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After not having to much joy with the CC40 filter on my 5500 I am going to try a glass diachrotic in the lamp housing...


Tycoondog has reccomended a rosco B*stard Amber but is there a scientific way to choose this or simply eyeballing it ???
 

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You're not saying what you're trying to do.


40% is a lot (of whatever it is), if that's how they do their model numbers. Usually a red 20-30% is used (to enhance reds by reducing blue and green) for better color and contrast.
 

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scientific (colorfacts)


I'm not burnt!
 

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PP,


I've had good results with the Bast*rd Amber dichroic in the lamp housing as well. Easy to do, just slide it in. Doesn't affect the external appearance, either.


There is a scientific way, but it gets really involved pretty quickly. First, you find the peak luminances for each primary (this does NOT mean all the way at max.), then use multiple regression to determine the brightest value for a specified chromacity point (like D65) based on the constraint of the maximum luminances of the primaries. Finally, from the two values, use multiple regression again to solve for the optical adjustment to get from solution 1 to solution 2.


In more understandable terms, you can calculate the amount to adjust Red, Green and Blue to optically filter it correctly. What we found was that the solutions were very similar from one 5500 to another. Unfortunately, there are 2 solutions. One is better at fixing the coloration of the blacks (a red/green (yellow) "blue-blocking" filter), the other is better at maximizing contrast (a reddish "green-blue-blocking" filter). Clearly, we want all Red to pass (it's in both solutions), and want a compromise amount of Green also. This perfectly describes the Bast' Amber filter. It's a light salmon colored filter with just a hint of yellow that's perfect. Plus, the dichroic glass filter fits right in the lamp housing.


Thank Simon for finally finding the filter. Thank me for wasting a wad of dough on other random pieces of glass and plastic looking for it :D.


Mark
 
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