and here is the first image....camera deff doesn't do it justice. Image is fairly brighter in person, plus the projector does not have a lid or walls so it was bleeding alot of light that washed out the image a bit. The image was 7'6'' wide and about 4'8 tall.....i was happy 🙂
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when I said top left I ment the top left of the whole screen....
i am gettin a lot of heat build up on the LCD. If I put a peice of UV and IR glass after the light will this help matters??? Please help.
Thats all for now....till next sunday 🙁
i am gettin a lot of heat build up on the LCD. If I put a peice of UV and IR glass after the light will this help matters??? Please help.
Thats all for now....till next sunday 🙁
wassup notta
im new at this and wanna build one myself
about how much did it cost to buy all the equipment to build it?
and where did you learn how to build it?
thanks
im new at this and wanna build one myself
about how much did it cost to buy all the equipment to build it?
and where did you learn how to build it?
thanks
hot LCD
It definitely would help to add something to control the IR in the light reaching the LCD, and you must have UV filtering or you will damage your fresnel & LCD. Different things have been used to control IR: hot mirror, heat absorbing glass, tempered glass, etc. I use 0 degree hot mirror just after the lamp & my fresnels & LCD never even get warm. I also use a thin piece of Lexan XL10 to support my fresnels AND filter out the UV.
It would also be a good idea to have some active cooling of the spaces above and below the LCD. When you put it all in a box, you could make the airflow going into the lightbox traverse the top of the LCD, and then the bottom of the LCD before it gets to the blower fan. Until then, you might want to add a fan just to blow some air into those spaces.
Sure is satisfying when you get that first screen image! I just passed another milestone tonight: My wife and I saw a DVD of a movie on our neighbor's plasma screen, and then she said: "I want to see that again, but this time on your projector." So my biggest critic (and my best supporter) thinks my PJ is good enough to watch...
It definitely would help to add something to control the IR in the light reaching the LCD, and you must have UV filtering or you will damage your fresnel & LCD. Different things have been used to control IR: hot mirror, heat absorbing glass, tempered glass, etc. I use 0 degree hot mirror just after the lamp & my fresnels & LCD never even get warm. I also use a thin piece of Lexan XL10 to support my fresnels AND filter out the UV.
It would also be a good idea to have some active cooling of the spaces above and below the LCD. When you put it all in a box, you could make the airflow going into the lightbox traverse the top of the LCD, and then the bottom of the LCD before it gets to the blower fan. Until then, you might want to add a fan just to blow some air into those spaces.
Sure is satisfying when you get that first screen image! I just passed another milestone tonight: My wife and I saw a DVD of a movie on our neighbor's plasma screen, and then she said: "I want to see that again, but this time on your projector." So my biggest critic (and my best supporter) thinks my PJ is good enough to watch...
hey guy...thanks for the input buddy...
what do you mean by traverse??? I am kinda lost...and really do not know where I could put a fan to cool the lcd and fresnells...if you could maybe....if its not to much of a hassel ms paint me up a picture of what you ment by traverse airflow that would be awesome.
I am deff gonna get a piece of UV and IR glass to put inbeween the light and the LCDs. I cannot use a hot mirror anymore cause I do not want to change my design. But if I get a fan on the fresnels and lcd and have UV and IR filter...that should be decent enough...plus my bulb has some UV controll built in...
lcd cost about 190 on ebay
light and all lenses cost about 75-80
other materials for box cost about 50
(all in USD)
you in no way need to spend this much...some people on here use PSOne and PS2 travel LCD screens and get a decent image...this only cost around 30-50 dollars...
and where did I learn how to do all this....I must give all credit to all the hard working people on this forum....i stumbled onto this site...and read about a million posts...and then worked up enought courage to try myself....
any other questions feel free to ask....
---Drew
what do you mean by traverse??? I am kinda lost...and really do not know where I could put a fan to cool the lcd and fresnells...if you could maybe....if its not to much of a hassel ms paint me up a picture of what you ment by traverse airflow that would be awesome.
I am deff gonna get a piece of UV and IR glass to put inbeween the light and the LCDs. I cannot use a hot mirror anymore cause I do not want to change my design. But if I get a fan on the fresnels and lcd and have UV and IR filter...that should be decent enough...plus my bulb has some UV controll built in...
well laub...
lcd cost about 190 on ebay
light and all lenses cost about 75-80
other materials for box cost about 50
(all in USD)
you in no way need to spend this much...some people on here use PSOne and PS2 travel LCD screens and get a decent image...this only cost around 30-50 dollars...
and where did I learn how to do all this....I must give all credit to all the hard working people on this forum....i stumbled onto this site...and read about a million posts...and then worked up enought courage to try myself....
any other questions feel free to ask....
