Screendoor Effect!
I finally built the projector out of THERMOCOLE! 😀 nope, the lamp did not melt it as I had put 2 fans across the light beam. BUT, here are the problems I am facing.
1. THe image is not as bright as the actual light from the Lamp. If i just throw light from the lamp on the wall, it is pretty bright, but through the Fresnels and the LCD, the resultant projected image is pretty dull. I am using a 150 W Osram Metal Halide. Has anybody faced this problem. What could be the problems? I am using page magnifiers bought from here
Stationaryworld@ebay
These are not glass fresnels (I dont know if glass ones exist) but flexible sheet type fresnels. I am using triplet from lensel which I mentioned about in my previous post.
If the fresnels are meant to collimate light and throw it on the LCD, then I think the light ought to be more concentrated towards the projection. But it is not happening I think.
2. THe text on webpages is not readable, it is faded, especially if the page is white in colour. Plus even the colours are not as vivid as on my CRT.
Any tips on how to fine tune the projection. My projection distance is 6 feet and image is around 6 feet wide by 4 feet high.
I am also getting screen door effect but after I read this page, I realised that it really is more of a "psychological" issue.
nitpicker's delight
yeah, just sit back. DONT GO NEAR THE SCREEN! ITS A HOME THEATER. NOT A MICROSCOPE! LOL!
I finally built the projector out of THERMOCOLE! 😀 nope, the lamp did not melt it as I had put 2 fans across the light beam. BUT, here are the problems I am facing.
1. THe image is not as bright as the actual light from the Lamp. If i just throw light from the lamp on the wall, it is pretty bright, but through the Fresnels and the LCD, the resultant projected image is pretty dull. I am using a 150 W Osram Metal Halide. Has anybody faced this problem. What could be the problems? I am using page magnifiers bought from here
Stationaryworld@ebay
These are not glass fresnels (I dont know if glass ones exist) but flexible sheet type fresnels. I am using triplet from lensel which I mentioned about in my previous post.
If the fresnels are meant to collimate light and throw it on the LCD, then I think the light ought to be more concentrated towards the projection. But it is not happening I think.
2. THe text on webpages is not readable, it is faded, especially if the page is white in colour. Plus even the colours are not as vivid as on my CRT.
Any tips on how to fine tune the projection. My projection distance is 6 feet and image is around 6 feet wide by 4 feet high.
I am also getting screen door effect but after I read this page, I realised that it really is more of a "psychological" issue.
nitpicker's delight
yeah, just sit back. DONT GO NEAR THE SCREEN! ITS A HOME THEATER. NOT A MICROSCOPE! LOL!
HELP! MY LCD is DEAD!!!
I removed the antiglare (shiny mirror like coating). It was like a sticker but i had to use considerable force to pull it off. I even pressed the LCD with my bare fingers while pulling the sticker type coating off. There was another coating beneath the anti glare coating but i did not pull it off as i didn't know what it was. I think it must have been the polariser film. Yes, i left the polariser film intact.
I also accidentally unplugged the FFC but was able to plug it back in after cleaning. This was not the white coloured FFC but the brown transluscent strip that finally links the LCd to the circuitry.
To remove the adhesive used to stick the antiglare coating, i used easy-off BANG (dont ask me what i was thinking, but it just happened) and water. THen I thought that I will get a bright crisp image with great colours. But when i put the LCd in front of the lam p and turned it on, there was nothing! it just turned from translucent to dark blue/black and there was a 1" wide strip that was not working on the LCD. I think you would call them DEAD PIXELS in technical jargon. What was my mistake? Is there no hope for the LCD now? Can i do anything to get back the picture? please tell me because it was worth 4000 Rs and i really dont want to waste another 4000 rs making the same mistake on another LCD!
I removed the antiglare (shiny mirror like coating). It was like a sticker but i had to use considerable force to pull it off. I even pressed the LCD with my bare fingers while pulling the sticker type coating off. There was another coating beneath the anti glare coating but i did not pull it off as i didn't know what it was. I think it must have been the polariser film. Yes, i left the polariser film intact.
