DIY Video Projector Part II - Page 111

Iceshack · 13th February 2003, 05:28 AM

That is really not nice at all.What is this world comming to when this happens.It is out and out stealing.I hope you have a way of going after this person/s that did this to you.

PEBurton · 14th February 2003, 07:11 PM

I have read for what seems like days, weeks and months, trying to get caught up to where everyone is at the present time. I would like to make an observation and ask a question at the same time.

It seems in the quest to get better picture quality for the OHP at first, and then in the Custom built projectors to follow, everyone is going to a larger screen. Larger screens provide better res and are cheaper I am assuming.

But with the larger screen you require much more light and with the light comes the heat problems and heat displacement measures i.e. glass, low e glass and the likes, which are not 100% effecient so you need even more light, which washes out the screen, and the resulting image is not bright enough so you go to a bigger lcd.

With the bigger screens you require more optics to make the larger LCD image evenly lit and small enough to fit on the projection lens.

and the cycle starts all over.

I have looked at the lcd projectors and they are not getting bigger as they are getting brighter and better.

Would it not be easier to start with a very high quality small LCD which would be able to handle a smaller more focuses back light sorce having less heat problems and less optics to blow the immage down then blow it back up again to view.

I am no scientist but I am learning, but it makes sence to me. In this case I am not sure bigger is better. We seam to be making bigger and bigger which needs brighter and brighter which creates hotter and hotter, which requires more low eglass and cold lenses which cuts down on the bigger light source you just put in.

Am I totaly off here or does it make sence?

Thank you for taking the time to read and respond.
PEBurton

PEBurton · 14th February 2003, 07:22 PM

http://www.vfmstore.com/tv212.htm I wonder if this is good enough... I dont think so... What do you think.

zardoz · 14th February 2003, 08:10 PM

I believe you are right...this LCD will be "unworthy". You have the right idea but there is a problem....as far as I know NO ONE has managed to find a "small" LCD that was worth buying for the money asked or the performance offered. What I mean to say is...."tiny perfect LCD's" are worth their weight in gold to the seller and "affordable small LCD's" are crappy low res toys.

Keep hunting and maybe you will save the day for us all.

zardoz

Quote:

Originally posted by PEBurton
http://www.vfmstore.com/tv212.htm I wonder if this is good enough... I dont think so... What do you think.

Redevil · 15th February 2003, 02:20 AM

Hey Guys
There is a sight on the net that have a good LED
assortment
126 clear white L.E.D s for about $270.00
Go check it it out.
L8r
Joe
http://members.shaw.ca/sagelighting/...bs_specifi.htm

slize · 15th February 2003, 01:09 PM

sorry to say that, but leds won't work. do you see the brightness of these things: white leds 5000-7500 mcd.

5000-7500 milli candela!!! ; candela = lumens

we are talking about 5 to 7,5 lumens !!!!!!!

in this forum we have problems with lamps which have 10000 to 35000 lumens because they are not bright enough to make a good picture.

And u are really think about 5 to 7,5 lumens. I would say forget about the led thing... there might be refelctors which make the leds 5 times brighter but even then, we are just talking about 35 lumens...

so may be they are good for a backlight of a tft but they will be never good enough for a projection, or if so they won't be payable...

XanderSnyder · 15th February 2003, 08:48 PM

I would tend to disagree with you about the led's. I am a member of diyprojection.com and we have been bouncing arround the idea of leds for a while (by the way if you havent seen that forum you need to it rocks and every is really helpful) but i was thinking about using an array of 120 to 140 10000mcd super bright white leds (these average about 12.3 to 20 lumens depending on quality) thanks that that fourm we have found a place that sells then in packs of 20 for $20.14 US, ill post the link later. so that meens that the output would range between 1,722 lumens and 2,800 lumens, if you were to use that in conjunction with BRF film from 3m that should be birght enough to watch in a dimly lit room

Xander

Redevil · 15th February 2003, 10:10 PM

The future is L.E.D lighting.
I have already seen trucks in my area using the LEDS for there
brake lights. They are also thinking of using them in our street lights. Ten year life span, no color shifting, very very low power
consumption. They will also be making car headlight with these things.
Then I grabed my $30.00 LED flashlight and put it behind my LCD
and behold, I laughed. Not much of a picture for a two LED
light, but sure enought it was there.
It may be worth it for someone to atleast try it.
L8r

noodles · 17th February 2003, 12:05 AM

A Luxeon Star LED has about 660 candela. And if candela = lumens... then well, you know the rest.

verbose mustafa · 17th February 2003, 01:34 AM

daaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! cd does not = lumens!!! I am going to make a section of my web site on how to convert the numbers. One 10,000 mcd led with a viewing angle of 15 degres is 2.1509 lumens. I lexeon emitter (if i remember from their website) can go as high as high as 150 lumens.

