Soap Bubble Wiki

Evaluating Color[]

Color provides valuable information about a soap film. The lighting environment is the key to getting a clear read of a bubble's colors.

These bubbles made simultaneously with identical equipment display dramatically different color profiles. The profiles tell us that the bubble juice used for the lefthand bubble creates much thinner films than the solution used for the righthand bubble.

The colors are clear here because there is diffuse indirect light -- thanks to thick cloud cover early in the morning -- and a relatively dark background. In direct sun and/or with a light background, the colors would be faint. [This recipe using a 20:1 Water-to-Dawn ratio and a 100" top-string tri-string loop]


A bubble's colors tell you a lot about the soap film. Getting a good read on a bubble's colors is critical for serious bubbleheads and mixologists. In order to see the colors, however, you need appropriate lighting conditions.

Why are your bubbles so colorful? Many people want to know what are the ingredients that make the bubble colors so bright. But, it isn't anything special about the bubble juice: it's the lighting environment. I am lucky to have a dark background across the street from my house, and most of my giant bubble pictures are taken on heavily overcast days.

Two elements are critical for getting a clear look at a soap films colors:

  • diffuse white light
  • a dark background

Background. Against a dark background, the bubble colors will seem bright and saturated due to contrast with the background. Against a light-colored background, the colors are difficult to see clearly.

A simple setup for capturing bubble colors well.

Diffuse light. For diffuse light outdoors, a heavily overcast day is beneficial. The outdoor bubble pictures on this site that have the most saturated colors were taken on days when the sky was heavily overcast. For indoor pictures here, the light source was either bounced off something (such as a white wall) to diffuse it or was filtered through something that acted as a diffuser. In the summer of 2017, I came up with a simple setup involving a strong shoplight (as we call the in the U.S.), plastic painter's dropcloth, a pvc pipe frame and a black cardboard background. It was used to take the picture at the top of this page. You can read about it here: User_blog:Espiegel123/Lighting_Setup_Sept_2017.

Lighting Conditions Influence The Ability to See the Colors[]

Below are two pairs of bubbles made using the same bubble juice. In one photo of each pair, the color profile is easy to see, but in the other photo the profile is almost impossible to see due to the conditions.

The first pair of photos use the same juice but were taken at different locations at different times of day. The first photo was taken early in the morning with a very cloudy sky. Only diffuse indirect light was present, and the background is dark.

With the right conditions, the bubble colors can be seen clearly. Juice: eGoo/HEC hybrid with excellent lighting conditions. Approx dilution: 24:1 (water:detergent) The colors of this bubble can't be evaluated properly due to the lighting conditions. Juice: eGoo/HEC hybrid.

The photos below were taken just moments apart from different vantage points. In bubble 1, the color profile is easy to see. The photographer has moved and bubble 2 is taken against a light background that washes out the bubbles colors.

Bubble 1. Two bubbles made with the same bubble juice photographed moments apart from different angles. Dilution: approx 16:1 mix includes guar gum and other polymers. (Photo: T. Poersch). Click on photo to zoom.

Bubble 2. The same juice and sun angle taken from a different angle.



If you are a bubble juice brewer or mixologist, evaluating bubble colors is a critical task. I had been making bubbles for several years before learning the importance of color evaluation and the importance of the right environment for evaluating them. It was something that for some reason was not discussed by bubblers. Those early explorations would have been much more fruitful if I had understood that the bubble colors convey critical information about the bubble film: the colors are a map of the soap film's thickness. As discussed elsewhere (see Dilution and Color and Film Thickness), adjusting the soap film's thickness allows you to optimize the solution for the conditions and your equipment.

Bubble colors are not always easy to see well enough to evaluate them. So, it is important to find a place to make bubbles where the colors can be properly seen.

Odds and Ends[]

A great experiment that would greatly benefit us bubblers would be if someone were to set up many cameras at different heights and angles photographing (video would be best) the same bubble against the same nice background in order to illustrate how the angles cause a shift in colors.

Wayne Schmidt's Color Studies[]


Best Lighting for Soap Bubble Colors

Wayne Schmidt has explored many issues related to giant bubbles and created some videos that do a good job of illustrating the issues of bubble color evaluation and lighting.


How To Blow Giant Bubbles Part 3

Wayne constructed a black backdrop to improve the color evaluation even more. Find out more here


See Also[]

If you are trying to optimize your bubble juice, these related articles are critical to understanding the relationship between dilution, color, film thickness and related factors such as size potential and longevity.

Color and Film Thickness - soap film colors give very specific important information about the bubble thickness and is closely related to the soap concentration in a way that most people find counter-intuitive.

Dilution - Dilution/soap concentration has a critical impact on the bubble longevity, colors and size potential. If you are trying to optimize your bubble juice this is a critical topic.

Color Profile - article about the 'color profiles' that help evaluate the film thickness achieved with different dilutions

Dawn Pro Dilution Evaluation - This article illustrates Dawn Pro-based bubble juice at various dilutions. Use these examples to help you tune your juice and determine the equivalence between your detergent and Dawn Pro.

Photographing Bubbles - a stub page that has some worthwhile discussion nonetheless.