---Drew
Guy,
Check out the IR and UV glass at diylabs.org and tell me what you think...think that would be ok to put both pieces after my light or do you think that will cut out to much of the light...I would appriciate some suggestions...thanks man
drew
Check out the IR and UV glass at diylabs.org and tell me what you think...think that would be ok to put both pieces after my light or do you think that will cut out to much of the light...I would appriciate some suggestions...thanks man
drew
plastic IR film on glass
I have no experience with this product, but it sounds like something I wanted to try: VK-70 spectrally selective heat film applied to glass. I have been reading about VK-70 for a while with some interest. It is a hot mirror dichroic thin film, but sandwiched between layers of plastic instead of being deposited on a glass surface. It is available from some high-end window tinting companies. It is used on both cars and building windows to let in most of the visible light, while blocking most of the heat.
I think the difference would be that the plastic film on glass would have to go much further away from the lamp. I have hot mirror (on glass) within a few millimeters of my lamp. This stuff would have to go just before the fresnels. From reading the VK-70 specs, it is not really quite as good as standard hot mirror in terms of visible light transmission and IR reflection. But maybe it is good enough! It would certainly make a lot of designs much easier and cheaper if it is.
It IS pretty cheap! You should try it and let us know how it works out. Has anybody else reading this tried it?
By "traverse the LCD", I just meant you could make the airflow blow across the surface of the LCD on one side and then the other side, using air ducts built into the box. The air your pusher fan sends into the light engine has to come from somewhere. It might as well get pulled past all of your other layers first. That is just a matter of building some air paths into your box. Practically free!
I have no experience with this product, but it sounds like something I wanted to try: VK-70 spectrally selective heat film applied to glass. I have been reading about VK-70 for a while with some interest. It is a hot mirror dichroic thin film, but sandwiched between layers of plastic instead of being deposited on a glass surface. It is available from some high-end window tinting companies. It is used on both cars and building windows to let in most of the visible light, while blocking most of the heat.
I think the difference would be that the plastic film on glass would have to go much further away from the lamp. I have hot mirror (on glass) within a few millimeters of my lamp. This stuff would have to go just before the fresnels. From reading the VK-70 specs, it is not really quite as good as standard hot mirror in terms of visible light transmission and IR reflection. But maybe it is good enough! It would certainly make a lot of designs much easier and cheaper if it is.
It IS pretty cheap! You should try it and let us know how it works out. Has anybody else reading this tried it?
By "traverse the LCD", I just meant you could make the airflow blow across the surface of the LCD on one side and then the other side, using air ducts built into the box. The air your pusher fan sends into the light engine has to come from somewhere. It might as well get pulled past all of your other layers first. That is just a matter of building some air paths into your box. Practically free!
NottaClu...for someone with that nick you have done a wonderful job, soon as that LCD is cooled a little and some minoir tweaking im sure you will be a very happy and proud owner of a kick a s s PJ and no doubt have a few envious friends *wink* ......well done 🙂
Ah Guy... bet that made you feel nearly as good as when you first saw an image produced on your first DIY PJ didn't mate 🙂 Would surely have been one proud moment in the Grotke household that evening 🙂
Ah Guy... bet that made you feel nearly as good as when you first saw an image produced on your first DIY PJ didn't mate 🙂 Would surely have been one proud moment in the Grotke household that evening 🙂
does the light from a hot mirror go stright through it, or does it bank the light like a regular mirror. If it just refelcts the heat....and lets the light through....where is a good place to buy one of these???
hot mirror
Hot mirror reflects infrared light (just like a mirror) but transmits visible light (just like glass). Most of the optical supply places sell them, like Rolyn and Edmunds, but they are pretty expensive.
I know of two sellers of surplus hot mirror at reasonable prices:
surplusshed.com has 50 mm by 55 mm squares that don't seem to work very well, with my simple "halogen lamp & burnt finger test".
diybuildergroup.com has 50 mm by 50 mm squares that do seem to work very well in the simple test, and in my projector. I built an aluminum frame to hold four of them, to give me a 100 mm by 100 mm heat filter. I put it right up against my lamp.
diyprojectorcompany.com has a similar item for sale that is a heat reflective plastic window film mounted on glass. This would have to go further from the lamp than real glass hot mirror. Like maybe as a fresnel support 220 mm from the lamp.
