hi gitesh
all your advices made me think a lot.
i have decided to go with MH 250watt only after doing a lot of search on net and experiments with 35w/35w motorcycle bulb.
second, I used my mobile( 1.8" LCD) to project on screen and found that image is small, not more than 29". so i have to use bigger LCD.
i had used miyota 5" (which i had screwed up few months ago). my TV lens accepts that. so will go with 5" LCD with TV lens. if it doesn't work, will use fresnel with triplet ( i already have both).
third, i tried to remove antiglare film from my scrap LCD but couldn't do it, so i won't try it on my new LCD
i had few questions
1) what did you do for blocking UV and IR? is that float glass enough?
2) if i am getting a condenser lens, how do i decide lens what focal length to be use? and basically will it make a huge difference, like being able to use 150W MH? it is available at lensel optics in various focal lengths.
3) i saw 3 fans in your design, is that enough or i need to use heat sink?
all your advices made me think a lot.
i have decided to go with MH 250watt only after doing a lot of search on net and experiments with 35w/35w motorcycle bulb.
second, I used my mobile( 1.8" LCD) to project on screen and found that image is small, not more than 29". so i have to use bigger LCD.
i had used miyota 5" (which i had screwed up few months ago). my TV lens accepts that. so will go with 5" LCD with TV lens. if it doesn't work, will use fresnel with triplet ( i already have both).
third, i tried to remove antiglare film from my scrap LCD but couldn't do it, so i won't try it on my new LCD
i had few questions
1) what did you do for blocking UV and IR? is that float glass enough?
2) if i am getting a condenser lens, how do i decide lens what focal length to be use? and basically will it make a huge difference, like being able to use 150W MH? it is available at lensel optics in various focal lengths.
3) i saw 3 fans in your design, is that enough or i need to use heat sink?
Re: hi gitesh
Hi ,thanks for taking my advice,
1)I used 10mm float glass covered with cling wrap. ( transparent plastic film that is used to cover food stuff )
2)I dont have experience with condenser lens. Lot of people in lumenlab have used it so copy that design. Better use 250w. I felt 150 w not adequate.
3) 3 fans are sufficient. I have an digital thermometer with my projector. temperature is always below 35 degree Celsius. Keep a large air inlet with air filters (use bike air filter or the one that is used with air conditioners)
By the way i use my projector approx 8 hours a week since i made it. It is a great source of fun for me , my friends & family.
Yesterday saw the movies forrest gump (i am watching it for the 3 rd time
) and alien vs predator 
with friends.
jaudere said:
Hi ,thanks for taking my advice,
1)I used 10mm float glass covered with cling wrap. ( transparent plastic film that is used to cover food stuff )
2)I dont have experience with condenser lens. Lot of people in lumenlab have used it so copy that design. Better use 250w. I felt 150 w not adequate.
3) 3 fans are sufficient. I have an digital thermometer with my projector. temperature is always below 35 degree Celsius. Keep a large air inlet with air filters (use bike air filter or the one that is used with air conditioners)
By the way i use my projector approx 8 hours a week since i made it. It is a great source of fun for me , my friends & family.
Yesterday saw the movies forrest gump (i am watching it for the 3 rd time
) and alien vs predator with friends.I would not suggest a car LCD monitor for the very reason that the pixelation would be too much atleast for me.That's is why most of the people prefer the so much TOUTED SAMSUNG 10.6" WXGA or a 17" LCD.The pixel size matters most to me.Else you will see so many artifacts on the screen.
I guess SAMSUNG's 10.6" is unavailable in INDIA as of now.You can buy LEXAN from paharganj for around Rs 250.
I guess SAMSUNG's 10.6" is unavailable in INDIA as of now.You can buy LEXAN from paharganj for around Rs 250.
diy projector
hi umesh
As you know i am from faridabad and i want to see your projector should i visit to your home. i want to see PJ in front of me so i can analys better.
my email Id: harishkr.pal@gmail.com
you should give your address & contact no in my mail and tell me when you should available at home so we can meet.
thanx umesh
harish
hi umesh
As you know i am from faridabad and i want to see your projector should i visit to your home. i want to see PJ in front of me so i can analys better.
my email Id: harishkr.pal@gmail.com
you should give your address & contact no in my mail and tell me when you should available at home so we can meet.
thanx umesh
harish
hi
hello,
i am back from exam. got my box made by a carpenter.i won't be able to use my projection lens, thanks to the short FFC of my LCD. got my intial projections with fresnel yesterday. will fix the fresnel today.
can someone tell me what is the exact function of a triplet lens? it seems to be a converging lens. i am getting good images on wall without using triplet. for that matter, i got decent images by placing 2 magnifying lenses in front of each other.
another odd thing, people place fresnels immediately before or after LCD. i get a better image without the triplet when i place the LCD at focal length of fresnel.
hello,
i am back from exam. got my box made by a carpenter.i won't be able to use my projection lens, thanks to the short FFC of my LCD. got my intial projections with fresnel yesterday. will fix the fresnel today.
