diyAudio Forums Archive - Put a HQI-bulb in a commercialprojector

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Put a HQI-bulb in a commercialprojector - Click HERE for Original Thread

mathias

I have now finished my diy-projector, consisting of a 15" TFT and a 150W cdm-t bulb, and a new light engine that use most of the lumens the bulb produce (more info about how the lightengine works you can find in the thread "videoprojector part II" page 116), I惴 satisfied with the picture quality and the brightness. But the diy projector is too big and beautiful isn愒 it. It looks like a nuclear-missile, And if I mount it in the roof I will get pretty flat if it falls down :)

So I have thought of an other idea: Buy a cheap commercialprojector, people are selling them cheap sometimes because they can愒 afford to buy a new bulb. Replace the expensive UHP-bulb (Ulta High Preformance) with a cheaper HQI-T 150W bulb, of course I have to use an external ballast. My question is what ANSI-lumen can I expect if I do that ?
Let say the commercialprojector use a 150W UHP-bulb and give 1000 ANSI-lumen with that.
Is the UHP-bulb so much more effective than a HQI-bulb ?
Will it be brighter than my diy-projector ?

golftdibrad

I think the trick will be to
1.trick the projector into thinking the bulb is fine
2.Focusing the parabolic reflector from the old bulb with you new, cheaper replacment. Kinda like your picture. this would give you about the same ansi lumens (assuming the bulb your using has the same lumen output as what its replacing)
3.Fit you cheaper and probally larger bulb into the space intended for that tiny blub.
If you could overcome these problems this would be a very cost-effictive way to go with a DIY projector, and alot nicer too. Plus the pj would be BEHIND the seating area.

Let me know if you try this, i'd be very interested in the results!

msx-2

i tried to do this with my proxima dp2800. However space is very limited and the light path is far from perfect(dp2800 uses about 4 first surface mirrors ,and the beast is a hell of a difficult machine to get apart (never seen a electronic device so difficult to dissasemble). Maybe in the future i take the thing apart and put it into a new housing. However, i think my lcd-controller is a little screwed up . There is some kind of raster over the projected image (its not the fresnell) .It's very strange and i don't know what it is.

Hezz

I wouldn't be surprised if some of that OEM bulbs specialness is marketing hype. The only issues I can see that you need to deal with are element alignment and UV and IR issues. For instance the OEM bulb may have IR glass around it to reduce the heat output.

Hezz

mathias

If I can in some how put the HQI-bulb in right place and focus it, and I mayby need to put the bulb a little outside the commercialcase in a extra box, but does anyone know if I can turn of the message "Please change the bulb" that I have seen in some shop ?

Which projector will be brightest and the best choich ?

1. Diy 7" TFT lilliput, with a 150W HQI, 200:1 contrast, 800*480 res.

2. Cheap commercialprojector 3 panels TFT 400:1 contrast, 800*600 res, change bulb to a 150W HQI.

I have seen some old projectors on the market that use one 6" TFT panel and a 250W HID, and this this thing only put out 250 ANSI lumens, wouldn愒 the 7" TFT lilliput thing get less bright ?

mathias

I finally bought a cheap commercialprojector, I couldn愒 resist, the price was only what you pay for two 15" tft monitors. Well the UHP-lamp will last in 1500h and a the price for a new one is the same as for a new 15" tft. So of course I will not buy a new lamp-unit.
I found out that a UHP-bulb is actully the same as a HID short arc lamp, so the only diffrents between a HQI and a UHP is that the arc is smaller in the UHP, the light output is the same.

The UHP-lamp unit puts out a parallel beam that is 50mm wide. I think it愀 not so difficult to build a HQI-light unit that puts out a parallel beam of that size. And because the light is parallel we can use a mirror so we can place the light-unit outside the pj-case.

mathias

UHP-unit front picture.

mathias

I asked before which of the two choiches below that are the most worth to buy.

1. Diy 7" TFT lilliput, with a 150W-250W HQI, 200:1 contrast, 800*480 res.

2. Cheap used commercialprojector 3 panels TFT 400:1 contrast, 800*600 res, change bulb to a 150W HQI.

I did a very intressting comparision between the two choiches.

The pictures to the right are the diy-projector and to the left the commercialprojector. The pictures up is with the lights on, and down it愀 off. The diy-projector, consisting of a 15" TFT and a 150W cdm-t bulb, and the new light engine with a PAR30-reflector. Because I use the PAR30 reflector it will be equal to a 7" -design.

The pictures are taken with the same camra, same dvd-player, same surrounding light and same screen-size 100". My camra don愒 like dark pictures, so what seems dark is not so dark. Which would you choose ?

mathias

This is a another screenshot of the diy-projector, bright isn,愒 it ?

