Chromaticity experts will address questions from the pressroom, plate room, prepress, workflow, proofing, digital photography, and color management. Submit a question by going to www.chroma-tech.com and choosing the trial question option. Please make sure to note that you are submitting a question for Newspapers & Technology.

Q: I have one query about the image on PCs and Macs. In my understanding, due to the different gamma values of PCs and Macs (PC, 2.2 and Mac, 1.8), if we open the same image on a PC or a Mac, we can see that the color looks different. What can I do to make the image look the same on both platforms. Do I need software or can I just adjust the gamma value or white point?

A: The goal of color management is to describe how devices reproduce color so that applications such as Adobe Photoshop can use that information to make the image preview look accurate.

First, you need color management software and a colorimeter to first calibrate and then build an ICC profile of each monitor.

Next, you will need software that uses these profiles to make the two systems simulate color in the same manner. Photoshop is one such application. Photoshop will use these profiles to make an image appear the same on both a Mac and a PC.

It is advisable to calibrate all of the monitors in your workflow to the same white point and gamma. You should ignore the Mac and PC labels and use settings that give you the best match of monitor to proof. We recommend starting with a white point setting of 6500K and a gamma of 2.2 on all of your systems unless you find that a different setting works better for you.

Although the ICC profiles that you build for each monitor will do the best job they can at matching images from monitor to monitor, you have a better chance of obtaining a closer match if all your monitors are calibrated to the same standards.

Mike DiCosola
mike@chromaticity.com

Q: When generating digital photography, what is the difference between gray balancing, white balancing and profiling?

A: Many of the procedures required for producing quality digital photographs are fundamentally the same as those used to produce traditional film-based photography.

Where the two differ is after composition, lighting and exposure are set. It is at this point that a procedure known as gray or white balancing needs to be performed.

Gray or white balancing is essentially the same thing. It corrects the image for a color imbalance caused by variations in the color temperature of the light source.

Aiming the camera at a white or neutral gray card in order to “teach” the camera what neutral is under those particular lighting conditions performs the balancing process.

This task ensures that neutral areas of the image remain neutral. Theoretically, if neutral areas of an image are neutral the other areas of the image will maintain their color accuracy. That’s theoretical because there will always be color inaccuracies that will require correction or retouching, regardless of whether you use a digital or film camera.

Most of these inaccuracies can be prevented, however, through the careful and consistent use of white or gray balancing.  Profiling means creating an ICC profile for the camera. ICC profile generation for digital photography can be a complex and frustrating experience because of all of the variables involved. Gray or white balancing is usually a simple procedure that should always be used if your camera allows it.