can someone tell me what is the exact function of a triplet lens? it seems to be a converging lens. i am getting good images on wall without using triplet. for that matter, i got decent images by placing 2 magnifying lenses in front of each other.
another odd thing, people place fresnels immediately before or after LCD. i get a better image without the triplet when i place the LCD at focal length of fresnel.
hi harish
hi,
do you mean to say that if i want to place my PJ farther from wall,then only triplet is needed? i mean i am going to place my PJ at about 10 to 12 feet from the wall.
to tell you, i am experimenting with a 2.5" LCD( i opened a JXD portable media player which has a TV line in port). i tried with fresnel but it eats up too much light. so i am trying with hand held magnifiers. i have 2 of them one of focal length 25cm and the other 20 cm. if i place them close, i get the largest picture, whcih is much clearer but smaller than fresnel. all this is possible because i am using small LCD.
i know many people will be surprised with that size of LCD but i will post images as soon as possible.
hi,
do you mean to say that if i want to place my PJ farther from wall,then only triplet is needed? i mean i am going to place my PJ at about 10 to 12 feet from the wall.
to tell you, i am experimenting with a 2.5" LCD( i opened a JXD portable media player which has a TV line in port). i tried with fresnel but it eats up too much light. so i am trying with hand held magnifiers. i have 2 of them one of focal length 25cm and the other 20 cm. if i place them close, i get the largest picture, whcih is much clearer but smaller than fresnel. all this is possible because i am using small LCD.
i know many people will be surprised with that size of LCD but i will post images as soon as possible.
Composite reply
For DIY's sake you can play around with smaller LCDs but that is not gonna do you any good as the pixel size and consequently the screendor would be too much to watch the image.In a nutshell that would be a TOY not a HOME THEATER PJ.To me the min pixel pitch MUST BE at least .295mm which is the pixel pitch in most of the 15" LCDs.Anything bigger than that would not be worth trying.People have been going after 10.6 SAMSUNG one because the pixel pitch is 0.1mm which should make the image watchable from closer distances.
As for using the fresnel alone, i did try it but that doesnot work as the fresnel can never focus such a large area.You can very well project with just the triplet or anyother convex lens but the brightness would be too low.You can try holding the triplet in front of the LCD working at full brightness and contrast in a completely dark room.
Harish you better get in touch with me on the net or the given addresses as of now.
For DIY's sake you can play around with smaller LCDs but that is not gonna do you any good as the pixel size and consequently the screendor would be too much to watch the image.In a nutshell that would be a TOY not a HOME THEATER PJ.To me the min pixel pitch MUST BE at least .295mm which is the pixel pitch in most of the 15" LCDs.Anything bigger than that would not be worth trying.People have been going after 10.6 SAMSUNG one because the pixel pitch is 0.1mm which should make the image watchable from closer distances.
As for using the fresnel alone, i did try it but that doesnot work as the fresnel can never focus such a large area.You can very well project with just the triplet or anyother convex lens but the brightness would be too low.You can try holding the triplet in front of the LCD working at full brightness and contrast in a completely dark room.
Harish you better get in touch with me on the net or the given addresses as of now.
hi umeshkumar
hi,
what you are saying about screendoor effect is right but only when i am at less than 5 feet from the screen. if i sit farther, somehow it does not disturb me , probably because i am not a videophile( i hope this word exists).i have tried with trailers only, yet to watch a fuul length movie.
anyway, here ar pictures of my attempt
hi,
what you are saying about screendoor effect is right but only when i am at less than 5 feet from the screen. if i sit farther, somehow it does not disturb me , probably because i am not a videophile( i hope this word exists).i have tried with trailers only, yet to watch a fuul length movie.
anyway, here ar pictures of my attempt
Attachments
jaudere
Well my friend you yourself have admitted of the poor image quality.My take on making a PJ is that it should be SPECTACULAR projection wise or else what is the fun of making it if it produces a mediocre quality image.It is already big or so to say it has very bad form factor and if it projects like wise than that would be like a pimple grown upon the ulcer
.A reasonable PJ would cost over 10000-12000 Rs atleast.One could either go for a readymade chinese ones for that matter.BENQ PJs range starts from 30000 Rs.However veterans in this feild donot subscribe to buying evn the low range commercial PJs.
So the best thing would be to get hold of a small LCD with atleast XGA resolution which is smaller than 15".The smaller the better.
Well my friend you yourself have admitted of the poor image quality.My take on making a PJ is that it should be SPECTACULAR projection wise or else what is the fun of making it if it produces a mediocre quality image.It is already big or so to say it has very bad form factor and if it projects like wise than that would be like a pimple grown upon the ulcer
.A reasonable PJ would cost over 10000-12000 Rs atleast.One could either go for a readymade chinese ones for that matter.BENQ PJs range starts from 30000 Rs.However veterans in this feild donot subscribe to buying evn the low range commercial PJs.So the best thing would be to get hold of a small LCD with atleast XGA resolution which is smaller than 15".The smaller the better.
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