Well, now the screen size is only 60", so it愀 very easy to get foold.

mathias

I尋 SORRY I WROTE WRONG !
THE DIY-PROJECTOR IS TO THE LEFT AND THE COMMERCIAL TO THE RIGHT !

ace3000_1

The reason the pro projector is brighter is a few reasons, 1 is a more refined light engine, 2 is because it has 3 lcds i beleive this gives us 3x the brightness as 3x 10% = 30% from source though i could be wrong on this and 4 maybe your optics are out, and 5 the lumens on pro projector bulbs are abit more then the cdm-t, not only that but you are not using a condenser in your setup and this will yeald u 2x the brightness atleast!. I think basically u cant compare a pro projector that has 3 lcd's to a diy projector that only has 1, the 3 lcd's do make a difference to the brightness, also if you wer to use the same lamp in both projectors then you would have a more acurate reading on weather the pro one is brighter then the diy projector, another reason the pro projector could be brighter in this case is the fact that lighting a 15inch area is spreading more light then in a pro one thats got its light fully condensed into a beam, trust me this makes a very big as i have tried it and use that kind of system in mine projectors hence a reason why i use small lcd's.

Trev

mathias

[QUOTE]

True I惴 not using a condensor, because you can愒 do that with a PAR-design the light is already condensed in the par reflector and it will never work with a condensor in a PAR-refector.

And Yes "lighting a 15inch area is spreading more light" but as you can see on the picture down to the left, I惴 using a 10 degrees PAR30 reflector that lighting up the same area as a 7" tft screen, so if you magnifi that picture it will be the same as a 7"-design.

And no a pro-lamp is not brighter than a HQI, the pro-lamp is only 130W compared to a 150W HQI.

mathias

Why I bring this up is because the two choices actully cost the same, so is it really worth the money to build a 7"-diy projector ?

ace3000_1

quote:

Why I bring this up is because the two choices actully cost the same, so is it really worth the money to build a 7"-diy projector ?

going on a price comparison of $400 for a bulb every 2000-3000hrs compared to a bulb price of $37 for every 12000hrs yess lol and for your info pro projectors bulbs are brighter hence the lifetime they have, they are tweeked to the maximum light outpput rather then life span, u could get the same light output as a cdm-t as the bulb u have but it would have a life span of roughly the same, and it would be an inconvinience for shop keepers to change a bulb ever 2-3k hrs so they exstend the bulbs life comprimising some of the light where as in projectors they tweak the bulb for a higher light output and have less life, not only that but a reflector in a pro projector is custom made for its light engine so its one hell of alot more eficient then just using a spherical reflector, i just sold a pro projector and beleive me a pro projectors light is brighter, retrofit your projector with a cdm-t and u will see the diff strait off.

Trev

ace3000_1

quote:

True I惴 not using a condensor, because you can愒 do that with a PAR-design the light is already condensed in the par reflector and it will never work with a condensor in a PAR-refector.

Take a look at stage lights they use 2 condensers to keep the beam intense and condensed on a parabolic reflector design, and with that reflector u have u can change the angle of the beam so u can use a condenser, try a peice of card board over the light to see the reflected angle for ajusting the beam angle.

Trev

mathias

quote:

Going on a price comparison of $400 for a bulb every 2000-3000hrs compared to a bulb price of $37 for every 12000hrs yess lol and for your info pro projectors bulbs are brighter hence the lifetime they have, they are tweeked to the maximum light outpput rather then life span.

A UHP-bulb is the same as a "xenon short arc-bulb" and they are not tweeked to get more bright light, they have shorter life because the distans between the electrodes is shorter, the arc-tube is smaller and a have a very high pressure. The only reason they use that types of bulb is that the arc is smaller and because it愀 smaller the arc will be more intensive than the HQI, but the total light output is about the same. Why do they want the arc smaller then ? It愀 because it愀 more easy to concentrate the light in a straigh beam to the 0.7" tft panel and the projector will be smaller. By the way new UHP-bulbs have a lifetime of 6000h.

mathias

quote:

Yes I know that they use condensers in stagelight, but the reason they do that is to get the light more even and as you can see on my pictures the screen is a little darker in the corners, and that will be better with condensers, but the brightness will be the same as before.

