Lighting Your Workspace

October 24th, 2008 | Categories: Workflow

The lighting conditions in your work area can greatly affect the quality of your work. Do you know whether or not your workstation lighting conditions are ideal? This article aims to explore the requirements and recommendations for proper lighting conditions when working on a computer workstation and viewing printed images. I’ll explain how I setup my home office workstation to get the best balance of monitor viewing light and print viewing light. Unless you are a professional working in a tighly controlled (and calibrated) lab environment, it will be difficult to exactly meet the standards requirements for both monitor viewing and print viewing at the same location. I definitely do not in my office. But I think I’ve achieved a very nice working environment that sufficiently satisfies both needs.

The "proper" viewing conditions are defined in a few standards. They are ISO 3664:2000 and ISO 12646. Both establish viewing-conditions standards for computer image editing facilities. The difference is that ISO 12646 is much more stringent and aims primarily at pre-press color professionals. In addition, the ANSI PH2.30-1989 For Graphic Arts and Photography – Color Prints, Transparencies, and Photo Mechanical Reproductions – Viewing Conditions standard also provides guidelines for workspace lighting. By looking at all of these standards one might be able to assess a set of recommendation for a decent workspace lighting solution for digital photographers in a home based workspace. The official title for the standard is ISO 3664:2000 Viewing Conditions — Graphics technology and photography. Official copies of the standards are available from www.iso.org and www.ansi.org, for a price. It would cost a couple of hundred dollars to get all three standards, but that’s not really necessary. A litte net research will uncover the relevant details.

I’ve been using a color calibrated workflow for quite some time on my monitors and printers but have basically neglected the room lighting. However, with my recent upgrade from a ColorVision Spyder (1st Gen) to a GretagMacbeth EyeOne that was capable of reading ambient lighting tempertures and levels I became accutely aware of how far from ideal my working conditions really were.

When I first put my home office together (in one of the spacious10′x10′ bedrooms in my house) I installed low voltage halogen track lighting on the ceiling with a mix of floods and spots to light my work area. The work surface is a neutral gray laminate 10′x8′ U-shaped desk. I thought the halogen bulbs would provide me with plenty of nice white light to work in. As it turns out there was plenty of light, too much in fact, and it wasn’t even close to the right kind of white. This picture (it is and old picture, with my old Dell computer, before I built my new computer) shows basically what the office lighting looked like.

I installed a dimmer for the track lighting but it makes such a loud humming sounds that I never actually turn it down from full power because it found it too annoying. The very yellow lights under the desk are cheap $6 under counter flourescent lights that I use when I need to get back behind the computer or run cables. It’s normally off, but extremely handy when you need light in tight spaces.

The EyeOne Match 3 software has an option for measuring the ambient lighting. When this option is turned on, the calibration wizard includes a step to allow you to measure the ambient lighting in your work area. The EyeOne Match software also spells out in the helpful sidebar what the ideal lighting conditions should be, including mentioning that the ISO 3664 standard specifies guidlines to these conditions. The first time I took an ambient reading I was confronted with this result:

Those little black bars are supposed to be positioned near the center of the green bands. My reading was taken by placing the EyeOne puck near the center of my monitors. According to the EyeOne software wizard, I was supposed to see about 5000K for a color temperture and about 54 Lux for the illuminace. I was actually shocked at how far off I was. Both gauges were pinned at the extremes. I was off the scale! Oh the humanity. I had been working in these conditions for almost two years.

And thus began my quest for proper lighting conditions.

What are the proper lighting conditions? Well, according to ISO 3664:2000 the proper conditions for image editing and viewing on a monitor are (in summary):

Ambient light white point should be CIE D50. This standard generally means that the white point should be about 5000K with a generally even spectral power distribution (full spectrum lighting). This is an ideal. Not many light sources provide this ideal solution.
Ambient light illuminace should be 64 to 32 Lux in the area of the monitor.
Monitor white point should be D65, or approximately 6500K.
Monitor illuminance should be 75 to 100 cd/m^2.

For print viewing, ISO 3664:2000 adds:

High level viewing illuminance of 2000 +/-500 Lux (for "critical" evaluation and comparison).
Low level viewing illuminance of 500 +/- 25 Lux (to simulate normal viewing conditions).
Extraneous light should be blocked from view and from illuminating the print.
Directly illuminated surfaces should be a neutral gray.
Other lit colored surfaces in the field of view should have a reflectance of 60% or less.

Using the greatest questing tool ever invented I quickly identified several resources that purported to have high quality full spectrum lighting solutions, including this article from the Lighting Research Center at my alma-mater (I don’t think it existed when I attended almost 20 years ago). The article mentions that Dr. John Ott essentially invented the science of full spectrum lighting. He co-started a company called Environmental Lighting Technology Inc. who’s subsidiary, Ott-lite Technology, sells Ott-Lites. They do, however, charge a premium for their product.