I also accidentally unplugged the FFC but was able to plug it back in after cleaning. This was not the white coloured FFC but the brown transluscent strip that finally links the LCd to the circuitry.
To remove the adhesive used to stick the antiglare coating, i used easy-off BANG (dont ask me what i was thinking, but it just happened) and water. THen I thought that I will get a bright crisp image with great colours. But when i put the LCd in front of the lam p and turned it on, there was nothing! it just turned from translucent to dark blue/black and there was a 1" wide strip that was not working on the LCD. I think you would call them DEAD PIXELS in technical jargon. What was my mistake? Is there no hope for the LCD now? Can i do anything to get back the picture? please tell me because it was worth 4000 Rs and i really dont want to waste another 4000 rs making the same mistake on another LCD!
auldthief,
I am very sorry to hear that ur lcd is dead.
There is no way to repair it.
But, u have mentioned u pulled out "shiny mirror like coating"
Actually, the antiglare is a matt finish layer, not shiny..
Ok, now the mistake u have done.. is that u handled the lcd roughly. It is a very delicate thing, and i think u have bend the ffc cable near the joint. It happened to me once, and lcd went completely blank.
Next time, (with another LCD) what i did is, after stripping the lcd, i applied araldite (adhesive) to the ffc joint areas, which i felt is fragile or delicate.
Finally, dont try to remove your antiglare for improving brightness, it will not gain you a noticable improvement. Try to change the contrast/brightness settings in the lcd controls and try a 250Watts bulb..
Hope it helps..
I am very sorry to hear that ur lcd is dead.
There is no way to repair it.
But, u have mentioned u pulled out "shiny mirror like coating"
Actually, the antiglare is a matt finish layer, not shiny..
Ok, now the mistake u have done.. is that u handled the lcd roughly. It is a very delicate thing, and i think u have bend the ffc cable near the joint. It happened to me once, and lcd went completely blank.
Next time, (with another LCD) what i did is, after stripping the lcd, i applied araldite (adhesive) to the ffc joint areas, which i felt is fragile or delicate.
Finally, dont try to remove your antiglare for improving brightness, it will not gain you a noticable improvement. Try to change the contrast/brightness settings in the lcd controls and try a 250Watts bulb..
Hope it helps..
Well my response to nit pickers is that i am not doing that.Waht i said is vividly echoed in the fact that advance builders are upgrading to smaller(for overall PJ SIZE) and higher resolution LCDS( for larger images viewable from a nearer distance).
Just visit www.beyondinfinite.com for LCDs but mind it those are steeply high priced else i have completed my dream machine.
Just visit www.beyondinfinite.com for LCDs but mind it those are steeply high priced else i have completed my dream machine.
i can arrange fresnel for 15'' wide & 17"wide screen lcds
hi
i am kumar
i can arrange pro fresnel lens for 15,17,19 lcd,
220mm.320mm,550mm r available with me,
it can cover full of 15 wide,17,19 inches lcd,
pls contact
projectordiy@yahoo.in
🙂
hi
i am kumar
i can arrange pro fresnel lens for 15,17,19 lcd,
220mm.320mm,550mm r available with me,
it can cover full of 15 wide,17,19 inches lcd,
pls contact
projectordiy@yahoo.in
🙂
Thanks VNS. Reassuring word that prod me to go on! 🙂 However now I am thinking that I'd rather go with a 400 W lamp. Might as well take the extra risk for excellent results than the same risk for mediocre ones. I am also stuck at the fabrication part. I really dont want to get anything concrete made till I am sure of the results, and I cannot be sure of the results till I get something concrete made. How did you solve this dilemma? 😀
vnsnair said:
Dear Auldthief,
I also finished my projector , which is giving good results.