And I惴 pretty sure that the Pro projector will be much brighter than the 7"-diy projector even with a cdm-t bulb.
3 panel against 1.
Pro has microlenses, not avalible on a diy, give 2 times brightness.

ace3000_1

quote:

And I惴 pretty sure that the Pro projector will be much brighter than the 7"-diy projector even with a cdm-t bulb.

oh absolutly as they have a brighter bulb, how do i know this? cos for 1 they dont use any less then 25000lm and 2 ive contacted a indian company who i asked specs on a pro projector bulb, that was 250w and 45000lm with a lifetime of 3000hrs, now unless they are wrong wich i doubt they wouldnt know their product pro projector bulbs are brighter, ive even heard of 380w pro projector bulbs putting out 90000lumens, thats a big pluss for them, so its not only the 3 panel issue but its also their bulb, micro lenses im not sure your talking about maybe its your english but my understanding is a higher scratch and dig spec making the lens more acurate and basically just in a smaller package, to me i think peoples projectors should be brighter then what they are, most of the time things arent lined up properly and their light engine isnt at its full potentional, with that being said i plan to fix this on making pre made light engines available with the RIGHT lenses used for projection in a certian sized aplication, but i think weather you talk pro projectoirs or diy you both have pluss and minus points in each, to me id rather build then buy and i know mines cheaper to run then any pro projector out there on the planet for the same given running time, lumens i dont care about, its just the mesurement of light from the screen reflected back to the veiwer, the more lumens reflected the more ambiant light u can have and still view the image, the less lumens the less ambiant light u can have in the room to veiw, although there is a point where u can not have enough light and the image will look washed out and have bad colouring, i havnt made a projector yet thats had this problem and i dont plan to either, my projector i beleive is the first of its kind in the world being clear plexi in its size and i think thats somthing that makes it different from the pro ones, and thats what i like, somthing different, if i didnt care about diy or was lazy to build or wanted the easy way out then i would have bought a pro one like you have, but once again bulb prices and the cost of repair as manny of these cant be fixed by the average electronics enthusist, as for saying that mine will be darker then a pro projector where did i say it would be brighter then a pro projector? u cant exactly match a 3lcd with a brighter bulb with a single lcd with a less brighter bulb can we? i think the answer is obvious, however u may want to talk to cruser about his machine as his hits neary the 1000ansi lm mark just with 20000lm of source light, now to me thats better then a pro projectors efferts with 3 lcd's.

Trev

18wheeler

mathias

what's the brightness rate of your commercial projector?

mathias

quote:

u cant exactly match a 3lcd with a brighter bulb with a single lcd with a less brighter bulb can we?

I think you have missunderstood me a little, The comparement I did was to show how bright a cheap commercialprojector is with it愀 orginal bulb, because people beleve a diy-projector can be over 1000 ANSI-lumens bright with a 250W HQI bulb and that is far from true. With a 1000 ANSI-lumen projector you can watch movie on a screen size of 200" in daylight. I惴 not saying that the commercial-projector will be that bright with a cdm-t bulb, but I惴 saying that I think it will be brighter than a diy but not how much.

My commercialprojector is around 800 ANSI-lumen, and I think 400-800 ANSI-lumens is good for home-movie, but my contract rate is too low, it should be around 800:1 to be good. At the end of the bulbs life the output will only be around 400 ANSI-lumen and I think that is what I get if I change the bulb to a cdm-t.

Below is a explaning what microlenses are, and why they make the projector brighter, the picture belongs to EPSON.

ace3000_1

quote:

Below is a explaning what microlenses are, and why they make the projector brighter,

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

mathias

quote:

If i didnt care about diy or was lazy to build or wanted the easy way out then i would have bought a pro one like you have.

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.

Hezz

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

mathias

quote:

see no reason why you could not use a condenser lens with the PAR reflector.

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.

mathias

I think this is the link you are looking for.

Cut a par30-bulb

ace3000_1

quote:

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.

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

ace3000_1

quote:

I though Ace ment another type of condensors

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

ace3000_1

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

mathias

Thank you for some info on condensors.
The last design has a big problem and that is why I say it愀 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愀 a really bad solution, don愒 use it, it愀 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.

mathias

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%20Sh...ps%20UHP120.htm

mathias

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.

ace3000_1

quote:

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.

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

mathias

quote:

I my case the projected light was not dirrent than it was from the bulb, the fresnell didn愒 affect the whitecolor.

But one thing I know is that you don愒 notice the lower colortemp, if you don愒 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愒 loose much light with it, and it愀 probably not so very cheap to make one.

mathias

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愀 not stand in the way for the picture. This is why you can mount a com-projector in the roof, without touching the keystone.

mathias

Sorry, forgot the picture.

mathias

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愀 started, but the projector will be in warmup state, so I couldn愒 turn it off but I think it愀 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愀 level when the projectorlamp has warmed up. So what I惴 going to do is to measure all the wires and see which of them that change it愀 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 ?

ace3000_1

quote:

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

mathias

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愒 see one single pixels, so I really hope the 1024*768 projectors will get cheaper.

ace3000_1

quote:

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

mathias

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愒 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愒 take out the broken lamp from the reflector-module it愀 easy to build a new reflector with a small halogenrefector lamp. But be aware of that UHP-lamp can explode with great force.

slize

quote:

Originally posted by mathias
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愀 not stand in the way for the picture. This is why you can mount a com-projector in the roof, without touching the keystone.

hi mathias,

meanwhile it is even possible for diy-pj s to do keystone correction.

