DIY LCD Projector - Parabolic Reflector Tests
The tests and corresponding images found here took place on a 32 page long thread that I wrote over at LumenLab. I have moved the images and organized the information learned into this page. Please bear in mind that this is a lot of work and it may remain unfinished.
Now as there was a lot of ideas that were discussed and tried, the tests were broken into two main divisions. On-Axis with a Perpendicular Bulb and On-Axis with a Parallel Bulb. There is one more category not labelled and that is Parabolic Reflection with an Off-Axis Bulb. This latter category actually applies to all the Parabolic Tests, you just simply have to "blackout" the light you would not see if the Reflector was setup in an Off-Axis light engine.
- Standard Light Engine
- Parabolic Light Engine
About the 18" Parabolic Reflector Used
The Parabolic Reflector used for these tests was purchased from Edmund Optics. Unfortunately for me, other suppliers such as Edmund Scientific's wouldn't ship to Canada, or suppliers such as Boreal Laboratories would ship to Canada but they didn't stock the size I had wanted. This led me to having to pay a hefty price from Edmund Optics aswell as hefty UPS shipping & brokerage charges. If you shop around you can get one cheaper than I paid.
The manufacturer who makes these Parabolic Reflectors for Edmund Optics makes them in three different sizes.
| Diameter: | 12" | 18" | 24" |
| Focal Length: | 3" | 4.5" | 6" |
| Center Hole: | 0.75" | 1.13" | 1.5" |
All of them are made of 0.4" thick aluminum which has been coated with a slighly roughed mirror type coating. You could always buff these reflectors or even sand them before having them re-coated if you want a more reflective surface, but as they are they work great. They are reflective enough to see images in the reflection but at the same time they are imperfect enough to difuse or scatter the light a little. I believe this works to our advantage as we do not have a perfect "point" light source.
Continued here.
Topic Navigation Menu
- Standard Light Engine Tests
- Parabolic Light Engine Tests
