I’ve finally got my hands on that thing I’ve been wanting for a while.
It’s a Color Balance Lens, also known as a CBL lens.
This is a tool for adjusting the white balance to the correct setting without color cast. It is a kind of luxury version of the “gray card” that is often used when manually setting the white balance on a camera.
When I took part in a beginner’s class hosted by PENTAX a few years ago, the instructor introduced and showed me the CBL lens, saying “If you want to take vivid photos of autumn leaves under cloudy skies, you’ll have to adjust the white balance, which can be difficult, but this will solve the problem in one go”, and it made a strong impression on me, and I’ve been curious about it ever since.
Recently, I’ve seen some people saying that the auto white balance function built into cameras has become so accurate that there’s no need for gear like this anymore. However, I’m terrible at everything, and I’m particularly bad at adjusting color tones, so I’ll grab anything that can help me, whether it’s a straw or a CBL lens. Fortunately, the price has gradually become more affordable, so I decided to get one before the autumn leaves season.
I tried it out straight away.
I wanted to see how the color of the flower boxes placed by the roadside would change depending on the white balance setting on a dull, overcast day. The camera equipment used was a LUMIX S5 and SIGMA 50mm F2 DG DN, and the color temperature and hue values are reference values read by PhotoLab7.
WB setting: AWB (Color Temperature 7085 HUE 6/PhotoLab7)
WB setting: Cloudy (Color Temperature 5704 HUE 8/PhotoLab7)
WB setting: Manual CBL lens (Color Temperature 6785, HUE 9/PhotoLab7)
I was having trouble finding information on how to use CBL lens on minor LUMIX models, either in the manual that came with the camera or on the website, but I think I’ve figured it out by trial and error (I hope so).
The order of color temperature was AWB → CBL lens manual → Cloudy sky. The colors that are easy to compare are the colors of the white and red flowers, the green of the leaves, and the dirty white of the box wall, etc. “Cloudy sky” has less redness than the others, so the whiteness of the white flowers stands out, but the other two are closer to how they look to the naked eye.
I think the color reproduction of the flowers and leaves in the “CBL Lens Manual” setting is particularly impressive.
The “AWB” setting is also very good. There is a slight difference in color temperature between the “CBL Lens Manual” and “AWB” settings, but I don’t really notice a difference in color between the two settings, perhaps because the “CBL Lens Manual” setting HUE is slightly more magenta. This may be an example of how good the camera’s auto white balance is.
I don’t understand the optical mechanism at all, but anyway, using the CBL lens, I was able to set a white balance that differed from the camera settings, and I was able to confirm that it would be effective in terms of reproducing the colors of reality (at the same time, I also realized that the camera’s AWB is quite good).
Now, I’m looking forward to seeing how much use I can get out of it, but I’m also a little worried.