Duffy in the german diy forum posted a solution for that: i didn't try it it yet but it sounds logical and he also posted results and pics which showed that it works.

i posted the link

the site is in german, but i think the pictures speak for itself

http://web102.sun-15.de/forum/phpBB...opic.php?t=2361

18wheeler

http://www.diyaudio.com/forums/show...0731&highlight=

you can also tilt LCD for keystone correction, so light will hit groves of second fresnel in 90 degree angle and reduce the light loss.

mathias

quote:

it is even possible for diy-pj s to do keystone correction.

I know it愀 possible to do keystone correction in diy-pj, I read that a half year ago, but didn愒 mean keystonecorrection. Keystonecorrection is done by tilting the pj up or down, but this is the not the case with commercialprojectors, they are NOT tilted to get the result in the picture above.

ace3000_1

Mathias that idea is done with an offset lens, it can also be done with a mirror, no one has botherd with it cos its not somthing thats realy useful, the only use for that is maybe a roof mounted projector and kept strait so it can help keep a height from a persons head. Also on a table if you like your projector flat, but with that being said to get an image higher on the wall a projector doesnt need to be tilted very high to get a high image on the wall (unless u like watching stuff on the ceiling lol). So in regards to this type of offset image shifting no one realy bothers with it cos there is realy no use for it. keystone is the more usable option and what people are realy botherd about. I can garentee u that the later projectors dont have this as its an option thats not feasably used by any end user.

Trev

mathias

quote:

I can garentee u that the later projectors dont have this as its an option thats not feasably used by any end user.

I don愒 no what you mean with that, that is not an option, this type of offset is built in in all pro-projectors and you can not switch it off, when you mount the projector in the roof you mount it upside down, this offset thing makes it possible to not using keystone at all.

ace3000_1

quote:

this type of offset is built in in all pro-projectors

Mathias how manny projectors have u had? ive had 5, not one of them has this system, maybe only on your model it works the way it does, but on others most dont utilise this feature anymore, this is a feature mathias that is not encorported in ALL projectors anymore, simply to cut costs on somthing that is not practical to a HOME user. In my last post change option to feature because this is a feature weather u like it or not and its somthing u PAY FOR.

Trev

mathias

I don愒 know if we are talking about the same thing, I look like a questionmark right now ?
This features has been on all projectors I have seen, without it, you have to keystone 45 degrees if it愀 mounted in the roof. And in a classroom the picture should be 10 cm from the floor without this features and nobody could see the bottom of the picture because of the benchs.

ace3000_1

quote:

without it, you have to keystone 45 degrees if it愀 mounted in the roof.

LOL how high is the roof? 30ft? maybe the projectors u have seen with this are in short throw projectors, there is no way u tilt a projector 45deg and the keystone is what u use to correct it, tell me somthing, if this thing your talking about is so good and can project through benches while on the floor lol then why do they have keystone on a projector? i know the answer but do u?

Trev

mathias

quote:

if this thing your talking about is so good and can project through benches while on the floor lol then why do they have keystone on a projector?

:) yea that would be something, funny anyway.
I found a good link to the famous X1-projectors everybody is talking about, that explane the offset that all commercialprojectors allmost have.

http://www.infocus.com/service/x1/f...on=1&cat=offset

ace3000_1

Using image off set u can loose resolution, its ok if a 16:9 image on a 4:3 lcd but if its a 4:3 ratio lcd and u want to offset a 4:3 image then u will loose reso, the 7inch lilliput has the feature already so im lucky :)

The only way u will not loose reso is if the lcd is not using all of its area at one given time, this would mean that a 4:3 ratio lcd is not actually 4:3, it would be higher and wider then its active reso states, which means the lcd is not fully using its total active area at any 1 given time and the only area u are using is the reso of the projector.

An easier way of saying this is that the image on the lcd is actually smaller then the total active area of the lcd's capabilites.

Trev

ace3000_1

Its easy to do mathias on a diy projector, just shrink your image and move it around on the lcd's active area.

mathias

Trev, please read the X1 link, the offset has nothing to do with the resolution, they use the optics for the offset.

"An image offset of 100% means that all of the image is above the lens plane, with the bottom right at the lens plane" this is the offset I mean and all commercialprojector have this. DIY-projectors have 50% offset.

ace3000_1

quote:

What is image offset? The 'image offset' percentage for a projector tells you where the image will appear in relation to the plane of the lens. An image offset of 0 means that half of the image is above the lens plane and half is below. An image offset of 100% means that all of the image is above the lens plane, with the bottom right at the lens plane. An offset value of more than 100% means that the image appears a distance above the lens plane, or below the lens plane if the projector is mounted on the ceiling (pictured below).

