How to Color Match Your Lights & More – Sekonic C-800 Spectromaster Review

by Scott LeslieJune 27^th, 2019

The LED revolution has come to the lighting industry – and its here to stay  – but it has brought its own challenges.  These days, with the proliferation of different brands and especially with RGBW lights, nailing your color amongst these different instruments can be onerous. Now, with the Sekonic C-800 Spectromaster Color Meter you can not only evaluate the quality of light emanating from different lighting sources, you can also measure your different lights to quickly see their offsets and determine how to correct them.  While this review focuses on LED lighting, the C-800 can measure any light source from HMI, tungsten, fluorescents, electric flash, natural light, and practicals.

One thing that the Sekonic C-800 is not:  it’s not an exposure meter.  It does not tell you f-stops, shutter speed or ISO for your camera; instead, it’s designed for ultra-precise color measuring.

Color Quality

The Sekonic C-800 gives you several different measurement standards to evaluate a light’s color quality and accuracy. The meter measures the CRI, TLCI and the newer SSI and TM-30-15 of light sources. While CRI (Color Rendering Index) has been the default standard that manufactures have used to evaluate their lights, there are now more critical and accurate standards being adopted. I am by no means an expert on this subject, but from what I have learned, the CRI (Ra) compares nine color patches to a standard light source (extended CRI compares 15 color patches). One issue is that the CRI gives a score for color rendition as it appears to the naked eye, where camera’s imaging sensors can perceive light very differently. This is where TLCI (Television Lighting Consistency Index) comes in. Instead of using the naked eye as a base, TLCI calculates the color response that would result when using a three-chip video camera. It uses the 15 color samples from the Macbeth chart.
Now The Academy of Motion Picture Arts and Sciences has come up with their own color index call SSI (Spectral Similarity Index), which is reportedly better for solid states lights such as LEDs. It is also more geared towards the spectral sensitivities of single-chip cinema or still camera digital sensors.
Finally the new TM-30-15 (Technical Memorandum) bases it’s calculations on 99 samples instead of 9 or 15 sample of CRI or TLCI and it evaluates a light source not only on its closeness to a reference light source, but also on its increase or decrease in chroma (saturation).
Whatever standard you want to use, the Sekonic C-800 has you covered. You can reference any and all of these measurements from the same meter.

Multi Light

The multi light function on the Sekonic C-800 allows you to measure up to 4 lights and, by setting one of the lights as your base light, you can see the offset of each light. This can be really handy to first see how off your lights are – and once you correct them, you can double-check your correction by retesting in this multi light mode.

Matching CCT (Dual Color) Lights

Here a scenario I have faced: While lighting a white cyc or white seamless there is a visible color shift on the white because the lights are not matched.  With the Sekonic C-800 there are two different ways to match your lights.

1. Through the filter mode, you can set a target color temperature (i.e. 5600K) and the C-800 tells you the exact Lee or Rosco filters needed to achieve that target. You will need to put the correct filter per each light.
2. If you’re working with dual color lights that also have green plus/minus adjustment, then it’s much easier. By setting one of your lights to be the base light, you can dial in the Kelvin and green/magenta of your other lights to match the base light.  No filters needed!   This is a little hard to explain but it is really clear on the video, so take a look.

Matching Colored Lights

With the explosion of RGBW lights on the market at more affordable price point, these lights are becoming much more common on set.  As a DP, I was really interested in exploring the color matching features of the Sekonic C-800.  Through using either the Hue and Saturation or CIE 1931 (x,y coordinates) you can confidently match your colored lights.

As a test, I used a daylight balanced 2K with a green gel and matched an Arri Skypanel S60-C, Lupo Superpanel Full Color 60 and a Superpanel Full Color 30 to the 2K.  With the Skypanel’s new firmware update there is a CIE 1931 mode where you can easily dial in x and y coordinates.  Using the Sekonic C-800 you simply take a measurement of the light you want to emulate and note the x, y coordinates.  Then you dial those numbers into the Arri.  Done.

The Lupo Superpanel Full Color 60 & 30 don’t have a CIE 1931 (x,y) mode, so for these lights you can use Hue & Saturation measurements to dial in the color. While holding the C-800 in front of the light, dial the light’s hue and saturation knobs until they match your target. This works just as well but takes a little more time.

Conclusion

In today’s lighting world, you can find yourself thrown into many different lighting scenarios with an ever-growing diversity of lighting instruments. Through using the Sekonic C-800 Spectromaster Color meter, you can be confident in the quality of light and color that your lights are producing.  With a price tag just under $1,600, this meter is an investment.  So if you’re just starting out, this probably is not for you but if you’re a working professional it is a great tool to have in your lighting toolkit.