Hello I am here again. I promised to work in one redesign of reflector for my proyector and now I will show my results.

I have analyzed the way that works the lamp without reflector. In this manner alone takes advantage of the light that impact directly in the fresnel lens.

If I utilize a reflector of ½ of sphere, recover the rays of light that impact on the reflector, a disturbance of light is produced on the filament of the lamp, same that is observed on the diagram as a semicircle.

If I Utilize a reflector of complete sphere, recover the rays of light that impact on the reflector, a disturbance of light is produced on the filament of the lamp, same that is observed on the diagram as a complete circle.

Other pic

I have built a new reflector, I as show in the following image. I built it using two hemispheres of steel, and joining them so that a sphere be formed. Leave a spice interval to achieve the spherical form.

Other pic

I Cut in front of the sphere, a circle (window) calculating the sufficient area, by where the ray of light leaves that the area is required to cover of the fresnel that interests myself.

Other pic

When I lit the projector, I observed with happiness that the shine on the screen was increased in a notable way.

Can you post a picture that shows no reflector, helf spherical, and full spherical so we can compare the difference.

Scott

Please look this section:

http://www.lumenlab.com/forums/index.php?showtopic=1965

Its very hard to tell with different image sources and different distances the photo was taken at.

pretty interesting, but i would be nervous about that duct tape being on the reflector as i'm sure the reflector will reach pretty high temps and perhaps catch fire...

I agree with you, it is difficult to show with photographies the increase of sheen. I can say to you what I observed directly, it was an increase of sheen. I will try to obtain an exposure meter to measure the increase of sheen. Regards

Do not worry. The reflector is of Steel and the heat does not preserve. Also I covered the groove with aluminium, which also does not guard the heat. And covered the aluminium with a aluminium color tape. My system of cooling works very well. I have proved the projector for more than 6 hours of constant work and it does not warm up. Regards

What is the contrast radio of your LCD.???????

Great improvement.

I have not found information of the contrast of the PSone, if anybody knows a direction where me it could report, please give it to me. The only known information is in the following direction:

http://www.bit-tech.net/article/136/

These are other photos where it is possible to look that the whole light of the lamp goes ahead, at all towards the sides, not up and not at all at all down.

Passed alone 1 minute of which the lamp was activated.

Other pic

Nice job GRA_PELAYO! given you're using such a small, low-res screen.
Interesting to me is your reflector design, especially the use of two hemispherical bowls to achieve a sphere - looks like those flat-bottom shinny $1.99 stainless steel bowls from WalMart would do the job(in this case).
My question to everyone is, what do you think about the full-sphere light reflection design as opposed to semi-hem we use today? I know GRA has used it and says it works better, but any thoughts on why it would work better?

My intention is to be useful near 100 % of light that generates the lamp. My design and its principles, I try to present them in the first photos of this topic and like I have written, my results are that it improved the sheen of the screen that I project. I will try to obtain an exposure meter to be able to evaluate exactly the obtained result

My hemispherical bowls do not has a flat-bottom

Yea, but one would still cut off the flat bottom just like you ended up cutting your non-flat bowls to get both ends of the lamp to fit in, is that right?
Thanks

For more accuracy in the spherical form, I preferred using not flat bottom bowls

Looks good. What is the diamerter of the bowls and where did you get them? Have you tried moving the arc slightly out of center? That may permit more light to bounce out of the hole.

Good work.

Diameter is 16.2 cms. I bought it in a store that sells spoons of steel for kitchen, was a spoon of 900 ml. Thanks by your suggestion, seems Me correct

I found a fotometro and I have measured the difference of light obtained with double hemisphere and with simple. I found a minimum differentiates, for which I consider: For the moment is sufficient to utilize a single hemisphere. I will continue seeking a better solution.

Actually it is a bad design by nature, Brain has the ultimate design using the light bulb and given design, I talked to the people who make bulbs and by their accounts, by causing a disturbance of light you shorten the life of the bulb by almost half or even more. Lightwaves start bouncing back inside the bulb and cause vibrations as well. It is not good practice to enclose those bulbs to that extent. On the other hand , it is to be commended for reaching out to new goals and experimentation.
Thanks
MastahScott

I found a fotometro and I have measured the difference of light obtained with double hemisphere and with simple. I found a minimum differentiates, for which I consider: For the moment is sufficient to utilize a single hemisphere. I will continue seeking a better solution.

can you tell me what dimensions and what bulb and ballast you are using ?
Which lcd? the 4 inch one that is in the psone monitor?
thanks
MastahScott

I´m using:

EYE LAMP M400SX/BT28/HOR

M59 Standard 400W Multi-Tap, Metal Halide Ballast and a mogul Socket

I´m using this LCD:

If it is true. The half ball design (norpro) or any spherical reflector will cause the same problem too.
Since the efective good reflection area is very small. Pehaps is better, instead increase, cut down the reflector area to save the time life of the bulb.
Or even better, create a virtual point light, pehaps with Ellipsoidal Reflectors and condense lens.
Is it possible or I'm smoking too much?

Now I moved my lamp backward of the center of the bowl, also I have observed a small increase in the measurement of resultant light on the screen