DIY Video Projector

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#1,941
I agree with Timtimes.

Just take the project one step at a time. If you think that you can just get a diagram and put the thing together you are mistaken. Right now it is all trial and error. Read the posts, dexide how much you want to spend, set up a budget (i.e. I will spend $XXX for a light then I will save and spend $XXX on a panel......)
It may take a while to complete but the anticipation is half of the fun.

And you should try switching to decaf!
 
#1,943
CRT route

Finally got a reply from the university in regards of the "Brightness boosting" of CRT but it whas chort and far from comprehensive.

They simply told me I could reduce the voltage on the catod instead of boosting the votage on the anod . . . .

This is more simple than boosting (incresing?) but I would like some opinions on this so Scot_lad or any one else, if You have the time, please post Your opinions!

Bye for now
 
#1,944
CRT is the way i would love to go. I was amazed to even get an image from my f2.8 slide projector lens just held in front of my monitor (on 100% brightness and contrast 🙂 ) i got a 4" image and i could read every word.

This is quite i bit more dangerous than LCD though i imagine. All the static **** and the electrons it gives out. I'm hesitant to take a monitor apart in fear of electrocution 🙂

Very interested to know ppl are still trying this route.

cheers,
 
#1,945
hayabusa light

im trying to find exact details but my busa bright headlight has a really nice reflector and a ?magnifier? (whick was a half sphere) in front of it in which it really light up the area in front of me all the way down the road as far as i could see - at least a mile. bike headlights might be better than cars because cars rely on 2 points where bikes only use 1. this bike is also made to go extremely fast also thereby needing a longthrow light.

so far all i can find is
headlight 12v 65 +55/55w
not sure if for regular or bright or both lights
should i snap a pic with the digital camera?
 
#1,946
Wow! the optics in this slide projector are great. A very reflective reflector -> large condensor lens -> UV Filter -> Double convex -> objective lens.

This projector came with a large, about 5 filament halogen (500W). It wasnt particurly bright, and was no more that 3000k (but that doesnt bother me much. You could see the filament on the screen when focused. For my testing i'm using an old black and white laptop lcd, i could easily focus to get a VERY sharp image, i could see every pixel and read every bit of text on an area of about 4 foot (until it started boiling up and went yellow for a few mins till left to cool) This suprised me a lot considering it was in daylight.

I ordered an A1/239 (ANSI code EVD) quartz-halogen today, which will be much more fitting for the reflector. I really have high hopes for this one. 16000 lumens (which is good cos im getting a small lcd, not a ohp one) 36v (if this projector works i will be using a microprocessor to control it as if it was a real projector (OSD etc) so 36v means its safe and can be servo-driven) 400W (ummm, nice!) i will try to post some pics tomorrow. I took some of the slide projector but they came out too dark (Kodak DC20, kodak's first digital camera! literally!)

Cya,
 
#1,948
here are 2 pics freshly taken of the head light. you cant really see much but the front lens. the top light (regular light)might be good for a reflector but not nearly as bright and would need to be diffused also but it does spread the light around the bike.
 

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#1,951
Zoom function

On my Quantum OHP it has this projection lens.
An externally hosted image should be here but it was not working when we last tested it.

is this lens made out of 2 lenses and currently my screen is HUGE and i want to make it about half the size that it is now if i take the lenses out and move them further apart will this make for a longer throw and reduce the screen size? Please excuse my n00bness in optics.
 
#1,953
Greetings

Hello everyone,

Just introducing myself, I have been lurking for a couple weeks reading all the posts...heh that took awhile.

Anyways I just wanted to thank you guys for having created this great forum.

I decided to start out with the "poor mans" version of a projector and bought an nView Spectra C LCD panel, and a Elmo 305A Solar Deluxe OHP from those guys at Inventory Solutions. It arrived today and I have spent the last hour playing around with it. I was quite surprised at how nice it looked without me doing much of anything to enhance the image.

This is a picture of the output, taken with my cheapo digital camera, in partial darkness, on a plain wall painted "off white" color. Hopefully this will work.
Projector Sample

Now I need to fine tune things, and get that Parkland Plas-Tex screen built. Will post some more pictures when I get that done.

Later
 
#1,954
Marklar,
in a patent database i have found an invention, that claims to have a simple solution for that problem. It is suggested to attach two additional lenses at the objective of an conventional OHP.
First lens concave, f= -310mm
Second lens, convex, f=+1000mm.
If the first lens is attached at the entrance of objective and the second at the exit, this should double the throwdistance of projector and therefore halfen normal image size at a given distance.

does this help?

xblocker
 
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