,000 feet or so. Sunscreen and UV rated glasses are our friends! And, the damn bear don't bug me up there. Man, have they gotten smart!

I have no problem at 12,000 plus, just getting their. If you think I move slow at 5000 you should se me anti flash at 12,600. Now with a road and a decent car and good weather, I am fine. But get out and hike up a few more hundred feet, it ain`t pretty.

looks like you camp at the low trail head then.....and sleep with the bears

I did spend 3 days at Brooks Falls in Katmai sleeping with the bears. Actually they were mostly eating salmon and had no interest in me. A mother and one cub curled up on the lake shore about 75 ft from me. Got some nice photos with the low Alaskan sun high lighting the bears with back light.

I have seen bears or rather a bear real high up on Danili maybe at 18,500 in the snow looking for buried waste food. But I was flying co piot in a small 4 seater being flown by Lowell Thomas`s son and were were up there to take some high shots of Denali.

You are a real "he man" out there with Griz... especially 75 feet from a mom and her cub. I'd have left. I may be a mountain man, but you'll never find me in Griz country. Yikes... those... well... I hope I don't get an infraction for saying this right out: I'm a pussy. To quote Jayne: "I don't wanna get et!" So where's that quote from? Movie? Character?

Black bear... I can deal.

I'm just curious, Mark. Are you a pilot or did you just happen to be sitting in the right hand seat? Sounds like a lot of fun.

I finally got around to trying this... My bulb is at 635 hours (original bulb that came with the RS20). I don't have equipment to measure lumen output, but after cleaning the integrator lens, the difference was dramatic.

Pretty amazing.

Jay

Yes, and the conventional wisdom seems to be that checking it every 100 hours might be a good thing.

Jeff

I cleaned my RS-10 with great increase in brightness. Like a few others have reported, my bulb has a crack in what I suppose is heat absorbing glass on the front of the bulb assembly. Nonetheless, the bulb works good. Has anyone experienced total bulb failure? I know that many people have replaced the bulb because their image was getting darker, or the hour count was getting high, but have any bulbs completely failed and been replaced?

I am not sure if this has been covered but is this something that I could do with an RS1.
Is a dirty lense a problem? I have about 500hrs on my 2nd bulb. I changed my first at 1400 hrs.
If cleaning is recomended, where can I find instructions on how to clean?

Thanks much
Tony

Tony, I'm not familiar with the internal configuration with the RS1, but it shouldn't be a big deal to pull the bulb and take a look inside with a bright light. If anything looks hazy, gently clean it with a microfiber cloth. With the RS-10, the biggest hassle is moving the pj to a work space. The actual cleaning takes about five minutes.

Did your bulb fail, or did you replace it because of age and brightness?

Age mainly, I didnt think the brightness was that bad. Until I changed it, that is!

I've got over 1900 hours on my HD1/RS1, but it still seems bright enough to me, I got just over 9ftL at 100 IRE from a recent measurement - campared to a 12ftL from the last calibration, but not sure how many hours were on the bulb at the time but it was done about 18 months prior so probably less than half.

How du you measure a lumens figure, can it be done using a colorimeter?

Are there any other side effects caused by a well used bulb apart from the obvious dimming? Can it actually be beneficial in terms of black levels?

I use to pilot but I lost my medical when I become an insulin shooting diabetic. So I can`t take off or land. But I can still fly in the co pilots chair though not commercially and many of my friends have instructor ratings so on cross country I do fly a bit.

In DSalmon season, the bears just eat. hey only interest they might have in you if you are fishing below the falls and see you catch one. The drill is if the bear is coming to you line to take the fish, you cut the line quickly and the bear grabs the fish and goes happily on its way not even thanking you for its nibble. And I mean nibble. These bears eat almost 24/7 when the fish are polling before the falls and attempting to run the bear gauntlet at the falls.

IC... makes sense. Thanks. Yeah... and even with black bear if they manage to get your food out of a tree you just let 'em have it. What's yours is yours, what's mine is... um... yours. Pack your gear and leave. In the old days you could bang cooking pots, but now they just regard you as you're banging away... so bored with it all. OK, I swear, no more OT. But I'm at my in-laws-to-be and I need something to do. No, really, they're great!

At Brooks falls they have Cabins that sleep four, absolutely nothing allowed the cabins that a bear might like, even tooth paste. No chewing gum. Nada. All meals are taken in the lodge and any food you bring like gum etc must be left there. For camping, there is an electrified fence and a electrified fenced and protected food locker and cooking and eating gear must be left there as well.

The bears eat salmon. Unless you have a salmon on your line the could care less about you photographing them. In the old days, you had to walk a trail to the falls and bears with Salmon would cross your path, 10 ft away. You did make noise while walking. Now a days its primarily all elevated walkways. The female mothers always need to protect their cubs because the male bears will kill them given a chance. Its amazing to see a 200 lb mother chasing a big male bear away. She can be vicious and the male bears run from here. At night she will get away from the falls and catch a nap with her cubs curls up in little cavities dug out in the sand. The cabins might be 60 ft away and one gets up in the night, its still almost 24 hours light in July up there, with low sun across the lake and shots are easy. Maybe 40-50 ft away. Interesting volcanic rocks float in the lake

Quote:
Originally Posted by RonF
Hey so are any of these scrub clean stories and pics with RS25s or 35s? I just opened my 25 up because I needed to swap lamps and of course all eager to see if I had any of that crap on my "prism thingy". 870 total hours. Nada, zip, zilch in the way of haze. And I run on high lamp always. At first disappointed because no gain to be had by cleaning. But actually a good thing. Shouldn't have to worry about it if it hasn't happened by now. Mine was in the very early shipments last year from AVS.


I changed again today from an 820 + hour lamp back to an 180 hour lamp thant I want to keep for max demo purposes. Jeff Maier is coming in Wed so that is a good broken in # of hours and shouldn't change a whole lot over the next several hundred once he optomizes with it in there.

So I did do the micro fiber wipe. For reference, my RS25 has around 1,000 total hours on it now being run on high lamp but with the altitude setting for max fan, inside of a projector module with another strong fan blowing out along the exhaust side of the projector.

I could see maybe a tiny amount of very light colored residue on the fabric and could feel the surface go from a tiny bit sticky to feeling slightly smoother. Looking at the glass with a bright LED light, it does appear just slightly more clear. So maybe the 25 is not quite as subject as earlier models, or the high fan setting even with the lamp on high the whole time has helped keep too much heat from causing much buildup in my situation.

Slightly more clear though on the glass I believe.