Hot mirror reflects infrared light (just like a mirror) but transmits visible light (just like glass). Most of the optical supply places sell them, like Rolyn and Edmunds, but they are pretty expensive.
I know of two sellers of surplus hot mirror at reasonable prices:
surplusshed.com has 50 mm by 55 mm squares that don't seem to work very well, with my simple "halogen lamp & burnt finger test".
diybuildergroup.com has 50 mm by 50 mm squares that do seem to work very well in the simple test, and in my projector. I built an aluminum frame to hold four of them, to give me a 100 mm by 100 mm heat filter. I put it right up against my lamp.
diyprojectorcompany.com has a similar item for sale that is a heat reflective plastic window film mounted on glass. This would have to go further from the lamp than real glass hot mirror. Like maybe as a fresnel support 220 mm from the lamp.
here is another question....
My condesor lens is about 1 inch from the edge of the bulb...it is the 60mm 110fl condensor from diylabs. My first fresnel is 220mm away from the arc of the bulb. Is one inch away from the bulb too far away....or should I move it closer to get a brighter image...tell me what you guys think....
thanks
drew
My condesor lens is about 1 inch from the edge of the bulb...it is the 60mm 110fl condensor from diylabs. My first fresnel is 220mm away from the arc of the bulb. Is one inch away from the bulb too far away....or should I move it closer to get a brighter image...tell me what you guys think....
thanks
drew
NottaClu
I run mine inbetween 3-5mm from the lamp...maybe give that ago matey just make sure the condenser lens has adequate cooling and mounted to allow for a little expansion if it decides it wants to move a 'lil bit buddy ;-) If you don't you may get the same result as a fellow DIY has gotten (one more than one occasion i believe during testing the limits of individual lenses)
I run mine inbetween 3-5mm from the lamp...maybe give that ago matey just make sure the condenser lens has adequate cooling and mounted to allow for a little expansion if it decides it wants to move a 'lil bit buddy ;-) If you don't you may get the same result as a fellow DIY has gotten (one more than one occasion i believe during testing the limits of individual lenses)
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NottaClu said:here is another question....
My condesor lens is about 1 inch from the edge of the bulb...it is the 60mm 110fl condensor from diylabs. My first fresnel is 220mm away from the arc of the bulb. Is one inch away from the bulb too far away....or should I move it closer to get a brighter image...tell me what you guys think....
thanks
drew
Hey Drew
Heres a theoretical sketch of where your condensor and arc should be. You should move your arc in a bit since you are using a condensor. Just use this as a guide as its not really accurate to .01mm (probably more like +/- 2mm, but it should make things a bit brighter.
Mark
Fresnel setup
first fresnel should be at its focal from the bulb correct...no matter if you are using a condensor or not??? I could be wrong but thats how I thought it was. If this is the case...should I just move the condensor back further......I guess I just want to know an easy way to get maximum light over the lcd....for brightness purposes...
thanks
drew
thanks
drew
Re: hot mirror
Do you have a pic of that by any chance? I was just wonderiong how you support the four pieces.
Thanks.
Guy Grotke said:
Do you have a pic of that by any chance? I was just wonderiong how you support the four pieces.
Thanks.
NottaClu said:
By adding a condensor lens you change or bend the light as it goes through the lens. So the condensor lens makes the arc appear to be at the focal length of the fresnel, even though it is not. Take a look at the sketch I posted earlier. The outside lines, are the most extreme rays that make it to the the fresnel. If you follow the one from the arc w/ condensor location, it gets bent by the condensor lens, and becomes the new ray going towards the fresnel, but from the point of view of the fresnel lens, the light appears to be coming from the point at its focal length.
The whole point of the condensor is to allow more of the light from the bulb to end up at the fresnel, and it does this by bending the light that would normally miss the fresnel in towards it. So again looking at the sketch, the interior angle of the triangle for the point without the condensor is 23.4 degrees, so without a reflector, 47/360 = 13% of light from the arc hits the fresnel. The angle from the condensor arc position is 37.5 degrees, so 75/360 = 21% of light hits fresnel.
Hope this helps.
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