It doesnt say anything about using optics to do this, and i was refering to diy projectors loosing reso. This cant be automatic, the projector has to be told in some way where the image is to go, ie a button or a switch to move somthing, either a lens, mirror or the image. As i stated in a last post that its either the lcd image shifted, a lens being offset, or done by a mirror.

Trev

mathias

To explain easy the difference how the picture is projected in a Commercialprojector and in a DIY-projector is like this:

The commercial is projecting the whole picture over the objectlens height. DIY-projectors is projecting the half picture over and the the other half under the objectlens height.

This kind of default offset is done in commercialprojectors with optics like lenses or mirrors, and I hope someone can think out how this work, because I promise you, that you want that in your diy-projector.

ace3000_1

Thats easy, offset the frensel, thats all there is to it. It will bring the image plane over the center of the lens. This will take a wide feild of veiw lens though.

Trev

mathias

I have posted a solution of the diy-offset problem in this link, it愀 maybe what you mean Trev.
http://www.diyaudio.com/forums/show...&threadid=20731

ace3000_1

Nope not at all, the frensel lens is cut offset, the mirror has to be also cut offset to compensate the shift, i fooled around with this in small amounts on mine, not on purpose but because the lcd is not centerd in its frame, thats how i know this, also in an infocus i had it utilised a similar system where the light engine and the frensel wer both offset, but we can actually make it so the light is still strait and only the image is offset. its not as hard as u think to acheive this.

Trev

mathias

quote:

its not as hard as u think to acheive this

I don愒 think this is a hard thing to do, infact it愀 very easy, and there are maybe many ways to do this.
But I only want people to know that this features is a very nice thing to have in a diy-projector as a default setting, it solve many placing problem.

thrombose

quote:

Originally posted by mathias
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.

Mathias,
Seems like a great idea. Have you had any success on changing the bulb? I searched on the net (UHP bulb replacement), but I get the 400$ lamp UHP replacement results. Would you have a link or any ideas on search terms on where to get that small lamp, or a specialty store that may carry them?

Found this old thread
http://www.diyaudio.com/forums/show...&threadid=10894
Though it isn't exactly the same as what you mentionned...

mathias

This is the information I know today: A UHP-lamp is a Ultra High pressure mercury arc-lamp manufactured by Philips, UHM is the same type of lamp but manufactured by Matsushita and the P-VIP is also the same but from Osram. This type of lamps are not the same as a xenon short arc bulb that I sad before, UHP lamps use mercury gas instead of xenon and they have higher voltage but lower current than xenon lamps. UHP-lamps have a arc length of 1mm against 9mm of a cdm-t lamp. Most new UHP-lamps are driven on DC-voltage and use a DC-voltage ballast, HQI-lamps can not run on DC-voltage, so don愒 try to connect a HQI-lamp to the built in ballast.

The lampmodule reflector can be of parabolic or eliptical type, most common is the parabolic, I have that in my projector.

The company Ushio is in 99% of the case the supplier to these UHP-lamps.
http://www.ushio.com

The problem is as usually that most companies don愒 sell this type of bulb to end-users, so if anyone can find a company that sells this type of bulbs, please let me know. If you want to make money, start a company that sells this UHP-lamps cheap and I promise you that you will be rich !

If we can愒 find a supplier of this lamps, the cdm-t bulb will be a cheap choice, but needs some optics to work and a ballast.

More and more people are interesting in this because the price on a UHP-lampmodule is a bad joke.

Anyway I haven愒 got time with this now, but I will do more research before the summer.

mathias

I have done little more research now and I have found out that it愀 impossible to find a cheap uhp-bulb that can be placed in the old uhp-reflector-module, they just don愒 sell them. Not to mention that the uhp-bulbs can explode just by looking on them.

More interesting is that the price of different uhp-lamp-modules vary with over 2.5 times the cheapest lamp. This opens new opportunities, if you know the wattages, voltage and the shape of your old lamp, there are big chances that you can find a cheaper lamp-module and change the "reflector-lamp" and place that in the old plastic-cover. There are many projector-modules that use the same "uhp-lamp-reflector", they have only different platic-cover and then they charge 2 times the price for the same lamp, I think this is a damn bad way to fool people.

mathias

Here are my lastest thoughts about puting a HQI-lamp in a commercialprojector. The biggest problem with this is that a HQI-lamp is very big compared with a uhp-lamp and a big lamp with a large arc need a big reflector to use all the light from the lamp. The smallest lamp available to normal users is the HTI 150W lamp with an arc size of 4-5mm but it only last in 750h and is not so cheap and it愀 still to big. To place a big HQI-lamp with a big reflector in a small commercialprojector is not so very easy (impossible) and if you make changes to the case it愀 hard to sell the projector later if you want to do that.

