One more parameter
One thing you left out: What size image are you going for? Lots of people try for 100" diagonal, but that might just be a bit too big for a 250 Watt lamp. Smaller is brighter. You should measure the wall (or screen area) you plan to use in both vertical and horizontal directions. Then we can figure out what you can use from 12 feet to get that image.
Lilliputs and PSones are both small format LCDs, but they are very different in terms of price and resolution. Do you have the $$$ for a Lilliput 800 by 480? Much more than a PSone, but also much higher quality.
One thing you left out: What size image are you going for? Lots of people try for 100" diagonal, but that might just be a bit too big for a 250 Watt lamp. Smaller is brighter. You should measure the wall (or screen area) you plan to use in both vertical and horizontal directions. Then we can figure out what you can use from 12 feet to get that image.
Lilliputs and PSones are both small format LCDs, but they are very different in terms of price and resolution. Do you have the $$$ for a Lilliput 800 by 480? Much more than a PSone, but also much higher quality.
im not overly greedy 90" is fine thats still what 7' diag?
ok, so it depends on HOW the lens is used as to the source being the parallel in to cone or the source being the Cone in to parallel out the focal point is still the same messurement 220mm from lens to Cone point for a 220mm lens
doing snoopy dance.😀
ok, so it depends on HOW the lens is used as to the source being the parallel in to cone or the source being the Cone in to parallel out the focal point is still the same messurement 220mm from lens to Cone point for a 220mm lens
doing snoopy dance.😀
PSone projector
DIYprojectorCompany.com has a lens you could use. It has a focal length of 217.6 mm to 229.5 mm. Using a 5" LCD from 12 feet, this would give you a 79 inch image on the screen.
With that size image, a 250 Watt MH lamp would be fine. The distance between the LCD and the projection lens will be around 231 mm. I would recommend a 200 mm fl fresnel 10 to 15 mm before the LCD, and a 220 mm fl fresnel about 15 mm after the LCD.
DIYprojectorCompany.com has a lens you could use. It has a focal length of 217.6 mm to 229.5 mm. Using a 5" LCD from 12 feet, this would give you a 79 inch image on the screen.
With that size image, a 250 Watt MH lamp would be fine. The distance between the LCD and the projection lens will be around 231 mm. I would recommend a 200 mm fl fresnel 10 to 15 mm before the LCD, and a 220 mm fl fresnel about 15 mm after the LCD.
cheaper lenses
Here are some cheaper copy lenses that would also work:
210 mm fl 50 mm diameter $10:
http://www.surplusshed.com/pages/item/l2095.html
210 mm fl 50 mm diameter $10:
http://www.surplusshed.com/pages/item/l3311.html
5" LCD from 12 feet would give you an 82" image.
Here are some cheaper copy lenses that would also work:
210 mm fl 50 mm diameter $10:
http://www.surplusshed.com/pages/item/l2095.html
210 mm fl 50 mm diameter $10:
http://www.surplusshed.com/pages/item/l3311.html
5" LCD from 12 feet would give you an 82" image.
ill most likly pic up one of the lenses you recomend, but i was wondering if projection TV lenses work too, like these
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=5750227360&ssPageName=STRK:MEWA:IT
got these for 19.99 shiped. figure at worse use parts for condensor lens infront of bulb.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=5750227360&ssPageName=STRK:MEWA:IT
got these for 19.99 shiped. figure at worse use parts for condensor lens infront of bulb.
CRT projection lenses
Usually they have such a short focal length that you have to put them right up against the CRT or LCD. That means the lens has to be at least as wide as your LCD. This may be possible with a 5" LCD. I guess you will find out!
The lenses may be acrylic, which would melt if you tried to use them as condensor lenses.
Usually they have such a short focal length that you have to put them right up against the CRT or LCD. That means the lens has to be at least as wide as your LCD. This may be possible with a 5" LCD. I guess you will find out!
The lenses may be acrylic, which would melt if you tried to use them as condensor lenses.
yeah, thats what i thought, well, i got one Hipgear 2.5lcd controler comeing 24$ and one PSone screen new sealed 35$ and went ahead and grabed one of the lenses you posted
http://www.surplusshed.com/pages/item/l3311.html 15$
Ill be grabing the LightEngine parts nextweek from work when my electrician coworker comes back (think i have him hooked on the project too)
think the only parts left are reflector behind bulb, mirror to bounce light to fresnel (cold or hot?)
UV and IR filters
Idea's?
http://www.surplusshed.com/pages/item/l3311.html 15$
Ill be grabing the LightEngine parts nextweek from work when my electrician coworker comes back (think i have him hooked on the project too)
think the only parts left are reflector behind bulb, mirror to bounce light to fresnel (cold or hot?)
UV and IR filters
Idea's?
mirrors & filters
If you want to bounce the light off it, then it has to be a cold mirror. The only reasonably priced cold mirror I have found is surplusshed's $5 4.75" diameter cold mirror. All the rest I have found are much much more.
Hot mirrors are much easier to use, since you can fit a small one into a straight light path. There are also lots of sources for cheap and not-so-bad hot mirrors.
