By Stan Sholik
If the number of products available to pre-capture white balance digital cameras is any indication, professional photographers’ interest in creating a neutral color balance must be very high. There is a good reason for this of course. While professional digital cameras do an excellent job autofocusing and autoexposing, auto white balance is not likely to give accurate, consistent color under many ambient lighting conditions.
White balance isn’t that much of an issue when making RAW captures as it is easy to adjust when processing the files, though it adds work time. When capturing in JPEG, or RAW + JPEG formats, it is important to have as accurate and consistent color as possible to reduce additional processing and saving of the compressed file.
With prices ranging from $8 to over $100, I thought it would be interesting to test a few of these white balance filters under actual ambient lighting conditions to see if they produced an accurate white balance and to examine the advantages or disadvantages to each. One of my photographer friends swears by Mr. Coffee filters for white balancing, and I was curious to see if he was really serious! My store was out of Mr. Coffee brand but had Melitta Junior Basket filters in stock, so I picked up a pack for testing.
Along with the Melitta, I tested five filters designed for professional photographers: the ClearWhite, ExpoDisc Neutral, Lally CAP, Mennon and Phoxle SpectraSnap. Designers of each of these photographic filters took a slightly different approach, and one approach or another might influence your decision as much as the accuracy of the white balance.
The standard ClearWhite filter is a 4-inch square with a small hole drilled in one corner for the supplied neckstrap attachment. One side of the filter is a 1/8-inch piece of diffused white plastic while the other side is a 1/16-inch piece of black foam with a 2.5-inch hole cut from the center. You hold the foam side against any lens with a diameter up to 95mm and make an exposure to set the white balance. I felt a little silly walking around with it dangling around my neck, and it’s a little too large for pockets, but it stores compactly in a camera bag when it isn’t needed. MSRP is $49.95 and it is available from www.DigitalPhotographyKits.com.
Most photographers are familiar with the ExpoDisc from ExpoImaging. In the interest of full disclosure, it is the filter that I have used since it became available. The round ExpoDisc consists of a prism-textured plastic disc on one side and a plastic diffusion disc on the other. Sandwiched between the two are color correction filters. I use the 82mm model and simply hold it in front of the lens with the prism side facing the primary light source. ExpoDiscs are available in various sizes from 52mm (MSRP $69.95) to 95mm (MSRP $169.95) from www.ExpoDisc.com. They also include a neckstrap that I don’t use, but the 82mm fits easily in a pocket.
The Lally CAP takes a unique design approach. It is a piece of gray fabric with elastic sewn into the edge. The Lally CAP slips over the front of your lens (up to about 100mm diameter) and stays in place while you make the white balance exposure. You need to remove most of the ‘flower-petal’ lens hoods in order to use it, but it can be slipped over the lens hood of other lenses. What I really liked about the Lally CAP was slipping it off the lens and just stuffing it into a pocket until I needed it again. It is available from www.LallyPhotography.com/store for $29.95.
There are many variants of the Mennon white balance filter sold under other names but all look and cost the same. It is made in China and consists of two pieces. One piece screws into the filter threads of your lens and the white plastic diffuser snaps on. It is sold as a white balance lens cap that can remain on your lens for protection when the lens is not in use, but I set aside the threaded section and just held the diffusing piece over the lens. Filters are available from 52mm to 77mm for about $5 on eBay.
The Phoxle SpectraSnap is a flat white disc with notches holding a removable blue rubber band. I removed the rubber band and simply held it in front of my lens. It too is pocket sized, but seemed to scratch a little more easily than the others. The scratches seemed to have no effect on its operation however. It also comes with a nice soft black fabric bag that I used to store it between tests. There is only one size of the SpectraSnap available and it is suitable for lenses up to 120mm in front diameter. MSRP is $59.95 from www.phoxle.com.
The giant of the group is the Melitta filter, measuring over 6 inches in diameter and large enough for a 300mm f/2.8 lens. Available at supermarkets in packs of 200 for about $2, I had a hard time taking it seriously at first.
I tested in three different challenging lighting conditions. First was in the morning fog to see if the white balance filters would deliver a neutral gray fog. Second was on an industrial assignment using only the plant’s available light. This consisted of 4000K, 65 CRI lamps about 30 feet off the floor, large skylights and open roll-up doors. Finally I shot in late morning inside a church lit with the new compact fluorescent bulbs in overhead fixtures with light streaming in through stained glass windows. At each location I did my white balance exposure with the lens and filter pointed at the main light source, then captured a JPEG of the scene.
The original captures are reproduced here…
In each lighting condition, the Auto white balance of the D3 gets you somewhere in the ballpark, but not to a neutral. In the church series, the Auto white balance is far too warm, while in the fog and industrial series it is too cool. The ClearWhite nailed the fog and industrial tests, but, as with all the filters, is a little cool in the church. Closest to neutral in the church and providing the most accurate visual match is the ExpoDisc, which also delivered a very neutral fog scene and was only slightly warm in the industrial capture. The Lally CAP is consistently cool in each of the conditions although it does a pretty good job with the fog. The Mennon also was consistently cool, but pretty close in the industrial shot. The Phoxle SpectraSnap was cool in the church, but nailed the fog and was only slightly cool in the industrial setting.
But the surprise of the test is the Melitta. It delivered a perfectly neutral fog and was slightly cool in the others, but no worse that most and better than the Lally CAP and the Mennon!
To pick a winner, I’d say, with the conditions tested here, it’s a tossup between the ClearWhite and the ExpoDisc. But in a pinch, stop by a supermarket and pick up a bag of Melitta Junior Basket coffee filters.