I think the best solution is to use a separete lightbox with fans and use fiberoptics to led the light to the projector. In this way you can use what type of HQI-lamp you want and you don愒 have to worry about the heat.

I have done some tests with fiberoptics and it works very good, but we need a thick fiber or many fibers because it愀 hard to concentrate the light from a HQI-lamp to a small fiber.

mathias

I forgot to mention what I mean with short focus positive lens on the lamp side. The incoming light must have smaller angles than 45 degrees from the fiber axle, otherwise the light will not follow the opticalfiber and you will lose a big part of the light. So the lens must have a focus length that is more than the half size of the lens or reflector size.

Hezz

This is an interesting idea Mathias.

I see no reason why it would not work in theory. I think fiberoptic cable would be to hard to work with unless they make it in large sizes. Because the angle of incedence of the light inside the tube is so high there can be high reflectance even for a white plastic tube. Yet it seems that it would be so much more efficient if you could get a highly reflective smooth surfaced flexible tube of around 20 - 30 mm size.

I have seen some white plastic tubing that is semi flexible but still hard enough to have a shiny surface finish used for some kinds of lab plumbing. I wonder if that would work.

Also because of the light loss it might be wise to oversize the light source but because it is in a seperate box it does not have to be so small. You could use a large cheap industrial 400 watt metal halide and a large reflector and a hand made large lens to focus the light into the optic tube guide.

The straighter the optic tube is the better as there is less light loss.

One other idea is to use electrical conduit and run some kind of lapping material through the inside to polish it up. Also, though it is expensive there is stainless steel tubing available and it could be polished on the inside to a high luster with a rotating lap turned with a drill.

Hezz

carozoynarizota

quote:

Originally posted by mathias
...if you know the wattages, voltage and the shape of your old lamp, there are big chances that you can find a cheaper lamp-module and change the "reflector-lamp" and place that in the old plastic-cover. There are many projector-modules that use the same "uhp-lamp-reflector", they have only different platic-cover and then they charge 2 times the price for the same lamp, I think this is a damn bad way to fool people....

I want to adapt an HQI lamp to my EPSON ELP-3000 projector (wich is equal to Infocus LP580).

The original lamp says it is Metal Halide 150W and 65V. Does anyone knows about commerial lamps with this characteristics, you can find many of them with 150W, but I never see on its specs that they where 65V (the ones I know use for example 90V).

If I get one matching the specs, Is it dangerous to power it from the original ballast? Or another 150W 65V doesn愒 mean that the lamp can be equally powered?

Thanks

Tiarb

Hi!

I just read through this thread (again in a long time) and as I've been lately very active with my own projector retrofitting I think might have few things to add or to verify on these matters.

First of all the thing why I started to write this post was to criticize about the comments that projectors with 3 panels would produce more light compared to a 1 panel one, even 3x, that is not the true, the benefits of 3 panels lie in totally different things.

The brightness matter is pretty simple to explane. As the light for the three panels has to be splitted in three 1/3 bits (and the splitting is something that also definetly generates some light loss, in my projector it's been made with two mirrors that let light trough as well as mirror it, and also few regular mirrors), each panel gets at most the 1/3 of the initial lightengine output, and each panel has its own color filter, red, green and blue, and they effectively remove all other light but those mentioned. That means that of the 1/3 that has been directed for the one of the lcd's there will be something like 2/3 filtered out also in that point. I find it hard to believe this kind of stuff would then let trough significantly more light then a single panel setup lets. It might even be worse then 1 panel setup in that aspect.

Ok... so to the small benefits of the 3 panel setup that I can think of... well, the pixels do not consist of small 3 different colored parts as red, green and blue pixels can be projected over each other making the actual pixel really that color that its supposed to be... Hehe... that benefit is only useful if you look your movies at distance of 0,5m or something... ok... Other benefit would be that the cooling of the LCD's is easier as the do not heat up that much, the color filter is the reason for that, it filters out most of the unwanted stuff. And of course I'd guess the high resolution smaller than 1" grayscale panels are definetly lot cheaper the the color one for the same resolution and same size, this might even be the real reason for them to even exist...?

I've been discussing my project on several threads but I guess as this thread is all about what I am actually doing then it probably would be good to tell about my findings in the matter.

