A alot of people know that for 15 inch lcd, when you have a parabolic shape reflector, the image will be very bright but you will see a terrible hotspot at the center and the center is much brighter than the sides. If this is not an annoyance to you then its good. Pls bear in mind that I use 250w Hqi-tsd. I am using a diy cylindrical shape reflector.
I am not 100% perfect in removing the hotspot but alteast it has been greatly minimized that I am not noticing it anymore when concentrating on watching movies. its kinda dlp projector that when you start looking for rainbows, you will definitely see it and be annoyed.
when I put a spherical cylindrical reflector on top of the parabolic cylindrical reflector. The bulb is at the center of spherical-cylindrical shape reflector. I noticed now that the sides are brighter than the center. And this is what I want. For big lcd projector, the problem always is the sides is dimmer than the center. When you project only a white screen, with lcd off, you will notice the sides is now much brighter
My bulb position is unconventional unlike the others. The bulb length is perpendicular to the longer side of the lcd. This position provides very bright image for widescreen movies. The sides will be brighter than the top and bottom but luckily,the difference is subjectively small and unnoticeable.
This is easier said than done epecially for the parbolic shape as small change in parabola shape will have big change in the reflected light but you'll get it eventually thru persistent trial and error.
I am not 100% perfect in removing the hotspot but alteast it has been greatly minimized that I am not noticing it anymore when concentrating on watching movies. its kinda dlp projector that when you start looking for rainbows, you will definitely see it and be annoyed.
when I put a spherical cylindrical reflector on top of the parabolic cylindrical reflector. The bulb is at the center of spherical-cylindrical shape reflector. I noticed now that the sides are brighter than the center. And this is what I want. For big lcd projector, the problem always is the sides is dimmer than the center. When you project only a white screen, with lcd off, you will notice the sides is now much brighter
My bulb position is unconventional unlike the others. The bulb length is perpendicular to the longer side of the lcd. This position provides very bright image for widescreen movies. The sides will be brighter than the top and bottom but luckily,the difference is subjectively small and unnoticeable.
This is easier said than done epecially for the parbolic shape as small change in parabola shape will have big change in the reflected light but you'll get it eventually thru persistent trial and error.
hello hertz, im from cebu.
I'm planning on giving this one a try for the holidays.
I've got a couple of questions though.
How can I achieve a full 1080p HD projection? Will the 20" sony bravia work? It appears it the smallest( cheapest too ) HDTV available here in the Philippines with 1080p native resolution.
More importantly, can i order from you ALL the necessary parts for this project? Of course I also need guidance along the way, so I'm counting on you helping along a fellow Pinoy. Hehe.
Salamat and great work here!
I'm planning on giving this one a try for the holidays.
I've got a couple of questions though.
How can I achieve a full 1080p HD projection? Will the 20" sony bravia work? It appears it the smallest( cheapest too ) HDTV available here in the Philippines with 1080p native resolution.
More importantly, can i order from you ALL the necessary parts for this project? Of course I also need guidance along the way, so I'm counting on you helping along a fellow Pinoy. Hehe.
Salamat and great work here!
pls email me .
I cant send you email.
20 inch is too big. There are some models of 17 inches in the Phils w/1080p resolution. I ll help you search.
There are alot of used lcd in our local site.
http://tipidpc.com/viewtopic.php?tid=8116
I cant send you email.
20 inch is too big. There are some models of 17 inches in the Phils w/1080p resolution. I ll help you search.
There are alot of used lcd in our local site.
http://tipidpc.com/viewtopic.php?tid=8116
Now i am using commercial dichroic reflector. Junk the diyreflector.
I thought before that 250w is only good for 90 inches diagonal. Now i can say its still very good for 120 inches diagonal image.
looking up the pics above, the image now exceeded the size of my screen.
Here is 120 inches images, Now almost reaching my ceiling. I was really surprised. image quality is still very nice.
The black level still doesnt change that much.
I thought before that 250w is only good for 90 inches diagonal. Now i can say its still very good for 120 inches diagonal image.
looking up the pics above, the image now exceeded the size of my screen.
Here is 120 inches images, Now almost reaching my ceiling. I was really surprised. image quality is still very nice.
The black level still doesnt change that much.
ang galing idol hehe!
I'm really impressed on how you did your DIY Projector
and how you continuously improve its quality sir
Anyway I'm an ECE undergraduate student and I'm currently writing a thesis research paper. Will it be fine sir if I could have you as my consultant to answer some questions related to your DIY projector?
I hope you could help me out sir, Thanks in advance
I'm really impressed on how you did your DIY Projector
and how you continuously improve its quality sir
Anyway I'm an ECE undergraduate student and I'm currently writing a thesis research paper. Will it be fine sir if I could have you as my consultant to answer some questions related to your DIY projector?
I hope you could help me out sir, Thanks in advance
Just got a cheaper HSD bulb with short arc and 250w 6000k.
Image is now as bright or brighter than some commercial projector.
No need to use bigger projection lens actually smaller is Ok just like the varifocus lens because the arc image fits thru the bottom of projection lens.
I have some spare. Just email me if you need one.
Image is now as bright or brighter than some commercial projector.
No need to use bigger projection lens actually smaller is Ok just like the varifocus lens because the arc image fits thru the bottom of projection lens.
I have some spare. Just email me if you need one.
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