Ok got ya, i have seen this i wasnt aware of the name, i saw it not long ago actually and yeah its real nice, its a shame desktop lcds dont utilise this kind of tech or we all would have brighter projectors, as for a cdm-t i think realy they are better suited for a dlp projector, with the nature of the bulb arc and its arc housing a shperical reflector is not realy in its best favour either, an eliptical reflector would be best for this kind of bulb over a parabolic as u can then run a full condenser set after the light, im going to try and get a hold of an eliptical reflector to see just how much more gain we have over a parabolic.
Trev
The only lazy thing with this is that I got 1500h to find a way to replace the orginal bulb with the a cdm-t bulb or something else, and that will not be a easy thing to do, but I think this is the furture diy-project.
I beleve this is the way to go, you get so much more for the money if you buy a used-commercialprojector, better contrast rate,S-Video input, RGBs-input, zoom and remotecontroll and many other things.
Mathias,
I see no reason why you could not use a condenser lens with the PAR reflector. Perhaps it is not ideal but neather are most of the reflectors being used in the DIY designed here and yet they yield good results.
The condenser lens just needs to be put put in close proximity to the PAR reflector before the light beam spreads out too much.
Also, good work on the PAR reflector. I think it was a good idea. I can no longer find the thread were you had the pictures for making the reflector. Can you post a link to the location if not too much trouble. Thanks,
Hezz
I see no reason why you could not use a condenser lens with the PAR reflector. Perhaps it is not ideal but neather are most of the reflectors being used in the DIY designed here and yet they yield good results.
The condenser lens just needs to be put put in close proximity to the PAR reflector before the light beam spreads out too much.
Also, good work on the PAR reflector. I think it was a good idea. I can no longer find the thread were you had the pictures for making the reflector. Can you post a link to the location if not too much trouble. Thanks,
Hezz
Yes I realized that, I though Ace ment another type of condensors. There are two way condensors are used, slide-projector-design and ohp-design, I think Ace mean the slide-projector thing and with that you must use a 10 degrees or smaller spreading angle reflector, because you must have parallel rays. But the slide-projector-design is just to get the light more even, it will not be stronger. In a ohp-design the condensor amplify the light from the bulb and that design will not work with a PAR-reflector.
I have never seen so big condesorlenses that you must use with the slide-projector-design, they must be atleast 100mm in diameter to fit a PAR30-reflector and forget magnifying glass, they change the color of the bulb so it looks green.
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I agree and have tried it, the model u have with the micro lens system is a worthwhile projector to retrofit but i think manny others that dont use this kind of tech wont be worthwhile doing with a cdm-t or the cdm-t sized 250w as the bulb wont be bright enough to get your image back to how it was originally
lol na the dual condenser system, condensers to work properly are actually meant to be used in pairs, they intensify the beam and can spread, even, or maintain the beam of light, pro projectors use them, the earlier ones that used the par reflector but now days u will find they use eliptical reflectors thus having the maximum light gain from the bulb and a focal point on the reflector to a single condenser system, the last par design u have draw will work but i would certainly hate the see the focasl of the frensel needed, it may be ok for a small lcd but u would want the reflector the same size as the lcd at at the right distances ofcorse.
Trev
sorry mathias i mis read your last pic very true it wont work with a ohp condenser, the only condenser to use for that would be somthing like a double convex and all that would realy do is intensify the light coming from the reflector, once again ok if u have a lcd the same size as the reflector and if u had that kind of a distance to the frensel wich no doubt would be long, even with that said u could ajust the light rays that are coming from that type of reflector to not come out so paralelle to suit a shorter focal system.
Trev
Trev
Thank you for some info on condensors.
The last design has a big problem and that is why I say it´s not working, you get a sharp picture of the reflector on the lcd, even if you get it out of focus, you can still see the reflector. I have tried that and it´s a really bad solution, don´t use it, it´s a waste of time. If you try to focus the light in the reflector and put a single condensors in front of it, the problem remain. So I recommend using the slide-projector-design.
The last design has a big problem and that is why I say it´s not working, you get a sharp picture of the reflector on the lcd, even if you get it out of focus, you can still see the reflector. I have tried that and it´s a really bad solution, don´t use it, it´s a waste of time. If you try to focus the light in the reflector and put a single condensors in front of it, the problem remain. So I recommend using the slide-projector-design.