7" LCD ( World Tech DVD player)
150 Watts MH ( Osram- Powerball- Made in Germany)
190 mm fresnel (Sheet magnifier)
90 mm ordinary magnifier (instead of triplet)
Computer cooling fans ( 2 to blow and 1 as exhaust)
6x4 feet screen (Sunpack white sheet)
80 " Diagonal
Throw distance 13 feet
Ofcourse , there is slight defocussed picture at the edges
which are very negligible. Overall picture is bright enough. In the day time also, we can enjoy the picture even if it is dull.
In my opinion, for 7 " LCD, 150 watts lamp is sufficient.
The beam of the lamp is very wide.
we have to focus the beam . There lies the trick. The beam should be equal to the LCD screen size. Donot concentrate at a single sharp point as we do with lenses.
To achive this, I removed the original reflector from the lamp, and used an auto head lamp reflector (Mazda Head light). I had to cut and resize the reflector to insert the MH bulb. With some trial and error such a position can be found, and fix it .
The result was amazing. I got the brightest picture out of it. Also there is no need of rear fresnel.
I can say that, my picture quality is 95% ok.
"150 watts People, pse give a try"
I also finished my projector , which is giving good results.
7" LCD ( World Tech DVD player)
150 Watts MH ( Osram- Powerball- Made in Germany)
190 mm fresnel (Sheet magnifier)
90 mm ordinary magnifier (instead of triplet)
Computer cooling fans ( 2 to blow and 1 as exhaust)
6x4 feet screen (Sunpack white sheet)
80 " Diagonal
Throw distance 13 feet
Ofcourse , there is slight defocussed picture at the edges
which are very negligible. Overall picture is bright enough. In the day time also, we can enjoy the picture even if it is dull.
In my opinion, for 7 " LCD, 150 watts lamp is sufficient.
The beam of the lamp is very wide.
we have to focus the beam . There lies the trick. The beam should be equal to the LCD screen size. Donot concentrate at a single sharp point as we do with lenses.
To achive this, I removed the original reflector from the lamp, and used an auto head lamp reflector (Mazda Head light). I had to cut and resize the reflector to insert the MH bulb. With some trial and error such a position can be found, and fix it .
The result was amazing. I got the brightest picture out of it. Also there is no need of rear fresnel.
I can say that, my picture quality is 95% ok.
"150 watts People, pse give a try"
THanks dude! U gave me a reason to go ahead. I was also working with the same config but my results were not bright enough to satisfy me. Moreover I damaged my 10" monitor and was thinking of going for 15" now for improved pictures. Also I was thinking that with 400 W i will get better results. But as per you, even 150 W, which I am using right now, is sufficient. So i will remove the lamp from the floodlight enclosure and try your reflector method. I am also using sheet magnifiers but they get distorted due to heat and hence the light is not evenly spread out and sides of images are blurred out. What have u done to protect your fresnels from melting/getting deformed?
What kind of enclosure have u used?
what have u used to hold the magnifiers in place and keep the LCD, fresnels and lens aligned?
are you able to read text, e.g webpages on your projection? What about whites? can you see the mouse pointer on a white background? I an not getting sharp and bright images. Cant see the mouse pointer or read text like on this page. So what tips do you have for me? 🙂
What kind of enclosure have u used?
what have u used to hold the magnifiers in place and keep the LCD, fresnels and lens aligned?
are you able to read text, e.g webpages on your projection? What about whites? can you see the mouse pointer on a white background? I an not getting sharp and bright images. Cant see the mouse pointer or read text like on this page. So what tips do you have for me? 🙂
vu2pda said:
diy pj
hello diyers,
finally i completed my projector i am giving you link
http://in.youtube.com/watch?v=YySWxRLWJNM
hello diyers,
finally i completed my projector i am giving you link
http://in.youtube.com/watch?v=YySWxRLWJNM
diy projector
hello diyers,
i am watching picture 60" on wall but i worried about colour not proper colour are come on wall every thing are just yellowise face, legs, hands of person are come. i need proper colour what to do now ? any body in this forum have solution ?
hello diyers,
i am watching picture 60" on wall but i worried about colour not proper colour are come on wall every thing are just yellowise face, legs, hands of person are come. i need proper colour what to do now ? any body in this forum have solution ?
