Viewing booths
9 December, 2009 by
Viewing booths
Jon Cone
Here's one for you! The viewing booth... These were staple items found in every serious color expert's arsenal of tools. As important as having a correct ICC profile, the viewing booth closes the loop between what you see on your monitor and what you can expect to print. Viewing booths have one purpose. They are used by color experts to make up for deficiencies in human vision during color matching evaluations. Historically, these booths have had a full spectrum 5000k lamp with which to match the white point of calibrator monitors which have also always been 5000k. The viewing booth was situated directly next to the display - the room dimmed - and images which were being soft-proofed could be evaluated to the proof. The viewing booth has special dimmers which allow the booth's illumination to be matched to the monitor without changing the kelvin temp of the light.

It's not arbitrary that 5000k was chosen as the standard. 5000k is actually the white point at which the Standard Observer (average human being) sees white light as being Neutral (having neither more nor less red, blue or green component). At 5000k, a human being can best determine whether two adjacent colors are matching. So the D50 standard was established throughout the printing and imaging and color industries. Nearly all CRT monitors had physical controls with which to match this white point. Several amazing CRTs were released over the years from companies such as Barco, Sony, LaCie and NEC that were designed purposely for D50 color management. Unfortunately, the demise of the CRT ended the ability of the average consumer to produce a great color managed studio in which a display correctly matched proofs and Photoshop worked under 24 bit color. Today only a few LCD displays are actually capable of producing a white point of 5000k. The Eizos which we feature on InkjetMall are two of these displays. We refer to true calibrator monitors as 'reference calibrator displays'. They feature an on-board engine that tunes the actual LCD (or CRT) including its white point. These have replaced the Barcos and Sony Aritisans of yesteryear. These unique displays have an extra port besides the video cable that hooks up directly through USB so that calibration software measuring through the calibrator instrument is used to actually adjust the on board engine of the display. Other displays such as the Apple flat screens and other brands are calibrated using a similar device and software. But, instead of adjusting the display, the computer's video board is adjusted and a lookup table is created. While pundits of modern methods say there is no difference between a lookup table on a video board and a lookup table on a calibrator reference display such as the Eizo - they neglect to mention that the lookup table on the calibrator reference display reduces it from billions of possible colors always to 16.7 million colors, while the lookup table on the video board can reduce the boards output from 16.7 million colors to as few as 7 million. RGB color defined as 24bit is comprised of 256 red levels times 256 green levels times 256 blue levels which equals 16.7 million possible RGB color combinations. Photoshop uses these color combinations to display your image. If the video board is calibrated so that a non-reference calibrator LCD which has an internal white point of 6500k is adjusted to 5000k, the video board will necessarily be outputting much less than 256 gray levels in at least two of its three channels. The downside of this is that using Photoshop to make very fine adjustments may not result in accurate updates to on-screen color. But certainly, the accuracy of a soft-proof ICC profile is greater when displayed through true 24 bit color than reduced throughput color. The majority of 'true' color professionals are using reference calibrator displays and have a D50 environment. The majority of color management gurus however, must necessarily adapt themselves to either their companies or their sponsors or their audience. So most of today's color management presentations concentrate on what the average consumer with an ordinary display can expect by calibrating their video board. Entire industries have sprung up supporting the consumer. ColorMunki and the competing Spyder are selling into this market. These video board calibration packages are really good for the money. But the end-result is not as good as using the same instrument on a reference display.
Eizo CG 222W
There are two camps really. And the professional camp is getting smaller and smaller; does not need to attend seminars, etc...but no longer has to spend $10,000 on a Barco. The Eizo's first were released at about $6,000 several years ago. Today, the 21' Eizo√Ç CG 222W is only $1,399. A slightly larger color space version and 24' Eizo CG 243W is only $2,345. I personally use both - and believe the 222W to be the bargain of the century. For Piezography it is perfectly adequate. The 243W captures more of the Adobe RGB 98 color gamut and is slightly better for those who work in color. However, I do not differentiate between the two when I print with artists working in color or b&w. I choose the bigger display when I am sitting side-by-side with the artist/photographer. Now back to the viewing booth...√Ç Most consumers look at a print under one light source and then look at the soft-proof on their monitor/display which is calibrated to another light source and evaluate whether their color management is working. Very seldom are both of the light sources at the same color temperature (K). Humans are unable to adapt to two different white points. That is to say if a human looks at a sheet of white paper under 6500 k and the same sheet of white paper under 5000k or 3800k, they will not appear to be the same color of white. And when trying to evaluate a color match between colors under two different white points the problem becomes magnified. The proper procedure is to have a viewing booth adjacent to the display with both set to the same white point. 5000k is the standard. But 6500k is also possible for those who would rather calibrate to the native white point of their LCD and must use video board calibration.
For your consideration we have a viewing booth available with a 6500k option... This booth is manufactured in USA by GTI. We've been using booths by GTI at Cone Editions Press since 1992. This booth is reliable, constructed well, and performs well. The dimmer is positioned at the left top near the on/off switch. The cost of the GTI PDV 3e/D booth is $839.00 and you can purchase it by clicking here. There is another version which includes a 5000k backlit dimming transparency viewer at its base, so you can look at a proof, the original transparency and your display simultaneously.
The cost of the GTI PDV 3eTR/D is $1,410 and you can purchase it by clicking here.
Viewing booths
Jon Cone
9 December, 2009
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