Working under Mercury-Vapor Lights

As you know if you read my blog regularly my favorite way to set my white balance is to do a custom white balance setting using the ExpoDisc. Here is a quick reminder–skip down if you want to see another way to set your white balance.

Remember under fluorescent and mercury-vapor to set the white balance at shutter speeds of 1/100 or slower. You can later shoot under faster shutter speed after custom white balancing the camera.

ExposDisc goes in front of the lens and then you use it to get an incident reading rather than a reflective reading of the light.


Notice the direction of the light hitting the subject.  You move to the same position to get the light reading below.


Point the camera toward the direction of the light that is falling on the subject.

The latest upgraded version has introduced the warming filters that you place in front of the ExpoDisc. They are light blue and since the camera tries to neutralize the colors will add yellow to your photos thus warming them up. the actual color is really a blend between cyan and blue adding a little red/yellow to your photos. They come in different densities to allow you to add just a little or more depending on your taste.

Presets in Nikon D4

Check your manual for your camera because this is for the Nikon D4. Somewhere in your menu you can go and adjust using presets for white balance.


On my Nikon D4 in the menu for White Balance you can choose up to seven different presets for fluorescent.  There is a major problem I have found trying this method, it isn’t easy to pick the right color, because the monitor on the back of the camera isn’t that easy to see color in all situations.

Fluorescent lamps are manufactured to a chosen color by altering the mixture of phosphors inside the tube. Warm-white fluorescents have color spectrum of 2700 K and are popular for residential lighting. Neutral-white fluorescents have a color spectrum of 3000 K or 3500 K. Cool-white fluorescents have a color spectrum of 4100 K and are popular for office lighting. Daylight fluorescents have a color spectrum of 5000 K to 6500 K, which is bluish-white.

Note that on the Nikon D4 you also have a pre-set for those awful Mercury-Vapor lights. Sometimes I have found that I prefer one of the fluorescent settings under some of the newer mercury-vapor lights when using this system instead of the custom white balance.

White balance 2.0: Saving even more time in post production

I just recently upgraded my ExpoDisc. The upgrades come with the Portrait Warming Filters.  This little addition is saving me more steps in Adobe Lightroom and giving me more time to enjoy life.

I have been using the ExpoDisc since 2005. ExpoDisc was invented by George Wallace to help his students at San Jose State to get better exposures with Kodachrome 25.  He studied with Ansel Adams and Minor White where he learned to master the zone system.

I wrote about how to use the ExpoDisc a while back, but here is the basic idea of how it works.

ExposDisc goes in front of the lens and then you use it to get an incident reading rather than a reflective reading of the light.


Notice the direction of the light hitting the subject.  You move to the same position to get the light reading below.


Point the camera toward the direction of the light that is falling on the subject.

The latest upgraded version has introduced the warming filters that you place in front of the ExpoDisc.

In Adobe Lightroom in the Develop Module you can adjust the color temperature and this is where I often would warm up my photos. 
Now I no longer need to do this. I now am using the +1 warming filter which introduces just a little warmth into all my photos. 
The cool thing is if you don’t want to do this for any reason you don’t have to use the filter. If you want it even warmer then just use the +2 or start stacking the filters.
The Auto White Balance [AWB] setting on your camera is looking at the scene in front of the lens and then it will read all the color it sees and will try and make it 18% gray.  So if you have a red wall you are photographing the camera will all cyan to make this red wall appear gray.
If someone is in that photo then their skin will have a cyan color cast. 
The problem with 18% gray cards is depending on the angle you hold them you can get a glare which will shift the camera color settings. I have found that every other system I have tried that uses reflective light reading [you point the camera at the device] is not as accurate than when the camera is put into the light making an incident reading.
The second benefit of the newer ExpoDisc V 2.0 is it comes with a carrying case. When I first bought my ExpoDisc years ago it came in the standard filter case like all other filters you bought. This new case you can put on your belt if you like and have it readily available.
When I first bought my ExpoDisc I paid more than $120 for the device. Today it comes with more options and only costs $49.95.  
If you consistently use the ExpoDisc I promise you that you will notice a consistency in skin tone with all your images that will make people notice. 

Custom White Balance vs Presets

Custom White Balance using ExpoDisc

Today I shot the Wreaths Across America Day event at Roswell Presbyterian Cemetery.

While shooting this I realized many folks assume those presets for white balance will give good enough results. Well sometimes they do. They will put you in the ballpark for each type of situation.

Auto White Balance 

Now you maybe satisfied with Auto White Balance. The point here is notice it is different than the custom white balance above.

It was raining and they really don’t have a rainy preset.

Cloudy Preset

While the cloudy preset is closer I think it is a little too orange.

Daylight Preset

Even the Daylight preset is different.

Shade Preset

I think the Shade Preset is the closest, but still some minor differences.

The latest version of the ExpoDisc 2.0 comes with warming filters. They are slightly a cyan color of different densities to let you pick how much you want to warm up your image. So without them you get a pure 18% grey and by adding these you warm up the photo just a bit.

You just put the warming gel in the front of the ExpoDisc and then take your reading. This way you can keep a consistent warming to all your photos.

So what should you do?  I would advise always doing custom. You can always change it later using Adobe Lightroom if you shot it RAW.

To the left here is the pull down menu that is available to you in Adobe Lightroom if you shot it RAW. These are very similar to the presets on your camera.

Sometimes the perfect custom white balance maybe not your preference in the end.

Just click on the link below to see more of the photos from Wreaths Across America Day at Roswell Presbyterian Cemetery.