Dear Auldthief,
Tnx for ur response. Yday. I made little more change. Removed the front fresnel and placed it at back of the LCD (collimator). Now the brightness has improved. (Practical has importance than theory, atleast in my case).
All my family members were enjoying Sunday movies on the BIG SCREEN of 80 - 90inches. I hv limited space. otherwise I cud hv increase the screen size further.
Auldthief,
my projector is cool with the three fans.No fresnel heating pbm. Fresnel is directly attached with LCD screen using adhesive tape.
There is an ordinary thick glass inbetween light and LCD.
Enclosure is made up of 6mm plywood. But little lengthy.(40")
40x10x9 inches. The distance between light and LCD is 17". This was purposely done to minimise heating pbms.
My video input is from a satellite RX. Not yet tried computer output. So dont knw abt small texts. But for viewing TV, it is more than sufficient. Colours are vy bright and clear.
Auldthief, what kind of lense r u using? Is it a triplet or an ordinary magnifying lense? If it is an ordinary lense, covering the edges of the lense a little will reduce blurring pbm.(trial and error)
If it is triplet, 150 watts may not give u good results.
Sorry for the lengthy reply
Tnx for ur response. Yday. I made little more change. Removed the front fresnel and placed it at back of the LCD (collimator). Now the brightness has improved. (Practical has importance than theory, atleast in my case).
All my family members were enjoying Sunday movies on the BIG SCREEN of 80 - 90inches. I hv limited space. otherwise I cud hv increase the screen size further.
Auldthief,
my projector is cool with the three fans.No fresnel heating pbm. Fresnel is directly attached with LCD screen using adhesive tape.
There is an ordinary thick glass inbetween light and LCD.
Enclosure is made up of 6mm plywood. But little lengthy.(40")
40x10x9 inches. The distance between light and LCD is 17". This was purposely done to minimise heating pbms.
My video input is from a satellite RX. Not yet tried computer output. So dont knw abt small texts. But for viewing TV, it is more than sufficient. Colours are vy bright and clear.
Auldthief, what kind of lense r u using? Is it a triplet or an ordinary magnifying lense? If it is an ordinary lense, covering the edges of the lense a little will reduce blurring pbm.(trial and error)
If it is triplet, 150 watts may not give u good results.
Sorry for the lengthy reply
diy projector
hello vnsnair,
i am using Sony home threatre it cost me around 17500/- but there is no colour adjustment in dvd player. Is it possible that brightness is a matter for colour ? because i am using 150W MH lamp.
i think colour is adjusted in only LCD monitor i try to do but there is no improvement i am using 7" LCD monitor (World Tech). When i see in lcd monitor colour are appropriate but in wall fade colour are come and face become yellow i don't know what is reason behind it any body facing this kind of problem ?
please help me?
hello vnsnair,
i am using Sony home threatre it cost me around 17500/- but there is no colour adjustment in dvd player. Is it possible that brightness is a matter for colour ? because i am using 150W MH lamp.
i think colour is adjusted in only LCD monitor i try to do but there is no improvement i am using 7" LCD monitor (World Tech). When i see in lcd monitor colour are appropriate but in wall fade colour are come and face become yellow i don't know what is reason behind it any body facing this kind of problem ?
please help me?
Harish_pal,
Normally it happens because of the colour temperature of the metal halide bulb. It will be little bit yellowish if the colour temp is below 5500 K , and bit blueish if it's above 5500K. I am using a 6500K bulb, which is a bit blueish. If your lcd is having a setting for colour temp, u can use that (like, warm, cool etc..)
Otherwise, only option coming to my mind is to use computer input and use vlc player. Atleast you try using input from PC and try changing the colour settings, so that u can come to a conclusion..
regards,
VNS..
