gaming247 said:
It really depends on the type of antiglare and the Lcd. But it probably averages out to about 10%
phutton said:
If "one of the LL members" measured 430lm light output of this kind of projector, unless he used a 1000W short-arc bulb, it was probably a "commercial advertisement" , or in other words a scam. The trick is that once I calculated max theoretical light output of such projector, assuming 400W bulb, 100% efficient reflector, optimal precondensor, standard LL projection lens, 10% transmissive LCD, and no extra loss in glass layers and plastic fresnels. It was about 280lm, with these absolutely unrealistic assumptions. So in reality you can get less then 200lm, most will average at 100-150lm.
And, if you want to know the truth, ask that guy to post you pictures of the screen, with full EXIF info and info on screen size. You will see exposure time like 1-2s at ISO100 and screen 2m wide, or something like that. Would it be really over 400lm, then the screen would be bright like in the real cinema, and you could take pictures with shutter speed much below 1s, more like 0.1-0.2s. No one has presented such pictures yet, as no one can overcome physical principles.
About using a bulb from a commercial projector for our 7-17" LCDs - you don't understand principles, you simply cannot use these bulbs, they are integrated with an reflector, and focused for tiny 1-2" LCD. And if you don't understand principles, you are under risk of being fooled by such "advertisers" like the one with "430lm DIY projector". Anyway, if you could take a bare bulb out of the reflector, your benefits would be none, as nowadays projectors use relatively low power bulbs, in the range of 120-150W, so replacing your 400W bulb with a 150W one, even if there would be some benefit of short arc, would overally lower total lumen output. Despite that, you can actually buy a relatively cheap short arc 150W bulb, look at the threads here, so why do people who initially built their boxes with a 250W bulbs soon look how to replace it with a 400W bulbs?
Regards
pepe303 said:
Did you ever think that those settings might be camera specific. With my 6 year old digital camera I have tried to take a pic at several cinemas and I couldn't get a good pic without a 1.5-2 sec exposure time.
hailrazer said:
Did you ever think, that thousands people around the world have built projectors based on the same concept, and no one of them, who appears realiable and knowledgeable, has yet reported that high brightness? There are some "reports" apparently from dummies, who claim "my projector looks like a 1000lm one". All reliable measurements yield results in the range 50-150lm. Did you ask that inventor what exceptional he did to obtain his 400lm? Or you just assumed it's true, because you don't have enough knowledge to ask more specific questions? Sorry, but this is obvious, when I hear something hardly believable, I don't shout "wow, amazing, good for you!", but I would rather ask about the details. And for some reason, the area of DIY projectors is crowded by scammers. 150" TV made with a page magnifier, 1000lm projector, "pro quality" with a dismantled cheap LCD and surplus OHP lenses, and so on..
Now I see on LL someone announced magic bulbs, that are cold (100% efficient?), and don't require any ballast. And people get involved in this subject, no one tells him just "get away scammer".
Regards
They shouldn't be, and it's a reasonable way of comparing illuminance, but you need to know the effective aperture of the camera lens too.
Well I have 2 different digital cameras and at the exact same settings they produce 2 entirely different results.
But hey I guess if Pepe is going to believe that all cameras are equal and all DIY projectors are equal, who ame I to argue.
But hey I guess if Pepe is going to believe that all cameras are equal and all DIY projectors are equal, who ame I to argue.
pepe303 said:
my wife's grandfather built their first television with no more education than what he learned in the navy. that was probably 40 to 50 years ago. i'm also sure that the first refrigerator was a hands on process. factories don't just magically start producing new ideas. drawings must be made. prototypes must be built. i think a diy refrigerator would be relatively easy to build compared to the guy/guys that first built and rebuilt one through trial and error. they did all the hard work. we just need parts. it's safe to say that if you use inferior parts, you get inferior results. there IS a solution to the brightness problem. mainly cost, i would assume. give it TIME. in twenty years, VHS will be obsolete. CD's will be looked at like 8 tracks. they will re-reinvent the wheel...again. in a lab, somewhere someone right now may be working on something that will send lcds packing. what seems out of reach at this moment will certainly be attainable to those who are patient. and in five years, when i've grown accustomed to my not-as bright-as-i-would-like projector, someone will have the solution i was looking for- cheap. i'll swap the old bulb and ballast out for the Mega Lumens 3000 that lights the whole room up and then decide i liked watching movies much more in the dark.