I have cheap 3 panel Sony projector (market price for a used one is something like 500e with a spare bulb...), the original light source was 120w UHP lamp, pretty much same kind that has been seen on this thread before. And as has been mentioned on this thread, retrofitting the projector so that it's in it's original case is very hard, it's almost impossible. I tried halogens first (that setup actually fitted inside the original case!!!!) but they were so hot and yellow that it was clear that they are not something that can be used in a projector retrofit, at least if the bulb is going to be somewhere where the original bulb was. I used the halogen with a diaprojectors lightengine setup (they beam out quite paraller light beam if the flame is positioned right, and work pretty well even if the flame is a bit off) and the 250w halogen broke all the lenses and burned the frame to coal... and yes, I had two 8cm fans blowing on full throttle all the time straight on the lamp and the optics, I even cut all the original case that was possible to cut away without the thingie fall apart to be able to try ways fo better airflow.

I got a 150w HSI-TD/NDL metalhalide bulb (same as HQI) and ballast about a month a go and have been experimenting with it since. TD means it's double ended one so it has quite a huge flame, but it does work! I've been using it with a BROKEN fat diaprojector condenser lens and the result is ok, original brightness of the projector was 500 ANSI lumens, I think with just the condenser lens (no reflector) I got something like 50-60% of that (comfortably visible in day time with dark curtains on windows (not totally light blocking ones)). I tried somewhat spherical soupladle behind it and other stuff as a reflector on multiple angles and got no visible gain in brightness... that is probably because of the huge flame (something like 10mm). Few days a go I bought another used diaprojector lightengine setup (as the halogens totally destroyed the first one) for 20 euros from one service center, I picked one that had a bigger reflector (so it should work better with the big flame of the MH bulb) and of course it has lenses that aren't broken and a UV-filter, and I get now a bit more better results, the image is something like 70% of the original brightness. I attached image of the setup with the bulb also in it's place. I am going to get single ended bulb with a smaller flame to take more advantage of the reflector later on (when I can afford it...).

I'll keep on experimenting with the bulb position and try how it works if I remove the last lense, and such stuff I can come up with, and keep you updated if I learn something worth telling.

Regards
HB

Tiarb

I did some testing with the lightengine...

When I first got the new diaprojector lightengine I didnt try it out of my projector, I just put it into the projector in a way that it worked. Today I took some of the projector apart for another reason but I also decided to research the light engine bit more.

First I tried it as it was, just testing how the position of the lamp affects the beam... well.. the thing seems to pretty much project image of the flame :B Position made it bigger and smaller... Then I took the second condenser lense (the thin last one in the setup) away and now the beam was much more even, although it still was a bit flame imageish but not that much, and actually it looked a lot more like the beam of the original UHP lamp. Then I tested the thing without the spherical reflector... not a difference to see with human eyes... I slipped the reflector back in its place and all that it did was that it added round thingies around the beam. I think I can't get any more light with this reflector, it should be bigger one and so on, just like mathias has told. The flame is just so big compared to the reflector that it just doesnt do anything, and the outer glass of the bulb is so big too that I cannot get the flame as close to the reflector for it to work well, and sadly, the outer glass is about the same size on those single ended bulbs too :\

I think that the best option, if we dont want to use big reflectors and bigger external light boxes and light guides and such, is to just use the light that comes straight forward from the lamp. It means that there is quite a big light loss but what can you do :(
Many people use 250w MHs on their projects, I use 150w one and with this method I get very well viewable resultss, ok to use even in daylight with somewhat thick curtains on, so I am pretty sure that a projector retrofitted with 250w MH using this method should get pretty good results, probably even a lot like with the original 120w UHP lamps.

Regards
HB

denun

btw i have no space and not knowledge to build a projector myself, so i'd like to modify a commercial projector.

the new panasonic AE700 has all the features that i need, but it's only 1000 ansi lumen.

i tried different projector in my home from 800 ansi to 3000 ansi, and when u see the difference u'll say "WOW" instead when u see the different cost u'll say "OUCH!" :D :D

So, this panasonic is amazing, and the price is affordable (~ 2000$), now i'd like to ask u if i'll buy this projector is there any chance to take 2/3000 ansi lumen from that (having 1000$ of budget)?

Tiarb

quote:

Originally posted by denun
btw i have no space and not knowledge to build a projector myself, so i'd like to modify a commercial projector.
So, this panasonic is amazing, and the price is affordable (~ 2000$), now i'd like to ask u if i'll buy this projector is there any chance to take 2/3000 ansi lumen from that (having 1000$ of budget)?