Back to topics !
Here is a very interesting link, that I found on another forum, a 120W UHP is only output 7000 lm, and the one in my commercialprojector 130W will not be so much brighter. So I think there will not be a good chance the cdm-t will work really good.
http://www.lamptech.co.uk/Spec Sheets/Philips UHP120.htm
Here is a very interesting link, that I found on another forum, a 120W UHP is only output 7000 lm, and the one in my commercialprojector 130W will not be so much brighter. So I think there will not be a good chance the cdm-t will work really good.
http://www.lamptech.co.uk/Spec Sheets/Philips UHP120.htm
More condensors
A cdm-t-lamp is pretty big compared to a uhp-lamp, so to collect all light from the cdm-t lamp we need a bigger reflector a par30 works very well. But the parallel beam will be too large so we need it smaller, the same size as the diameter of the uhp-reflector. To make the beam smaller and more intensive, I found out that the slide-projector condensor-design should work, but with diffrent lenses. So with the cdm-t design we now have a very intensive and small light beam, that easily can replace the uhp-lamp, and it will last in 6000/12000h, sounds like a good deal to me?
But one thing I have noticed when I compared the diy and commmercial-projector is that the uhp-lamp is much whiter, the cdm-t is only 4200k against 6000-7000k for the uhp-lamp, and that is a big diffrens, the white looks dirty in the diy-projector, if I express the fellings.
A cdm-t-lamp is pretty big compared to a uhp-lamp, so to collect all light from the cdm-t lamp we need a bigger reflector a par30 works very well. But the parallel beam will be too large so we need it smaller, the same size as the diameter of the uhp-reflector. To make the beam smaller and more intensive, I found out that the slide-projector condensor-design should work, but with diffrent lenses. So with the cdm-t design we now have a very intensive and small light beam, that easily can replace the uhp-lamp, and it will last in 6000/12000h, sounds like a good deal to me?
But one thing I have noticed when I compared the diy and commmercial-projector is that the uhp-lamp is much whiter, the cdm-t is only 4200k against 6000-7000k for the uhp-lamp, and that is a big diffrens, the white looks dirty in the diy-projector, if I express the fellings.
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I would have to agree on that, the light is white but after going through the lcd's polarisers it looks a green tinge somtimes yellow, actually if u get yellow thats the quality of your frensels, also that dirty look is from the frensels also, page mags are bad at doing this but ive been finding out its also the tuning of your optics that makes the yellow look, while ive been tuning mine i can change the colour temp of my light just with tuning the frensels against each other, i can make the light a yellow dirty colour to a clean white colour, could be be from the angles of the light going through the frensels, i think your idea in the last post will work, have u thought in making a fiber optic light pipe? i think this would be very good for your projector and its not very hard to make.
Trev
I my case the projected light was not dirrent than it was from the bulb, the fresnell didn´t affect the whitecolor.
But one thing I know is that you don´t notice the lower colortemp, if you don´t have something to compare with. But the problem is not so very big, and there are other 150-250W bulbs with 6000k.
The fiber optic light pipe is a very intressting thing to make, but I wonder if you don´t loose much light with it, and it´s probably not so very cheap to make one.
Here is a problem with the diy-projector, and this was the first thing I noticed when I switched on my commercial-projector, In all diy-projector-designs I have seen here no one have solved this big problem. You can place a commercialprojector on a table and it´s not stand in the way for the picture. This is why you can mount a com-projector in the roof, without touching the keystone.
I know that the biggest main reason why not change a UHP-lamp to a cdm-t lamp is the problem that you must fool the projector that the uhp-lamp is ok. I did a quick test, took out the uhp-lamp and turned on the pj and yes it´s started, but the projector will be in warmup state, so I couldn´t turn it off but I think it´s possible to get a picture in that state. This is not a good solution so this is whats need to bee done:
Most new projectors has a maindriverboard and a separate powersupply-ballast-part, there is a cable connected between this two parts in my case the cable has 20-wires. I think one of this 20 wires will change it´s level when the projectorlamp has warmed up. So what I´m going to do is to measure all the wires and see which of them that change it´s level. When I have found the right wire, connect that wire with a 100-200 ohm resistor to the right voltage level, and the projector think the lamp is ok.
But first you have to by-pass the lampcover safety switch.