um... I have worked in high end home video/audio for about 6 years now. The cheapest projection tv we sell is 2500 dollars and the most expensive is right around 68000. So, My boss built a wxga projector, final cost at about 800 dollars. It is large, it is not loud, it is watchable in ambient lite in our store, and to me it has more brilliant colors than most tv's in the store. The screen is larger, it takes way less upkeep, it doesnt look washed out like every other pos projector in our store, and it cam with lots of injinuity and pride from the owner. My uncle heard I was building a projector and offered to by me one from the store. Lets just say it would be more than 1300 dollars off. Sure it would be brighter, it would be smaller, BUT IT WOULD ALSO BE EXTREMEMLY BORING. Dude Ill be building all my own stuff until i can no longer physically do it, because it is fun and it tries the mind, your theoretical crap can sit in the back of the class like all the other book nerds, while those of us with capable hands and better thinking minds can go and prove why your *theories* are just that.
Also, my physics teacher who studies laser refraction came up with a theoretical maximum of 2700 lumens from a 33000 lumen lamp. They actually took a faculty(lame professors club) meeting and discussed it. He was intrigued when i brought in a prototype to show him the fresnels i bought. He then pointed and laughed and told me If I could figure out his math he will show me how to do it with fiber :O
To the original poster, you could be the one to tell all of us how to get it brighter. I am in the same boat as you, and everyone else seems to be perfectly happy with just a movie room, but I wanna use my projector all the time. Sorry I can be no more help, but I will let you know as soon as I figure it out.
by the way pepe 300 years ago people EXACTLY LIKE YOU used to tell all the "morons" that the world was flat. 60 years ago people EXACTLY LIKE YOU said splitting the atom was beyond the realm of the physical world. Wow... thank god your not pushin science, and if you are... well retire please.
Also, my physics teacher who studies laser refraction came up with a theoretical maximum of 2700 lumens from a 33000 lumen lamp. They actually took a faculty(lame professors club) meeting and discussed it. He was intrigued when i brought in a prototype to show him the fresnels i bought. He then pointed and laughed and told me If I could figure out his math he will show me how to do it with fiber :O
To the original poster, you could be the one to tell all of us how to get it brighter. I am in the same boat as you, and everyone else seems to be perfectly happy with just a movie room, but I wanna use my projector all the time. Sorry I can be no more help, but I will let you know as soon as I figure it out.
by the way pepe 300 years ago people EXACTLY LIKE YOU used to tell all the "morons" that the world was flat. 60 years ago people EXACTLY LIKE YOU said splitting the atom was beyond the realm of the physical world. Wow... thank god your not pushin science, and if you are... well retire please.
Actually, I seriously considered going with the Philps CRM-short arc 150Watt bulb. It puts out 12900 lumens with an arclength of 6mm and a lifetime of 6000 hrs. However, when I did the calcs for using this with a precondenser, Pro reflector, and antiglare removed lcd I only got a max output of 297 lumens. This is not bad, but it is only a slight increase over my current setup, and significantly lower than a redesign using my current 400 watt system. It just didn't justify the investment in a new lighting system.
You will be benefitted by viewing our design. The details can be seen by clicking the following link to our web page:-
http://www.drstsolutions.com/Projector.htm
http://www.drstsolutions.com/Projector.htm
Camman said:
Ask your teacher about details. Guys, whenever you hear about such exciting findings, you should always ask about details, even just out of a pure curiosity, to learn and understand more. Yes, there would be possible to get 2700 lumens out of a projector with a 400W bulb. Just take out the LCD and you will have your bright 2700lm projector.