Um... I'd say pretty much NO... Maybe if you'd retrofit it with 1000+W MH halide it might be possible. Or maybe if some totally excellent engineer that has specialized in light sources might be able to do that with bulb that has less power, but then there has to be perfectly perfect optics that are perfect in a perfectly perfect way (read: EXPENSIVE and HIGH TECH). The projector loses easily 90% of the light in projector's optics. Your 1000 lumen projector is very likely to have a 15000-20000 lumen lightsource with perfect optics. 4 example my projector shooted 500 ANSI lumens with the original about 10000 lumen lightsource and it's perfect optics and now that I have self made cheap 11000 lumen lightsource the end result is something like 300-400 ANSI lumens :P The original lamp costs 400-500 euros, the retrofit one about 40 euros... that's the main reason to retrofit a projector that is over 500 ANSI. Of course some really old lousy ones with halogens and such crappy lightsources to begin with might be better after retrofitting.

Also I might add that most of the diy projects and retrofits on this forum are very very very very likely to be something like 1000 ANSI lumens maximum in the end, even those with 400w bulbs. So... if you want brighter than that (which is IMHO veeeeryyyy weird as 1000 ANSI lumens is so bright that you can have very very bright 60-80" image with thin curtains on bright day or with no curtains on cloudy day) then stick with the commercial projectors. Also... as I said its a bit weird not to be satisfied with 1000 ANSI lumens, I'd check if the optics on the 1000 ANSI lumen projector are covered with dust or some powersaving mode on or something making it dimmer then it should be :\

Regards
HB

Andres

Has anyone given any more thought to this posibility (mathias, ace?)? I've researched and it doesnt seem impossible to build the illuminator for the fiber optic pipe. Here's the link to a diagram I found of what it sould look like.
www.lot-oriel.com/pdf_uk/all/light_fiber.pdf

Of course, I have 1/100th of the knowledge of optics you guys have so I might be oversimplifying things.
Light guides can be found on ebay for not that much money.

Any thoughts? Has the idea been dropped completely?

Andres

http://www.labx.com/v2/newad.cfm?CatID=41&Page=2

Maybe we can retroffit one of these? Some go for $50 with a 150W Quartz-Halogen lamp.

misopr

Hallo, I have sharp xv 310P projector but withouth lamp.
don't anybody know how to make lamp for this projector? I haven't also the cage for the bulb. It has 150w bulb. thank you

misopr

AND the pic of projector

Tekko

mathias, could i have the original lamp if you do the MH lamp reterofit ? Now i don愒 have a ballast but it shouldent be a big deal fixing one

misopr

do anyone know how many volts bulb fits sharp vx 310P (P10U) projector?

Luca Brazzi

quote:

Ahem....

If I may be so bold...

But...

I think that the theme of this thread misses one vital point...

Why DO people Build a DIY Projector?

Well let me put it this way...

About 3 years ago, I started learning to play Guitar...

Now... Why would I do That?

After all... I could just go out and BUY the works of the greatest Guitarists of all time for alot cheaper!

Do It Yourselfers/Engineers (like me) get a rush from researching, designing, and building. For the true DIYer/Engineer, there are no shortcuts.

And thats the name of THAT tune!

I just thought I would throw that one in...

Continue...

mathias

Yes, you have absolutely right, but buildning a DIY Projector the normal way, is a really expensive hobby in proportion to what you get today. The thing I am writing about in this thread is still DIY but in an other way.

As a true DIYer/Engineer, with limit economy, I can only say DIY-parts cost more money than everbody think and don愒 forget the freight charge. My DIY-projector hobby have been resting a year now and holy **** what money I have saved. The sad truth about many DIY stuff, I can愒 help it, it愀 just the way it is.:bawling:

Today a DLP-projector is so cheap and have so much better performance than a lcd DIY-projector. Why build something worse and more expensive, when you instead can modify a better performance dlp-projector with the stuff we DIYers really can do (the lightsource and lightengine) ?

Arnold_the_cat

Hi, I have been reading this thread with interest. I have recently acquired a 3M 8620 projector. The projector requires a 400W Metal Halide lamp. No new electronics are reqired, it is just a case of slotting a new lamp into the old ones place. However, the new lamps are still hugely expensive. Is there any reason why i can't buy a cheap metal halide bulb with similar specs from ebay or cheap retailer? Thanks in advance for any advice/information you may have.

fiak

For misopr and arnold the cat.
I searched a lot and realized that you cannot find cheap
lamps for projectors and it is also almost impossible to use
anything else.
The cheapest solution I found is to replace the lamp (usualy comes with the reflector), from
the lamp module and that only from:

http://www.mijnwinkel.nl/shop13342/productlist8/

Check the (lamp only) configurations, as these come at about
half the price of the unit.
misopr you must find the lamp unit. :clown:

elbozze

check this link

http://home.arcor.de/elektronikschrott/DIY/InFocus.htm

irdaze

I have been messing about & came up with this to start with

not that bright but its a start - 75w 240v (so no need for a transformer)

am now trying to locate a 150w bulb (quite difficult)

any ideas?

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