How to make a Diffuser for your HID

stollman

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HID Spotlights are great for lighting up far away objects, but they are also a great portable source of light that can be used in photography and videography. Most spotlights have a shiny reflector that gives off lighting artifacts (i.e. rings), that can be seen in a picture or in video. To eliminate this effect and create a smooth light pattern, a Diffuser is used. Some HID manufactures provide a Diffuser accessory which includes a Rubber Hood and a Diffusing Glass (most do not, though). The use of a Diffuser will reduce the total lumen output of your light, which is an unfortunate side effect.

Examples of Rubber Hoods:
Battery Junction L35----------Oracle 35W

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Hoods have a groove to accept a Diffuser

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Diffusers sold by manufacturers are made of a special glass or plastic that can withstand high temperatures over an extened runtime. Most often, they are "frosted" like this one for my L35 from Battery Junction (seen below). If does a good job in smoothing out the light pattern.

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The home made Diffusers I will be discussing are made of plastic, and are much less resistant to heat. I would only recommend using them on the light for a short period of time. The one I made for my Oracle 35W light holds up well against the heat generated by the bulb, and I have used it for up to 15 minutes without issue. Using an 80W HID like the Barn Burner, or the Mule, is a different story. After about 5 minutes, these powerful HIDs start heating up the Diffuser and the melt-down process begins. Whatever HID you are using, I would experiment to see how well the Diffusers hold up against the heat before you use them in the field.

The following thread discusses how I made Diffusers for my HID lights.

Tools:
* Black Permanent Marker
* Pliers
* Scoring Knife
* Epoxy Glue (holds up well against heat)
* Hot Melt Glue Gun
* Dremel with Router and Grinding Wheel Accessories

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Materials:
* Clear Lexan Sheet - Lowes/Home Depot, Window Department. Lexan is rigid and holds up well against heat. It provides a good base for the Diffuser Material. DO NOT use Acrylic, which does poorly against heat and has certain flammable characterists

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* Flourescent Light Diffuser Material - Lowes/Home Depot, Lighting Department. This material is brittle and thin, but it does a great job in diffusing light. It will be glued to the Lexan, which provides the base.

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Build Time:
* It wil ltake about 30 minutes to build a Diffuser

Build Cost:
* Materials should be less than $15.00

Steps:
Before you Begin: Make sure you have all your materials and tools readily available

1. Trace Lexan Shape
* Sometimes you can buy Filters for your lights, which can be used as a template for tracing the cut-out image on the Lexan. If not, you'll have to "wing it". If it's not perfect, you can always use the Dremel and Grinding Wheel to clean up the shape.

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2. Cut out Lexan Shape
Use the Dremel and the Router Accessory to cut out the shape. Take your time!

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3. Trace Diffuser Shape
* Using the Lexan shape, place it on the smooth side of the Diffuser material and trace out the image.

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4. Cut out Diffuser Shape
* This is the hardest part. This material is very brittle.

* The Dremel/Router does not work well for cutting out the shape. You might try a Dremel with a cutting wheel, but I have not tried this.

* The best way I have found is to use a scoring tool on the smooth side of the Diffuser material, and cut in many fracture lines. Then, place the shape on a flat surface, so that the desired fracture line is located at the edge of a table. Use the pliers to carefully break away material at the fracture lines. Since this material is very brittle, it is not uncommon to go through 3-4 shapes until it finally comes out right. This process can be a little frustrating.

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5. Trim Shapes
* Use the Dremel and Grinding Wheel to smooth out the O.D. of the Lexan and Diffuser shapes.

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6. Glue The Shapes Together
* Remove (peel off) the protective covering from the front and back of the Lexan shape.
* Using the epoxy, glue the two shapes together
* Allow the expoxy to set before going to the next step.

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7. Smooth out the O.D.
* Once the two shapes have cured, use the glue gun to lay a thin bead around the O.D. to give it a smooth edge. This will also help keep dirt from getting in between the two shapes.

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8. Install Diffuser in Rubber Hood

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YOU BE DONE!


What do I do if the place where I bought my 35W HID flashlight (i.e. Ebay) does not sell a Rubber Hood?
* Most 35W flashlights have common bezel dimensions. There is a good chance the Rubber Hoods sold by AE Light or Oracle (Advanced Automotive Concept) will fit.

What about large HIDs that don't have a Rubber Hood?
* Xevision and Battery Junction sell a nice Diffuser for their powerful HIDs. The one for my Barn Burner, which is the same as the L70 Locator, is great.

* For those who have made a HID from a Thor or some other Host, this may work for you. I made the following Diffuser for my 80W Mule. I glued some metal washers onto the front of the light with epoxy. I then glued some small magnets that I found at Jo-Ann Fabrics onto the Diffuser. The magnets do a good job holding the Diffuser to the light. The offset of the magnets also provide a small air gap to help disipate heat between the front lens and Diffuser. Note: Since these bigger watt lights put out a lot of heat, don't leave the Diffusers on for an extended period of time.

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Final Comments:
* Though frosted Diffusers do a great job smoothing out the light pattern, they do reduce the lumen output. It is my opinion that the Diffuser material I use lets more light out, yet stills does a great job smoothing out the light pattern. The flourescent light diffuser material is similar in design to that of the Barn Burner/L70 Diffuser.

* Once you get done using the Diffuser, remove it from the light and let the light cool down before you pack them both away. If you leave the Diffuser on the light and immediately stow the light in a backpack or duffle bag, you will most likely be emotionally distressed when you go to retrieve the light. A HID flashlight stays hot for a long time after you turn it off, and when you pack it away in a confined space, you enhance the effects of the heat. This will cause the plastic Diffuser to melt and possibly the Rubber Hood. There is also a good chance the light may get damaged too. This situation happened to me once. Luckily my BB survived without injury. The Diffuser, however, died a painful, warped death.

* Besides using flourescent light diffuser material, you can also use Glad Press N' Seal. While still using the Lexan shape for a base, cut out a shape from the shelf-adhering Press N' Seal and apply it to Lexan Shape. This material should not be toward the lens side when mounted. It does a good job in smoothing out the light pattern, similar to frosted glass. I would not recommend putting the Press N' Seal directly onto the lens of the light....it would probably melt.

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The End.....
 
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