And your assumption that there is some yet unknown science, which one day will be uncovered and will allow us to build bright projectors with dismantled desktop LCDs, parking lot bulbs and kitchen utensils, this assumption is basically wrong. This "undiscovered" science has already been worked out, and the result is that this kind of "technology" was abandoned by projector manufacturers, as this is highly limited and inefficient. Now they use either 3 LCD panels and colour splitting mirrors, or DLP chips. Small bulbs with integrated elliptical or parabolic reflectors, and lens of optical grade (not plastic page magnifiers and recycled OHP stuff). And it's very unlikely that one day you will find such components in some trashed home or garage stuff, or discover these parts lying around in hardware stores, and build cheap, quality projector out of it.
Regards
The quality of projected image in a DIY LCD Projetor is to be compared in the realm of DIY LCD Projectors and not commercial LCD Projectors. With suitable softwares, one can get even better images vide pictures contained in the following link:-
http://www.lumenlab.com/forums/index.php?showtopic=5141
Making a DIY Projector is part of make or buy decision when one can have slightly inferior images at 20% of the cost and with the software as above even the images could be superior. Other plus points are longer lamp life, cheaper lamp assembly, longer LCD life. Our projector was viewed by a theatre owner as well as a distributor of commercial projectors, both were quite impressed.
http://www.lumenlab.com/forums/index.php?showtopic=5141
Making a DIY Projector is part of make or buy decision when one can have slightly inferior images at 20% of the cost and with the software as above even the images could be superior. Other plus points are longer lamp life, cheaper lamp assembly, longer LCD life. Our projector was viewed by a theatre owner as well as a distributor of commercial projectors, both were quite impressed.
believe me I asked, i gotta figure it out. I never said there would be an undiscoverd 'science'. Believe me I know the limits, but for you to say the brightest home made projector has been built using common components, you know what they say about opinions. I am just saying i disagree. This is all about experimenting and building with nothing more than common parts and your mind. Its supposed to be fun, and I dont think we have even come close to the brightness barrier.
ramkishan said:
There is no software that can improve poor hardware, and the weakness of DIY projector is within the hardware. The guy from the link you posted above did not build exceptional projector, he made exceptionally good pictures. The trick is to set brightness, contrast, gamma correction to make all the details visible to the camera. For human eye, these images would look dim and dull, but you can "compensate" it in pictures, setting night mode, long exposure, and using quality camera (the one that generates little noise for long exposures and high sensitivity).
Besides that, devoting a brand-new, powerful PC to a "home theater" makes the overall cost skyrocket, and it's generally a crappy solution. Instead of a small, slick, quiet and cheap DVD player you have a big, sometimes noisy, power-hungry and problematic PC. Think about energy waste, this setup will consume about 600W, just the projector and PC, not including audio components. I know there are some countries where energy is still funny cheap (or real costs are cleverly externalized), but that's a whol another issue, not suitable for this forum, but should be taken into consideration.
Regards
The hardware of DIY LCD can not be compared with that of commercial projecors as both are entirely different technologies. the HTPC described in the link is not expensive. The cost of extra energy is much lower than the cost of investment in the commercial projector and hence it is not a waste. The DIY forum is for such home made projects and not mass produced high technological and expensive goods
hello pepe, long time.
I know who that member from lumenlab has been mentioned here... I will let him know asap that he has beenmentioned here.. then if he wants, he will decide to post here or not.
Now what I can say about;
you have critisiced him with no idea about his setup, he has posted several photos, and also owns a luxmeter, rare on diyers. This obiously implies he is more implied on the building than most of builders.
some interesting data for your calcs (by the way, would be interested checking them);
*40Klumens 400W lamp.
*pro reflector (yea I know you don´t like the name, but I don´t like your name either but never said nothing about it)
*220/650 fresnells
*pro triplet (500mm focal/100mm clear lens aperture)
*17" TFT, 8.8% trasmisive (luxmeter test) no antiglare removed as has been errorneusly said.