Normally it happens because of the colour temperature of the metal halide bulb. It will be little bit yellowish if the colour temp is below 5500 K , and bit blueish if it's above 5500K. I am using a 6500K bulb, which is a bit blueish. If your lcd is having a setting for colour temp, u can use that (like, warm, cool etc..)
Otherwise, only option coming to my mind is to use computer input and use vlc player. Atleast you try using input from PC and try changing the colour settings, so that u can come to a conclusion..
regards,
VNS..
diy pj
nair thanks for your kind suggestion i think you are right my lamp some time have bluish and some yellowish. I did not have vga input so i can't connect to pc i thinks better option is that update MH Lamp into powerstar or powerball 250W or 400W i thinks lumen is 20000K which better
harish
nair thanks for your kind suggestion i think you are right my lamp some time have bluish and some yellowish. I did not have vga input so i can't connect to pc i thinks better option is that update MH Lamp into powerstar or powerball 250W or 400W i thinks lumen is 20000K which better
harish
Look for 250 watts bulb with the lowest arc size (size of the light emitting portion of the bulb )
I am using a powerstar 250 watts single end.
Tyr to get a double end bulb ,as it's arc size is smaller
20000 is the life of the bulb in hours..
try to get a 5500K color temp bulb.
I am using a powerstar 250 watts single end.
Tyr to get a double end bulb ,as it's arc size is smaller
20000 is the life of the bulb in hours..
try to get a 5500K color temp bulb.
Hi Guys, 🙂
I have been brushing up on my theory the past couple of months. I have read the entire forum till date and am going to start my build really soon. Guys please have a look at the specifications posted bellow and let me know if know if there are any changes needed
In Order Starting From Lamp
Lamp - Osram 250 w
Tempered Glass
Fresnel 1 - 220 mm
L.C.D. - Super 7" Inch
Fresnel 2 - 330 mm
Lens - Triplet 315 mm
Thanks in advance
I have been brushing up on my theory the past couple of months. I have read the entire forum till date and am going to start my build really soon. Guys please have a look at the specifications posted bellow and let me know if know if there are any changes needed
In Order Starting From Lamp
Lamp - Osram 250 w
Tempered Glass
Fresnel 1 - 220 mm
L.C.D. - Super 7" Inch
Fresnel 2 - 330 mm
Lens - Triplet 315 mm
Thanks in advance
Hello Phoenix,
You are having the best combination to start with.
Go ahead... and do post us the progress..
btw, what is the native resolution of the 7" lcd?
You are having the best combination to start with.
Go ahead... and do post us the progress..
btw, what is the native resolution of the 7" lcd?
LCD Projector to purchase
I am from chennai india.
If any one like to make a LCD For me . Please let me know..
I will purchase an LCD Projector from them
I am from chennai india.
If any one like to make a LCD For me . Please let me know..
I will purchase an LCD Projector from them
Hello Guys
Thanks for the encouragement vnsnair. I haven't purchased the Fresnels as yet i am planing to do so from the Lensel Store in pune. I called them a couple of days ago and they have sent me list of available Fresnels which has totally confused me. After reading the theory on a couple of forums i was planing on having a split setup with one Fresnel behind the LCD and one Fresnel in front (Please let me know if this setup will work?) Guys i am posting a link of the Word File containing all the Fresnels available at Lensel could any one please guide me with which split fresnel would best suit my 7" inch LCD with resolution of 640x480
http://www.yousendit.com/download/TTZsOU1XRSs4aU9Ga1E9PQ
Thanks for the encouragement vnsnair. I haven't purchased the Fresnels as yet i am planing to do so from the Lensel Store in pune. I called them a couple of days ago and they have sent me list of available Fresnels which has totally confused me. After reading the theory on a couple of forums i was planing on having a split setup with one Fresnel behind the LCD and one Fresnel in front (Please let me know if this setup will work?) Guys i am posting a link of the Word File containing all the Fresnels available at Lensel could any one please guide me with which split fresnel would best suit my 7" inch LCD with resolution of 640x480
http://www.yousendit.com/download/TTZsOU1XRSs4aU9Ga1E9PQ
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