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Description:
This Java applet simulates the RA4 color negative printing process widely used to make "C" or "Chromagenic"
prints. Learning this process the traditional way can be time-consuming and expensive, so an alternative
was envisioned to replicate it using digital image files and realistic controls.
Every color negative has unique characteristics and will respond differently to the same enlarger settings.
To simulate this variation, this program generates random values for the "correct" yellow and magenta
filtration and exposure each time a new image is loaded. The control settings are initially set at 75 yellow,
50 magenta and 8 seconds -- a generic starting point -- and the user must adjust them to arrive at the "solution"
and match the example provided.
PLEASE NOTE: This applet simulates the PROCESS of color printing only,
it is not intended to provide the functions of true image editing software. Depending on the quality and
characteristics of the image files loaded and your system's hardware components, the "correct" versions of
the images loaded may or may not appear perfectly color balanced on your monitor screen.
Instructions:
1. Select an image by clicking on one of the icons on the top of the screen. There are several sets of
images supplied with this applet and you can use the "next" and "prev" image group buttons
to navigate them.
2. After the image has been loaded, your task is to make the "test" image in the right panel match
the "correct" image in the left panel. To do this, use the scrollbar controls below the images
to adjust the yellow and magenta filters and the exposure time. You can also change the f-stop
to adjust the density of the image.
3. Once you've made a color correction, click the "expose" button and you should see the test
image change in color and/or density. Experiment with different settings and adjustments and try
to get as close as possible to the image in the right-hand panel.
4. After you've made several tests, you might want to go back and forth among them to see the
results of each change you made. You can easily do this by clicking the "next test" and "previous test"
buttons.
5. To see the "correct" color balance and exposure time, click the "solve" button. The controls will
scroll to the correct positions and the image will be updated.
Using the "hints" features:
Color printing is a subtle art and it can be very difficult to get the test print to perfectly match the "correct"
one. This program provides two ways to see if you're getting close without using the "solve" button:
Checking the "hint when correct" box will cause the yellow, magenta and time labels to change color
when an exposure is made with their values correctly set. To see what this looks like, load an image,
check this box and click the "solve" button.
Checking the "hint when close" box will cause the yellow, magenta and time labels to PARTIALLY
change color when their values are within 5 points of the correct values and change color
FULLY when their values are set correctly.