Custom White Balance With Flash

 

This should have been the money shot from a recent "Kitten Shower" held by the Peninsula SPCA. I sent two other photos for the Editor In Chief to select from and for some reason this one wasn't one of them, although the more I look at it, the more I wished I had sent it.

The venue featured narrow hallways with yellow walls and ceilings. I made this test shot by bouncing my flash off the ceiling, and you can see the yellow tint on my subject's faces. If the surroundings were painted in a warm color, the added tint might have gone unnoticed, or in the best case, actually improved their coloration. Yellow, unfortunately, gives my subjects a jaundiced look, and technically accurate, but not complimentary.

Now before proceeding, you should familiarize yourself with how to create a custom white balance (CWB) setting. While it may have been a novelty when digital cameras evolved, photographers soon realized that while one such preset would be very useful, the ability to create one for each venue where the lighting varied even the slightest bit. Currently, most cameras have provisions for multiple saved presets. Sure, you can correct this in post production, but by taking a few seconds to establish an "environmentally appropriate" CWB setting, you can save yourself  a lot of time during post production.

Read Ken Rockwell's review here.

White Balance Measurement. When the Expo Disc first appeared on the market in 2011, it gave photographers an easy way to obtain a CWB setting. It was designed primarily for achieving a compromise white balance formula when working with continuous artificial light sources. In use, one would:

• Select the CWB (or equivalent) setting from the camera's menu,
• Set the Exposure Control to A,
• Attach the Expo Disk to the front of the lens,
• Point the camera towards the light source, and
• Press the shutter release.

Internally, the camera would evaluate each photo sensor and adjust the red, green, and blue readings until they were all the same value, yielding a "neutral" baseline for the white balance setting.

Buy yours here.

I gave away my Expo Disk years ago, and experimented with a variety of gray card substitutes as a "target" for creating a CWP value. I finally replaced the Expo Disk with this inexpensive plastic Dot Line White Balance Lens Cap, which works just as well as the three-times more expensive Expo Disk. It could be adapted to serve as a lens cap, as it was made in a variety of diameters from 52 to 77mm. At one time they could be had in 49 and 82mm sizes, but apparently no longer. Since they were so inexpensive, I bought one in every diameter, but in the end, just carried the 82mm size and just held it in place over the lens whenever I needed to create a CWB for the current photographic venue. I keep one of these in all of my "recreational" camera bags, and there should have been one in the "working bag" I carry when on assignment.  I repeat: Should have.

I realized that the disk would have been the only way to properly achieve a  CWB for those pesky yellow walls. As it turned out, the disk was nowhere to be found. I wondered what I would do next, until I found the Dome from my Gary Fong Light Sphere. I now held a perfectly usable neutral diffuser that I could hold in front of my lens while I measured the light bouncing off of those yellow walls. I promptly did just that, and it gave me the proper white balance for all the photos when I bounced my flash off of similarly painted walls

In this historically accurate reenactment, you can see how I held the dome in front of the lens while I made the CWB reading. The forward-facing flash is directed towards the selected bounce surface when the reading is made. In the event of an over or under exposure warning, I will need to adjust the output until I get a proper reading. I rotate the flash head towards the bounce surface when I am actually shooting.

As described, this flash technique should only be used when bouncing off of a reflective surface. If the flash is to be used as a direct light source,  repeat this process while aiming your flash/camera into a convenient mirror. If you're adjusting the flash output manually, you'll need to dial the output way down, select a smaller shooting aperture, or both.

For the technically inclined, this photo was made (obviously) with two cameras: one mounted on a tripod, and the other held in my hand. The key light was provided by a radio controlled speedlight mounted on a light stand just to the left of the camera. A shoot-through umbrella was utilized for the shot. The second flash on the camera in my hand was programmed to respond to the radio trigger of the tripod camera, thus ensuring that it would fire when the tripod camera fired the key light. The fully articulating screen of the Fuji T-4 helped me position myself within the frame. Final cropping gave me the composition I wanted.

Metal Threads For Your Plastic Adapter

As wonderful as the Viltrox 28mm F 4.5 lens is, it isn't perfect. As I mentioned in an earlier post, the lens has has no means of attaching a filter. This could be a big thing because the fixed F 4.5 aperture is pretty wide, and it would be helpful if a neutral density filter could be attached to provide a means of controlling the exposure other than ISO and exposure time. 

A company called Filmatura has addressed to problem my offering an adapter ring that can hold a 52mm filter and slips onto the Viltrox 28mm F 4.2 lens barrel. It is not machined from metal, but is instead created using a 3-D printer using a plastic similar to a weed-wacker cable. And while those 52mm threads can be created with reasonable dimensional accuracy, they are still plastic, and therefore subject to wear whenever a filter is screwed in or out. Cole of Alt Cine Cam suggests that users install a metal 52mm to 55mm step up ring to prevent damage to the soft plastic threads. 

Buy yours here.

Now 55mm accessories are not as common as those in 52mm, Nikon's default filter size from many years ago. As you know, filters are threaded at both the front and rear to facilitate stacking. The lens side has male threads, while the side facing the world has female. The filter's optical glass disk is usually held in place with a narrow, threaded retaining ring can be unscrewed using a lens spanner wrench like the one pictured here*. By spreading or compressing the two spanner blades, you can adjust the width to accommodate almost any filter size. I found this spanner on Amazon, but many REAL camera stores may have these spanners available for sale, but be sure to call first. In a pinch, you can clamp two thin screwdrivers in the jaws of a bench vice, but these spanners are not that expensive, and useful for other projects.

Now for the filters. While you're at the camera store, ask to see if they have any old colored filters for black and white photography, with yellow, red, and green the most common. They can be difficult to sell because so few people use black and white film, and for most photographers, the effects can be simulated by using a monochrome preset in a digital camera. Very often these filters are just thrown in a drawer, and some dealers may just give them away. Don't worry if they are scratched since you will discard the glass anyway. Just be sure that the filters you choose do not have dented rings which can impede the removal of the retaining ring. 

I would up digging through a tub of discarded filters and lens hoods at a local camera store and found a like-new Hoya filter which I paid $5.00 (ouch!) for. Oh well, it's still cheaper than the worst new filter on eBay.

Once you've found a suitable filter, adjust your spanner to engage the two tiny slots located on the retaining ring. Look carefully, as they are very narrow. Use a piece of discarded rubber glove to hold the filter ring in the palm of your hand. Now engage the retaining ring slots with the spanner and carefully, but firmly, unscrew the inner retaining ring. After several turns you will now have an adapter with both male and female threads which you can screw  permanently into your plastic filter holder. The brass/aluminum filter ring you've just installed will certainly outlast the softer plastic threads.

Here's the actual video. If you can cut to the chase, advance to 1:28. 

*  I've also seen manufacturers use thin wire snap rings, perhaps as a cost saving gesture, or possibly to prevent warping of the glass.

Post Script: My order for the adapters was made on May 8, 2025 and delivered on May 20. Twelve days from the Czech Republic. Oh, a signature was requied upon receipt.