Why Calibrating a Screen is not Enough to Create an Art Photograph
To correctly create an art photograph, the calibration of a computer screen is essential for the development phase.
Correct calibration of a screen is the guarantee that the photos will be viewed in the same way on another calibrated screen from anywhere in the world.
As we wrote in another article, an artistic photograph exists only on paper whether for a wall display or for a beautiful book. Displaying on a computer screen, tablet or mobile phone is only an intermediate step that is not essential to us. To correctly print an artistic photo, the calibration of a screen is insufficient.
Calibrating a Screen is the First Step in the Development Process
As we mentioned in the article dedicated to the development of an artistic photograph, the use of software is essential for a photographer to show his vision of the world through his photographs.
But before using software, it is essential to properly calibrate the screen that will be used during the development process.
If this step is not done correctly, the development of colors, tones, contrasts will not be good.
Why Calibrating a Screen
Screen manufacturers produce devices that are often very bright, very contrasting. The photographs displayed are often cold. Indeed, photographers are a very small minority. Most screen users just play games, visit websites, or use desktop applications. The original settings are made to satisfy these users.
But a photographer has other more specific needs because his photographs will be printed. When a photographer edits a photograph, he wants to be able to display colors, contrasts and tones correctly. For example, he does not want exuberant colors as tablets know how to produce. It is most certainly flattering to the eyes, but they are incompatible with a quality paper printing.
For this reason, it is necessary to calibrate the screen. Colors, contrasts and tones will be displayed relative to standard values.
The Principle of The Calibration of a Screen
To properly calibrate a screen, it is necessary to use a calibration device. A calibration with eyes will not give a good result because it will be subjective.
A calibration device is a small electronic device sold by specialized companies. It connects to a computer via a USB cable. It is displayed on the screen for the calibration phase. It comes with a special application supplied by the manufacturer. It is he who will control the probe during the entire calibration phase.
At startup, the photographer will enter some very simple data, perform one or two operations. Then the software will drive the probe for calibration.
When all operations are complete, the application will generate a file called an ICC profile that contains the characteristics of the screen.
This ICC profile will be loaded by the operating system of the computer at each startup. This profile will provide information to the video card to correctly display colors, contrasts and tones.
The goals of correct calibration are:
- Neutralize the default settings of the constructor of a screen.
- Display a correct level of contrast and brightness in the widest range of colors possible.
Take the example of the gray in the gamut RGB has the value 128. If the screen is calibrated correctly, it will display a true gray. If the screen is not calibrated properly, the gray will shoot the orange.
Why Eyes Do Not Allow a Good Calibration
As we have just described, a calibration device is necessary to properly calibrate a screen. The human eye is not adapted to this operation. On the one hand, he is not able to read a color without having an element of comparison. On the other hand, he is not able to know the brightness level of a screen. Even when the light is low, it can detect details in a scene. If a photographer observes a dark picture on a screen, he will be able to see details. He will think that the tones are correct. This is when the photograph will be printed that that he will realize that shadows or blacks are deep.
Calibration in Practice
Calibrating a computer screen has become quite easy. The application editors have made very great progress in the ergonomics and software interface.
The first step in the data. The photographer will fix the color temperature, the gamma, the contrast value, the maximum brightness, which is also called the white point.
Once these values are provided in the calibration device application, calculations will be performed for a few minutes. This step is called characterization. At the end of the process, the application asks for a name for a data file. This is the famous ICC file that we mentioned earlier. It will be loaded each time the computer starts.
One of the essential points for an art photographer is to fix the amount of light emitted by the screen between 80 and 100 cd / m2 (candelas per square meter). A higher value will cause problems at the time of printing.
Once a screen has been profiled, one also says characterized or calibrated, the settings must not be modified any more. If this happens, it will be necessary to redo a calibration.
We recommend performing a full calibration every two week as the settings change themselves. These are not great variations, but quality developments need to be perfect from the beginning to the end of the post-processing chain.
Proper Calibration is Not a Guarantee for Correct Impressions
Correct screen calibration only ensures that the photos you develop will be viewed in the same way on all screens around the world that are properly calibrated.
If you use another way to view your photos such as a video projector or printer, you may be very disappointed with the result.
Take the specific case of using a printer. As artistic photographers, this is the way we use the most to show our work.
If you do not do anything after developing an art photograph with your calibrated screen, we can bet that your photo will be dark. Indeed, paper absorbs light while a screen emits light.
When printing an art photo, it usually lacks between 1 and 2 EV of light. Shadows are often clogged. The whole photograph becomes flat.
If you have a personal printer, it is essential to calibrate it. So, the result will be consistent with the one you have on the screen.
The problem comes from impressions made by specialized laboratories. You cannot intervene in the printing process. You cannot calibrate the printers.
In addition, if you use the services of a general laboratory, you will not be sure to have your photographs printed by the same printers with each order. This is a real problem because you cannot create a rule for brightness management and apply it every time you want prints. It is totally unpredictable.
For this reason, we always use the services of specialized laboratories with whom we can discuss directly. We can learn the brands of printers as well as the printing procedures.
But in both cases, whether it is a specialized laboratory or a generalist, it will be necessary to increase the light of the photograph to print it correctly.
The problem is how much EV you must increase the light. Too much value may cause overexposure of certain areas. A low value will still give a picture too dark.
It is for this reason that one must ask for tests by asking a proof. It is a test of your final prints. The printer selects a portion of the photo and sends it to you for verification. This process should be repeated as many times as necessary. The proof is often paying but it is interesting because once the photo printed and against glued on a support, the cost is quite high.
We will not go into detail to print an artistic photograph. This will be the subject of another article.
The correct calibration of a screen is the first step for the development of art photographs. But it is insufficient if the photographs are to be used for other media such as a projector but especially with a printer. Another process must be initiated for the printed photo to be properly displayed. A photographer who wishes to perform artistic prints must absolutely worry about this crucial phase if he wants to highlight his photographic vision.