Dichroic coatings

Maintenance Of A Lighting System That Uses Color
First of all you will always be required to perform maintenance of some sort no matter what color medium you employ. What this means is you should NOT continue to pay for the same unit in the same location with the same color to be recolored on a weekly basis. With a dichroic filter that has higher transmission you will not have to replace it once a week or even once a month. This is due to the material's ability to tolerate heat. The required general maintenance of a dichroic filter is a wet cleaning with a mild glass cleaner, isopropyl alcohol or warm soapy water.

What Does This Mean In Terms Of Savings:
1) Less time spent cutting and installing GEL.
2) Less Inventory.
3) Fewer phone calls to order color.
4) More time and funds to spend on other projects.
5) Smaller lamps which frees up power to add more fixtures without a power upgrade.

The initial investment into dichroic filters appears high but in the long run the investment will pay for itself in terms of the savings listed above as well as the other savings you will discover along the way.

Color Consistency: The ability to produce consistent color from batch to batch and year after year is quite an art. We are looking to establish the color standards for this medium and we plan to do so by defining the acceptable tolerances for each color manufactured.

Quick Color Education:
The human eye is an incredible apparatus for discerning color differences. Unfortunately, not all of us see color the same way, in fact recently optical biologist have proven that mans geographical location and his heritage have quite an effect on how he perceives color which effects true focus and depth or depth cueing. With this in mind parameters have to be set that will check for the consistency of color from filter to filter. We do this by defining each color numerically. There are two systems used based on a four quadrant system defined by (C.I.E. 1976) L*a*b* or (C.I.E. 1931) values. These systems allows us to define the area of an ellipsoid. The size and shape of each ellipsoid changes as you move from hue to hue. Blue is the most forgiving in terms of shift in hue and chroma and has a uniformed color space. Green on the other hand will allow for a greater shift in chroma and less shift in hue, therefore, the shape of the ellipsoidal becomes oblong and not a perfect circle. Basically, green does not have a uniformed color space.

This approach to color matching allows us to offer the same type of consistency you get when you buy Gel. There will always be some difference from run to run no matter how precise new technology in thin film gets. The question is will the human eye accept these differences as being the same. By offering color this way you can now request your filters to be within a specified color area. Of course the tighter the tolerances the higher the cost. When ordering dichroic filters you will find three categories of color to select from: CF1, CF2, CF3. The "CF" means commercial factor with one being the tightest tolerance and three the widest. The "CF" system is a relatively new system that is now being used by most thin film manufacturing companies to help standardize the ordering process.

When you buy at CF1 color uniformity and repeatability are important. If you buy two CF1 filters, red, in January and you need to add three more in March you have now allowed yourself to receive three more filters, off the shelf, that will match very closely to your first two filters. CF1 pertains to a stock line of color that you may purchase in most sizes and shapes on a regular basis. CF1 is also how we categorize a custom color match. If you reference a polyester number as the desired color for a dichroic most manufacturers will come as close as technology and finances allow .

Your Request May Fall Into The Following Provisions:

1) A custom design fee may be requested paid in full prior to any design work.
2) A manufacturer may or may not provide you a sample or samples, in a reasonable size, for you to evaluate the color. Usually you will not see a sample until the manufacture feels they have a suitable match. or you may be given a written guarantee that the color will match the color within a specific tolerance with a rejection period to return the parts for replacement. Once a sample or color tolerance contract has been approved, manufacturing will begin. If the client should request the same color at a later date, NO design fee will be incurred.

Some manufacturers may have a grading system for the color tolerance and commercial factor of their for their dichroic color. It is always a good thing to ask so there are no surprises when you receive your order.

We have now covered how to decide what each color media is best for, what is a dichroic, what categories you may specify a color under, custom color matching and the characteristics of a dichroic. The next bit of information is very important to placing an order for a dichroic filter.

When Requesting A Quote For Dichroics Please Provide The Following Information:
1) What is the Color? Reference a Commercial Standard Dichroic number, or a match to any of the Gel's that are commercially available, Lee, GAM, etc.
2) What size, in inches or millimeters. A cutting tolerance and edge quality need to be stated, otherwise We will produce at our standard cutting tolerance of +\-1mm with a swiped edge.
3) What type of fixture is being used, include the lamp type / wattage and operating kelvin temperature.
4) If the filter is being used outdoors, please outline the environment, for example, it will be used with a 500 quartz lamp submerged in water. With this type of information we can determine if our standard product is adequate or if a modification is required.
5) What is the temperature on the lamp side of the filter and how long will the filter be exposed to these conditions?
6) How will the filter be mounted? Is there room for expansion?
7) What is the maximum thickness for the filter?
8) What is the beam angle of the reflector? What is the distance from the filter to the reflector?
9) What is the time frame required for delivery?
10) Will the client accept partial delivery?

These are some very important questions that should ALWAYS be asked when a dichroic filter is being requested.

A Dichroic Filter Is NOT The Perfect Color Medium
1) It is Glass and it will Break if it is NOT properly handled or Installed.
2) It is sensitive to Beam Angle. From approximately 38 degrees and greater you will experience a phenomenon called "Color Fringing" or Halation. This effect gives you a Spectral Breakdown of the Target. For example a Green filter will take you through ***Pink, Magenta, Indigo with the peak beam finally rendering Green. Some Designers will actually mock up different colors to specific reflectors to create graduated color washes for exterior Architectural applications.
3) COSTS. It is not an inexpensive product to get into, however, based on the total investment in the long term you must ask your self "How much more do I want to continue to spend on service?"