I spent a fair amount of time researching the different manufacturers of full spectrum lighting to see if I could find a more affordable solution. One company, Solux, was selling replacement bulbs for my track lighting fixtures for about $5.00 per bulb. Another, FullSpectrumSolutions, sold flourescent full spectrum bulbs, similar to Ott-lite, but much less expensive. Spending some time on both websites revealed to me that both of these sellers were engaged in a war on each other to discredit each others products. See this and that. I decided to take a second look at Ott, figuring that Dr. Ott spent over 40 years researching lighting and these other companies were primarily interested in discrediting each other. The Ott-Lite website is just a generally nicer experience. That counts for something in my book.

I remember reading an article on The Luminous Lanscape where Michael Reichmann talked about using an Ott light for print viewing. The lamp the Michael describes is a small portable unit that wasn’t going to provide much ambient light in my office, but he liked it for looking at prints (though he uses a different, more expensive solution now).

I few minutes of browsing on the Ott-Lite site revealed that they have a product called the TrueColor FlexArm Plus Lamp that looked like it would make a nice light source in my office. It’s MSRP is $169.99. That’s quite a lot for a desk lamp. I spent a few days looking for the best prices on these lamps. In the end, I buy two of these desk lamps from a JoAnn Superstore for 50% off with some coupons. I took two trips because I could only use one coupon per day. If you’re not familiar with JoAnn, it’s a large chain of fabric/sewing/craft stores. It turns out that these lamps are extremely popular with the sewing and quiting crowd because they allow the artisans to precisley match fabric colors. JoAnn also sells them online for a good price.

I bring my light home and installed them. This is what my workspace looks like now:

The wall color in the room is a very warm cream color, but they receive so little light from the desk lamps that the viewing conditions are not significantly affected.

I have the lamps on my desk, one on either side of my monitors and positioned them such that the ambient lighting in the area immediately in front of the monitors measures out to 54 Lux and 5400K using the EyeOne.

In addition, the print viewing areas on either side of my monitors measure out at 582 Lux and 5400K using the EyeOne.

Both sets of measurements are very close the reccomended conditions laid out in the ISO and ANSI standards:

White point of D50, I get 5400K
Ambient lighting in the montior area (32-64 Lux), I have around 61 Lux.
Print viewing light at 475 to 525 Lux, I have about 580 Lux.
Monitors are both calibrated to 6500K, gamma 2.2 using the EyeOne Match 3 software/hardware.
Monitor illuminance is set to 140 cd/m^2 as recommended by the EyeOne Match 3 Software.

The monitor illuminance differs from the ISO 3664:2000 standard which recommends 75 to 100 cd/m^2, but is more in line with the more stringent ISO 12646 standard which recommends 80-120 cd/m^2. Most LCD’s today are much brighter than even 120 cd/m^2. Adjusting the gain (contrast) on the LCD can have negative effects on its ability to accurately render continous tones, especially in the shadow regions, since this adjustment is usually implemented in the panel as a gain control either in the front end ADC (for an analog connection) or in the back end (for a DVI connection). In both cases the RGB data is being scaled from full range 0-255 to something less and this scaling will cost you in image quality on the display because you will not be using all 256 levels available. Some higher-end LCDs offer a backlight control that allows the brightness to be turned down by lowering the intensity of the backlight itself. This is the more preferable (but much rarer because it’s more expensive to implement) solution because it does not reduce the 0-255 data range.

It’s probably better to err on the side of too-bright than the cripple the LCD panel. CRT’s should not suffer as badly from reducing the gain (if needed). I’ve been using LCD’s for 6 years now, and can’t imagine ever going back to a CRT no matter what anyone says about them being superior. I don’t play my music on vinyl either.

Updating the lighting condition in my office has made a huge difference in my perception of the images both on screen and in print. With the calibrated monitors and the proper lighting conditions I have very closely matching images. The full spectrum lights really do make prints look better and easier to judge for fine tonal gradations.

Now I think I need another Ott-lite to place over my Epson P4000 so I can watch my prints being printed in perfect lighting condtions. I’ll have to keep my eye open for another coupon at JoAnn.

And finally, here is a panoramic picture of my digital photography studio. This picture was stiched together from 19 images shot with my Canon 10D camera using the 17-40 f/4L @ 17mm. I used a Nodal Ninja panorama head and stitched the panorama using PTGui. The picture makes the studio look larger than it really is. The room is 10′ wide by 12′ deep. I had the tripod backed into the closet to maximize my coverage of the room.