But one thing I have realizest is that the lamptime is not something you people need to be worried about: If you watch a movie one time a day 3h, a 1500h lamp will last in 1.5 years, I my case the lamp time was 20h after two weeks so the lamp will last in 3 years with that speed. Other commercialprojector lamps has a lifetime of 4000h, 3h a day and it will last in 3.6 years. In many cases I think the lamp will survive the projector, do you really want a 800*600 projector in 3 years ?
Most new projectors has a maindriverboard and a separate powersupply-ballast-part, there is a cable connected between this two parts in my case the cable has 20-wires. I think one of this 20 wires will change it´s level when the projectorlamp has warmed up. So what I´m going to do is to measure all the wires and see which of them that change it´s level. When I have found the right wire, connect that wire with a 100-200 ohm resistor to the right voltage level, and the projector think the lamp is ok.
But first you have to by-pass the lampcover safety switch.
But one thing I have realizest is that the lamptime is not something you people need to be worried about: If you watch a movie one time a day 3h, a 1500h lamp will last in 1.5 years, I my case the lamp time was 20h after two weeks so the lamp will last in 3 years with that speed. Other commercialprojector lamps has a lifetime of 4000h, 3h a day and it will last in 3.6 years. In many cases I think the lamp will survive the projector, do you really want a 800*600 projector in 3 years ?
Yeah but some are heavy users thats the thing, some want it to be like a normal tv, i myself will get another pro projector but id proberly go dlp when the tech is more refined, when the rainbow efect is more or less gone that is and the refresh rates are high, i find dlp is alot more eficient then lcd, but lcd has its good and bad points too, i recon a cdm-t would do well in a dlp as a retrofit, but alignment could be an issue, the projector u have purchased mathias is a nice one being it has that micro lens tech, as for sensors u should be able to get away with shorting the sensor to the earth or ground, ive done this before on variuos sensors and its never failed for me, temp sensors and things like that are ok to short out, somthing with thermo resitors ect, but id be carful with the bulb warm up one lol.
Trev
What I have understand is that the newest dlp-projectors already today beats a really expensive crt-projector, so lcd-projectors are probably gone in some years. A thing I have noticed is that 800*600 is a too low resolution I can clearly see all the pixels, it looks like if you sit 0.5 meters from a 28" TV. When I was watching my diy-projector with 1024*768, I couldn´t see one single pixels, so I really hope the 1024*768 projectors will get cheaper.
Lcd hasnt gone yet lol, lcos is lcd, and they far outrun any dlp or crt but ofcourse all for a price, but yeah i know what i mean with standard lcd going out, maybe, not sure, who knows, either way its still all in good fun, as for the reso's above, the projection lens can hide artifacts like screen door, not sure if your aware of it or not, but if u dont see any screen door u got a cheap blured lens, in some cases they use these to hide the screen door, also yours is a 3lcd unit so that might help also, the reso on mine isnt bad, at 12ft i cant see the screen door at all, thats on the lilliput but even with that said , this all depends on your projection screen and lens, and how sharp the image is.
Trev
Update
I have read in many AVS-forums now and it seems possible to buy a small UHP-lamp the small thing in the middle of the lampmodule, it should only cost €25 - 40, and replace the broken one. I think this is a much better solution than the cdm-t thing.
1. Don´t have to fool the projector that the lamp is ok.
2. Use the built in ballast.
3. No need to build something outside the pj-case.
4. Better colortemp, no need to add more fans.
The lamp voltage is marked in almost all new pj:s, so you only need to find one with the right voltage and powerrating.
If you can´t take out the broken lamp from the reflector-module it´s easy to build a new reflector with a small halogenrefector lamp. But be aware of that UHP-lamp can explode with great force.
I have read in many AVS-forums now and it seems possible to buy a small UHP-lamp the small thing in the middle of the lampmodule, it should only cost €25 - 40, and replace the broken one. I think this is a much better solution than the cdm-t thing.
1. Don´t have to fool the projector that the lamp is ok.
2. Use the built in ballast.
3. No need to build something outside the pj-case.
4. Better colortemp, no need to add more fans.
The lamp voltage is marked in almost all new pj:s, so you only need to find one with the right voltage and powerrating.
If you can´t take out the broken lamp from the reflector-module it´s easy to build a new reflector with a small halogenrefector lamp. But be aware of that UHP-lamp can explode with great force.
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