Technical Service Document 61 - 11/97

STARLITE 55 SOFTWARE UPGRADE VERSION ST31197

Starlite 55 Colorhead is supplied on a 32-Pin EPROM chip. This version adds the following features to those of the previous versions.

 Improved Filtration-to-Density Correction:

Filtration-to-Density Correction automatically increases or decreases the Starlite lamp power to compensate for varying filtration. Previously, this was left up to the operator of the Starlite. This new version of this feature is designed for use with BBS brand Video Analyzers and Translators.

 Self Test Routine:

The Starlite can now perform most of the steps described in the Technical Service Document "Manual Control Test Diagnostic," automatically. This is useful in finding problems with the Starlite’s mechanical and electronic systems. This routine is accessed at the end of the Starlite Diagnostics menu.

NOTE: If you are upgrading from an older version of Starlite Software, this version may not function properly unless you perform a MASTER RESET function to clear the Starlite’s memory. This action may take place automatically upon installing the new chip. A Master Reset will completely clear all the memory items in the Starlite, including your Master Color Balance, and any Job Memories you may have saved. Please allow some "recovery time" as part of installing this version of software.

Full Descriptions of the new Filtration to Density Correction is described in the following pages. If you have any questions or problems with the new software version, please contact your local ZBE dealer or the offices of ZBE, Inc, at the address and phone number at bottom of page.

Filtration to Density Correction

The Starlite’s Filtration to Density Correction is designed to make the colorhead automatically compensate it’s amount of light output power (D) as you change the filtration (C, M, and Y). This feature is convenient for users who are used to working with "Visual Density" instead of the "Neutral Density" normally utilized by the Starlite.

Users of any analyzers or translators manufactured by Bildsysteme Brugger & Schmerler GmbH (BBS), will require this mode of operation for the Starlite to be compatible with their analyzer or translator system.

Functional Description:

The Starlite’s Filtration to Density Correction simply feeds a portion of each color filtration value into the Density output. These ratios are defined by the user, so that the Starlite’s light output can be matched to the specific machine or system with which it is being used. The ratio for each color is expressed as a percentage (0% - 100%).

This system of correction uses the difference between the current filtration on the keypad and the standard filtration (set during the CALIBRATE MASTER COLOR BALANCE) to calculate the density correction.

Thus, the Filtration to Density Correction uses two sets of data for operation: The Standard Negative (Shirley) Filtration as entered during the CALIBRATE MASTER COLOR BALANCE routine, and the Filtration to Density Correction Gains as entered in the Starlite Calibration Menu ("Edit Filt to Dens Correction Gains") as percentage (%) values.

An Example:

To demonstrate this system, consider an operator that has calibrated his Starlite to make a perfect Standard (Shirley) print at D:60, M:60, and Y:60, to correspond with his BBS video analyzer. In addition, he has entered his Filtration to Density Correction Gains as C:0%, M:50%, Y:25%.

Now that the Starlite is ready for printing, the operator analyzes a new negative, for which the BBS reads a filtration of D:90 M:80 Y:76. When he enters this new current filtration at the main screen of the Starlite, the Starlite computer makes the following computations:

	D:	C:	M:	Y:
*Standard* (Shirley) Filtration (in CC’s): Set when the Starlite was originally calibrated using the CALIBRATE MASTER COLOR BALANCE routine.	60	0	60	60
*Current* Filtration: Entered for printing the new negative.	90	0	80	76
Difference from *Standard* to *Current* Filtration: Calculated by Starlite Filtration to Density Correction	+30	0	+20	+16
Filtration to Density *Correction Gains*: Entered in the Edit Filtration to Density Correction Gains item in the Starlite Calibration Menu.		0%	50%	25%
*Calculated* Correction to Density of light output:			20cc x 50%= +10cc	16cc x 25% = +4cc

Note that the Density value on the keypad will not be changed (it will still be 90cc as entered by the operator), but the amount of light that goes with this value will be +14cc brighter than it would have been without the Filtration to Density compensation. This increase at the output of the Starlite will compensate for the light lost through the filters, keeping the total light energy (Visual Density) the same as it falls onto the baseboard.

Setting it up:

In order to benefit from the new Filtration to Density Correction, the Correction Gains must be set to the proper percentage amounts. Since the effects of filtration (M and Y) upon Density is different for different darkroom setups, you must set these values yourself. Follow the general process below as a starting point.

(f you already know what percentages of Magenta and Yellow are part of Density, you can simply enter these values in the Correction Gains screen of the Starlite as described in step#11 below and in the user’s manual.)

Make a perfect Standard (Shirley) Print and calibrate the Starlite using the CALIBRATE MASTER COLOR BALANCE procedure as described in the Starlite manual. Use the Standard filtration values that are used on your analyzer. (BBS users usually use D:60 M:60 Y:60.)

Analyze a different negative on the analyzer and write down the filtration values. (The further the color filtration is from the standard negative, the better your setup will be.)

Use the filtration values from the analyzer to make a print with the Starlite. The resulting print should be close in color balance, but in error in Density.

Be sure that you write down the Density on the Starlite that you used to make this print.

Change the Density at the Starlite and make more test prints, until the print comes out correct in density. Write down this new Density value.

Subtract the Original analyzer Density (from Step#3) from the Density that made the print correct (from Step#5). Write down this Density Difference.

Subtract the Shirley filtration value for Magenta (Step#1) from the Analyzer Magenta value that the analyzer gave for the new negative (Step#3). Write down this Magenta Difference.

Use a calculator to divide the Density Difference by the Magenta Difference. The result will be a number less than 1. (Example 0.42)

Express this fractional number as a percentage by multiplying by 100. (Example: 0.42 x 100= 42%)

This value is your Correction Gain for Magenta. Of this value (ex. 42), take approximately one fifth of this number and call it he Correction Gain for Yellow. (Example: 42 / 5 = 8. In this case, Magenta Gain = 42% and Yellow Gain = 8%.)

Enter these values in the Filtration to Density Correction Gains in the Starlite Calibration Menu.

In the Starlite Preferences Menu, find the item titled FILTRATION TO DENSITY CORRECTION, and make it ACTIVE. (See users manual for details.)

This procedure is designed as a starting point only. As you analyze and make more prints from new negatives, you will want to make fine adjustments to the Filtration Correction gains.