He meassured 5000 lumens with no LCD on the way, and somewhere 430lumens is the MAX ansi lumens he could meassure.
you move
I know who that member from lumenlab has been mentioned here... I will let him know asap that he has beenmentioned here.. then if he wants, he will decide to post here or not.
Now what I can say about;
you have critisiced him with no idea about his setup, he has posted several photos, and also owns a luxmeter, rare on diyers. This obiously implies he is more implied on the building than most of builders.
some interesting data for your calcs (by the way, would be interested checking them);
*40Klumens 400W lamp.
*pro reflector (yea I know you don´t like the name, but I don´t like your name either but never said nothing about it)
*220/650 fresnells
*pro triplet (500mm focal/100mm clear lens aperture)
*17" TFT, 8.8% trasmisive (luxmeter test) no antiglare removed as has been errorneusly said.
He meassured 5000 lumens with no LCD on the way, and somewhere 430lumens is the MAX ansi lumens he could meassure.
you move
Rox: I don't want to make my calculations again on your request, as you always request something that is time consuming, and then when you realize it's more or less correct, you say like "but I did mean something different", like was in case of our discusion on precondensor lens.
Just think how it would be possible to get 5000lm from that projector without LCD, no complex math is really required. How much light of those 40k lumens hit the collector fresnell, not more than 20% for sure even with that "pro" reflector, so 8000lm. You loose about 10% in both fresnels, so you have 7300lm left. Now how much of this will pass the "pro" projection lens with f number like f/5? Do you know what f-stop means?
Regards
Just think how it would be possible to get 5000lm from that projector without LCD, no complex math is really required. How much light of those 40k lumens hit the collector fresnell, not more than 20% for sure even with that "pro" reflector, so 8000lm. You loose about 10% in both fresnels, so you have 7300lm left. Now how much of this will pass the "pro" projection lens with f number like f/5? Do you know what f-stop means?
Regards
yes I know what F stop means. In fact, the LL pro lens is very familiar to me.
well, the rough calcs you've just done are wrong. When I ask for checking calcs, is just for personal interest how people does things... tipically when i do calcs, I always start with initial assumtions (or axioms) there could be an error on calcs (im human) but n way to discuss the axioms, the axioms are not discussable since I state them. I mean the axioms are arguevable and improvable... but the maths should macht that axioms I stated.
Now, I will not force you to most your maths, but just saiyng it is no way for 5000 lumens is not cientifically aceptable.
well, the rough calcs you've just done are wrong. When I ask for checking calcs, is just for personal interest how people does things... tipically when i do calcs, I always start with initial assumtions (or axioms) there could be an error on calcs (im human) but n way to discuss the axioms, the axioms are not discussable since I state them. I mean the axioms are arguevable and improvable... but the maths should macht that axioms I stated.
Now, I will not force you to most your maths, but just saiyng it is no way for 5000 lumens is not cientifically aceptable.
Rox: you are right, my rough calculations are quite off, for simplicity I assumed that you can collect 20% of light output, while in reality it's more like 13-15%, and influence of that reflector (no matter "pro" or not) is almost neglectable. The exact calculations are not that simple to do it instantaneously, I just remember final results.
But for that simplicity let's assume we can grab 8000lm at the LCD, and LCD is removed. So my question again, how do you obtain 5000lm output from the lens with f-stop around f/5 and 8000lm input?
Regards
But for that simplicity let's assume we can grab 8000lm at the LCD, and LCD is removed. So my question again, how do you obtain 5000lm output from the lens with f-stop around f/5 and 8000lm input?
Regards
think easy; using a luxmeter at the projection screen 😀
this is a real test done by the owner.
and for your interest, the PRO reflector was measured to have 50% light increase (with/without), the best I heard before was the polished ikea giving near 25% increase).
and the 14% collecting... any further information to prove this?...
this is a real test done by the owner.
and for your interest, the PRO reflector was measured to have 50% light increase (with/without), the best I heard before was the polished ikea giving near 25% increase).
and the 14% collecting... any further information to prove this?...
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