I do have a sticker on ours that came from Rosco, giving the following decamired equivalents for their light filters (please note that this is several years old, prior to their reformulation of their booster blue filters, so I don't know whether it is still valid, haven't checked it:)
LB Index-- +167= Full CTO -131= Full Blue +131= Sun 85 - 68 = Half Blue + 81= Half CTO - 49 = Third Blue + 40= Quarter CTO - 30 = Quarter Blue + 20= Eighth CTO - 12 = Eighth Blue + 12= UV filter
CC Index-- +3 = Tough Quarter Minusgreen -2= Tough Quarter Plusgreen +6 = Tough Half Minusgreen -5= Tough Half Plusgreen +13=Tough Minusgreen -12= Tough Plusgreen
Hope this is useful.
The listing Wade gave on the CML is useful with the older Minolta Color Meter II that had a very short range in the green-majenta from +13 to -13, making it difficult to fine tune the green shift of a light.
The newer meter, the Minolta Color Meter IIIF, has an expanded green-magenta scale. The data for the Rosco Gell conversion for this newer meter is listed below:
Rosco Cinegel LB Light Balancing Index +167 Full CTO -131 Full CTB +131 Sun 85 -68 1/2 CTB +81 1/2 CTO -49 1/3 CTB +40 1/4 CTO -30 1/4 CTB +20 1/8 CTO -12 1/8 CTB +12 UV Filter
CC Color Compensating Index 8M 1/4 Minusgreen 5G 1/4 Plusgreen 15M 1/2 Minusgreen 13G 1/2 Plusgreen 30M Full Minusgreen 37G Full Plusgreen
The idea being that you read the light with the meter, then take the two readings, say for instance +80 in the LB incex and 14M in the CC index. You then consult the table on the back. A +80 in the LB index indicates that you place a 1/2 CTO on the light and the 14M indicates that you also place a 1/2 Minusgreen on the light. The Minusgreen gell is magenta colored. (don't get me started...)
After having placed these gells on the light, you should be able to read the light with the meter again and achieve a near zero reading which indicates that the light is now "neutral" for the type film that you preset in the side of the meter. (Type B, Type A or Daylight)
Anyway, you cut and paste the above raw data into your word processor, reduce it to something that will fit on the back of the Color Meter head, and then you have a ready reference of what gell to tell the crew to put on different lights to make them neutral, or whatever.
Bill Bennett email@example.com