For UV filtering, you can buy UV filter sheets at some of the DIY projector web stores for <$10, or you can just use Lexan XL10 to support your fresnels. Lexan XL10 is sold at Home Depot as window glass replacement and has a great UV blocker built in.
If you want to bounce the light off it, then it has to be a cold mirror. The only reasonably priced cold mirror I have found is surplusshed's $5 4.75" diameter cold mirror. All the rest I have found are much much more.
Hot mirrors are much easier to use, since you can fit a small one into a straight light path. There are also lots of sources for cheap and not-so-bad hot mirrors.
For UV filtering, you can buy UV filter sheets at some of the DIY projector web stores for <$10, or you can just use Lexan XL10 to support your fresnels. Lexan XL10 is sold at Home Depot as window glass replacement and has a great UV blocker built in.
hot & cold
Yes, that is how hot and cold mirrors work. But you don't really need both. If you put a good hot mirror across the light path, then you don't need a cold mirror. You could use a first surface mirror (or even a standard mirror before the LCD), which is much cheaper than a cold mirror. (Also you have to keep in mind that every mirror will lose about 10% of the visible light. )
On the other hand, if you can actually fit a cold mirror in the light path, and find one you can afford, then that has some real advantage over using a hot mirror: You get to direct all the heat to the area behind the cold mirror, where it can be absorbed by a heatsink and then removed by a fan.
In my projector, I use hot mirror to bounce the IR back toward the lamp, and I use Lexan XL10 to support my fresnels which acts as a UV filter.
Yes, that is how hot and cold mirrors work. But you don't really need both. If you put a good hot mirror across the light path, then you don't need a cold mirror. You could use a first surface mirror (or even a standard mirror before the LCD), which is much cheaper than a cold mirror. (Also you have to keep in mind that every mirror will lose about 10% of the visible light. )
On the other hand, if you can actually fit a cold mirror in the light path, and find one you can afford, then that has some real advantage over using a hot mirror: You get to direct all the heat to the area behind the cold mirror, where it can be absorbed by a heatsink and then removed by a fan.
In my projector, I use hot mirror to bounce the IR back toward the lamp, and I use Lexan XL10 to support my fresnels which acts as a UV filter.
Ok, got my 210mm lens from surplusshed, and 2 unlabled fresnels
still waiting on my PSone LCD,
Got my Hipgear 2.5" LCD controler but havent found a slideprojector to my liking yet. cant see spending more then 10$ on something im going to gut anyway. but then, ill find somthing.
I still have the 3 projectionscreen lenses, any ideas on tap for them?
still waiting on my PSone LCD,
Got my Hipgear 2.5" LCD controler but havent found a slideprojector to my liking yet. cant see spending more then 10$ on something im going to gut anyway. but then, ill find somthing.
I still have the 3 projectionscreen lenses, any ideas on tap for them?
hip gear 2.5 lcd & OHP not working
I am a newbie and was trying to project a stripped 2.5 lcd from a hip gear onto a OHP Porta Scribe G-100, that has a 600 w halogen bulb.
It's not showing much on the wall , I can barely see an image.
Am I doing something wrong? or is this OHP simply not powerful enough in terms of lumens? I am awaiting to get an old projector slide to try in into but in the meantime, I wanted to see the results on the Porta Scribe.
Can anybody help? I am also waiting for a 15 inch Benq fp557s, that I will strip and put on the OHP. Will it work?
Thank you all for your input
JF
I am a newbie and was trying to project a stripped 2.5 lcd from a hip gear onto a OHP Porta Scribe G-100, that has a 600 w halogen bulb.
It's not showing much on the wall , I can barely see an image.
Am I doing something wrong? or is this OHP simply not powerful enough in terms of lumens? I am awaiting to get an old projector slide to try in into but in the meantime, I wanted to see the results on the Porta Scribe.
Can anybody help? I am also waiting for a 15 inch Benq fp557s, that I will strip and put on the OHP. Will it work?
Thank you all for your input
JF
Are you masking around the LCD? If not this would be the cause, you'll be loosing too much light. You also need to have it right in the center of the fresnel.
Clinton
Clinton
wow a 2.5" on an overhead? i would think you would need to build a stand to raise it about half way just for the lens to see it.
terrible idea
Think about it: Your OHP lights at least a 100 square inch area, but your LCD has only about 3 square inches. So less than 3% of the light output even gets to the LCD to begin with!
Then the LCD absorbs 50% of the light because it has the wrong polarization. Then the color filters absorb about 66% of what is left.
If you blow it up to more than a 15 inch image, I bet it is so dim you can't see it at all.
It makes much more sense to start with a slide projector if you want to use a 2.5" LCD.
Think about it: Your OHP lights at least a 100 square inch area, but your LCD has only about 3 square inches. So less than 3% of the light output even gets to the LCD to begin with!
Then the LCD absorbs 50% of the light because it has the wrong polarization. Then the color filters absorb about 66% of what is left.
If you blow it up to more than a 15 inch image, I bet it is so dim you can't see it at all.
It makes much more sense to start with a slide projector if you want to use a 2.5" LCD.
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