Message
Recomendations for optimum room lighting when calibrating moniter
2007-03-19 by CDTobie@aol.com
In a message dated 3/18/07 3:52:05 PM, mkraus1044@... writes:
I am designing a new workroom where I will place my computer and
moniter. I use Spyder Pro 2.2 to calibrate my moniter and PrintFix Pro
2.1 for my profiles. Any suggestions on preferences for overhead
and/or room lighting which would help in the most reproducible and easy
calibration. At this point in time, I could put in pretty much what I
want. Flouresecent vs incandescent, color temp, etc.
The first consideration is consistancy. Yes, daylight is a wonderful thing that makes us happy and healthy; but it is incompatable with serious image editing. You need a room with no window light, or a dead minimum once the blinds/drapes whatever are in place. And the blinds/drapes need to be neutral, they can't be glowing purple or orange!
Next is luminance level. If you are not using a proofing booth, then overall room lighting needs to be correct for the brightness of your monitor. You don't want to be using your monitor at full brightness; so it will remain capable of the same setting over time, and won't burn out prematurely, as well as to obtain a reasonable calibration. So no higher than 175 candelas on the monitor, with something in the 125 to 150 range being the most reasonable choice. Then you can use Spyder2PRO's ambient light feature to measure your room light and tell you if its too much, too little, or about right. Basically, if it seems somewhat dim, that would balance with a bright LCD, is it seems fairly dim, that will match with a moderately bright LCD, and if it seems dim, that would balance with a dim LCD or a bright CRT. If it seems like a cave, then you have managed standard CRT levels. If you are using a proofing light, your ambient can be dimmer, but doesn't have to be. Don't fall into the trap of using a totally dark room and a bright LCD, that will cause glare and percieved contrast increases that will ruin your print to screen match.
Next is ambient light color: something in the 5000k to 6000k range is best. Something resembling full spectrum (CRI of above 90) is best. But your monitor is enough brighter than the room (if you follow the instructions above) so the monitor, not the ambient lighting, will define your eye's whitepoint.
Next would come proofing lights, but its a topic unto itself so I'm leaving it for last, I'll cover room color next. Munsel gray paint gets a lot of airtime; but its TOO DARK for most people's taste Kodak gray card gray, on large wall and ceiling areas is quite opressive!). So get some light gray paint samples from your paint store, use the spot measure function of PrintFIX PRO to measure each sample, and chose the one with the smallest a* and b* values. This will give you a light gray paint for the room. If you want to use a darker gray below the wainscott line (chairrail) then thats good too, and battleship gray floor paint is great for slabs.
But all of this paint colors stuff is ignored by many users. If you ignore it, then at least go to the efforts of hanging a large piece of neutral gray fabric behind your monitor(s) so that there are not bright colors biasing your eye while looking at the monitor. Ditto for the viewing box if you use one.
Guess that brings us to the proofing light issues: get a 5000k proofing light of some type, and set it up; ideally perpendicular to the monitors, not directly beside them. If you proof under room light, then follow these directions using the location where you place prints to view them. Put idential B&W test image prints on both whitened and unwhitened sheets of paper in it (one sheet Entrada Natural, one Entrada Bright, is good). If your box does not offer luminance adjustment, make sure its at least a bit brighter than the room lighting; meaning the paper looks dimmer, not brighter, when you withdraw it from the box. Compare both prints to the same image in Photoshop softproofed to one paper, then the other paper profile (paper white and ink black checked, BPC unchecked).
Which appears brighter; the monitor, or the print? How is the midtone brightness, and the shadow detail. If you have an adjustable box, you can work with that control, if not, you have to adjust the backlights on your LCD until you have the right balance. If you adjust using the monitor backlights, then next you need to recalibrate at your new white luminance level, and define that as your target whitepoint for future calibration as well. If you have another monitor, it gets set to this same white luminance target as well.
Is that complicated enough? If not, you can fuss around with the difference between the whitened paper proof, and the unwhitened one.
As for room lighting to install: you won't need much, so use what you like. In a typical office, I have to loosen three out of four bulbs in the overhead fluorescent fixtures to get lighting down to even a moderate level, the highest level that can be color managed. Consider having two levels of lighting available: general (for vacuuming the floor, finding your glasses, etc...) and color managed (with just the lights needed for appropriately dim ambient lighting).
C. David Tobie
Product Technology Manager
ColorVision Business Unit
Datacolor Inc.
CDTobie@...
www.colorvision.com
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