13th February 2003, 05:28 AM	#1101
Iceshack diyAudio Member Join Date: Feb 2003 Location: Near Ottawa	Riped off That is really not nice at all.What is this world comming to when this happens.It is out and out stealing.I hope you have a way of going after this person/s that did this to you.

14th February 2003, 07:11 PM	#1102
PEBurton diyAudio Member Join Date: Feb 2003 Location: Washinton	Hello All I have read for what seems like days, weeks and months, trying to get caught up to where everyone is at the present time. I would like to make an observation and ask a question at the same time. It seems in the quest to get better picture quality for the OHP at first, and then in the Custom built projectors to follow, everyone is going to a larger screen. Larger screens provide better res and are cheaper I am assuming. But with the larger screen you require much more light and with the light comes the heat problems and heat displacement measures i.e. glass, low e glass and the likes, which are not 100% effecient so you need even more light, which washes out the screen, and the resulting image is not bright enough so you go to a bigger lcd. With the bigger screens you require more optics to make the larger LCD image evenly lit and small enough to fit on the projection lens. and the cycle starts all over. I have looked at the lcd projectors and they are not getting bigger as they are getting brighter and better. Would it not be easier to start with a very high quality small LCD which would be able to handle a smaller more focuses back light sorce having less heat problems and less optics to blow the immage down then blow it back up again to view. I am no scientist but I am learning, but it makes sence to me. In this case I am not sure bigger is better. We seam to be making bigger and bigger which needs brighter and brighter which creates hotter and hotter, which requires more low eglass and cold lenses which cuts down on the bigger light source you just put in. Am I totaly off here or does it make sence? Thank you for taking the time to read and respond. PEBurton

14th February 2003, 07:22 PM	#1103
PEBurton diyAudio Member Join Date: Feb 2003 Location: Washinton	Example of 2 inch LCD http://www.vfmstore.com/tv212.htm I wonder if this is good enough... I dont think so... What do you think.

15th February 2003, 01:09 PM	#1106
slize diyAudio Member Join Date: May 2002	leds won't work sorry to say that, but leds won't work. do you see the brightness of these things: white leds 5000-7500 mcd. 5000-7500 milli candela!!! ; candela = lumens we are talking about 5 to 7,5 lumens !!!!!!! in this forum we have problems with lamps which have 10000 to 35000 lumens because they are not bright enough to make a good picture. And u are really think about 5 to 7,5 lumens. I would say forget about the led thing... there might be refelctors which make the leds 5 times brighter but even then, we are just talking about 35 lumens... so may be they are good for a backlight of a tft but they will be never good enough for a projection, or if so they won't be payable...

15th February 2003, 08:48 PM	#1107
XanderSnyder diyAudio Member Join Date: Feb 2003 Location: D/FW Texas	Don't rule out led's I would tend to disagree with you about the led's. I am a member of diyprojection.com and we have been bouncing arround the idea of leds for a while (by the way if you havent seen that forum you need to it rocks and every is really helpful) but i was thinking about using an array of 120 to 140 10000mcd super bright white leds (these average about 12.3 to 20 lumens depending on quality) thanks that that fourm we have found a place that sells then in packs of 20 for $20.14 US, ill post the link later. so that meens that the output would range between 1,722 lumens and 2,800 lumens, if you were to use that in conjunction with BRF film from 3m that should be birght enough to watch in a dimly lit room Xander


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15th February 2003, 02:20 AM	#1105
Redevil diyAudio Member Join Date: May 2002	Hey Guys There is a sight on the net that have a good LED assortment 126 clear white L.E.D s for about $270.00 Go check it it out. L8r Joe http://members.shaw.ca/sagelighting/...bs_specifi.htm

15th February 2003, 10:10 PM	#1108
Redevil diyAudio Member Join Date: May 2002	The future is L.E.D lighting. I have already seen trucks in my area using the LEDS for there brake lights. They are also thinking of using them in our street lights. Ten year life span, no color shifting, very very low power consumption. They will also be making car headlight with these things. Then I grabed my $30.00 LED flashlight and put it behind my LCD and behold, I laughed. Not much of a picture for a two LED light, but sure enought it was there. It may be worth it for someone to atleast try it. L8r

17th February 2003, 12:05 AM	#1109
noodles diyAudio Member Join Date: Jun 2002 Location: Gulf Coast, Punk	A Luxeon Star LED has about 660 candela. And if candela = lumens... then well, you know the rest.

17th February 2003, 01:34 AM	#1110
verbose mustafa diyAudio Member Join Date: Nov 2002 Location: Massachusetts	daaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! cd does not = lumens!!! I am going to make a section of my web site on how to convert the numbers. One 10,000 mcd led with a viewing angle of 15 degres is 2.1509 lumens. I lexeon emitter (if i remember from their website) can go as high as high as 150 lumens.

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