How do you avoid color casts in mixed lighting situations?

To balance light sources of different temperatures, such as daylight and tungsten, can add gels to the lights. Some photographers and DPs (Director of Photography - video) consciously choose to keep multiple light temperatures. This is called "Salt n Pepper". There's a way to work with light to make it feel natural and inviting. Sometimes variation, balance, and harmony is what makes something look beautiful.

It's called a white point. Use a color checker card in a test shot. The card has a gray scale/ramp. You map the neutrals from the ramp to your file. In your photo editing program, assign the white point to the whitest white on the card, with a curves adjustment layer, and your image will be color balanced. Then you can balance the shadows the same way, if you like. Learn how to read a histogram and learn how to use a curve. That's where you will set the the white point. You should work in RGB but apply the white point with a CMYK Measurement. White Point = C-2 M-1, Y-1, No black in the white point. Adjust the gamma. Done.

Colour temperature is perhaps the most important technical element in any photographic image. When it’s correct it goes unnoticed but when it’s wrong it will most likely ruin the viewer’s experience of that image. With colour temperature being such a subtle and sometimes maddening thing to get right the starting point of any colour grading exercise has to lie within setting up a colour balanced workspace which can be done with a calibration device. Once you have confidence that what you see on your monitor is an accurate description of the colour and tone held within that image you can start to make changes. I start my colour journey within capture one and then do fine tuning in photoshop where you can layer mask if needed.

Use auto white balance or a custom white balance. If that fails, or you prefer to take an easy approach, bounce a flash of the ceiling and override other light sources.

If the subject is close, the best way is to use the custom white balance of the camera on the subject. If it's a wide view maybe the preferential white balance is a good choice.

Middle grey (18%) is called middle grey because on a logarithmic scale its truely middle while lineair speaking its 18%. Now you know.

It's known as a white point. Utilize a variety checker card in a test shot. The card has a dark scale/slope. You map the neutrals from the incline to your document. In your photograph altering program, dole out the white highlight the whitest white on the card, with a bends change layer, and your picture will be variety adjusted. Then, at that point, you can adjust the shadows the same way, assuming you like. Figure out how to peruse a histogram and figure out how to utilize a bend. That is where you will set the white point. You ought to work in RGB however apply the white point with a CMYK Estimation.

Keeping also in mind, the power output of your flash dictates the temp. Lower power often gives a difference in kelvin. Make sure to shoot your colour checkers whenever dropping power a few stops.

For me, it’s a simple Physics that’s at play here. When the physics is not in harmony, that’s when the images look ‘not quite right’ or ‘having a cast’. Physics rule being that the shadow will always be the opposite colour of the colour of the light source. There’s always a tint to the whites or blacks, and I can get creative having had this physics in mind, I can push the limits or stay within to create unique but harmonious colour palate.

Using a meter is only half the story. I have never bothered to use one. You just need color correction gels and then you can check if it looks good on your camera. Using a grey card to balance the color in post is much simpler.

In my experience using flash or a reflector is the quick and easy way to counter mixed lighting issues in a scene. This doesn't always give the desired result. I recommend gels on lights or the flash to help balance the lighting.

Using gels can also help to correct the colour balance. With cto gels for both off camera small flash of gels for larger monolights you can correct skin tones, or match the kelvin value of your subject to the environment.

When using different reflectors, it's important to consider the covers or shades they come with. These can help you fill in any shadows that may appear cooler in tone, and create a warmer or cooler effect depending on your desired outcome for the image.

In the days of film, we had to use all of the above-mentioned techniques of bringing color gels and reflectors and extra strobes to a job. They still have a place in photography, of course, but most of the work of color correcting can be done in editing software like Photoshop, with a higher degree of accuracy. In real estate photography, I use a tripod to capture bracketed exposures of the same scene, and then combine them into one HDR photo. There are typically indoor and outdoor light sources, and I can mask and balance color balance areas of the image in Photoshop if needed. Bringing gels and lights and color meters to a job would add hours to what only takes minutes in editing software.

In my experience most photographers nowadays prefer using editing software's to correct colors in mixed lighting situations if it's not possible to control the environment. This can be much faster and cost effective as well. With AI editing tools developing at a rapid rate this method will get even more accurate and quicker.

A strong understanding of color theory will help to balance out the colors in post, but take note; certain highlights and shadows might not be the outcome intended. The best way is to make sure your Color temperature is set according to something close to the final result intended, to prevent such headaches.

I've found that using color grading can be a much more effective way to control the color cast of the shadows, highlights, and midtones without correcting the whole image. It allows for more targeted adjustments and helps to maintain the overall balance of the photo. Have you tried this technique before?

In mixed lighting, you can’t avoid colour casts, maybe adding flash will help but that will also fill in the shadows. You can make a white room look like a gentlemen’s toilet doing that, which is somewhere most would not wish to live. The yellows from tungsten table lamps and other single sources of light can easily be remedied in Photoshop using the Image/Adjustments/Replace Colour tool. It’s quick and dirty and easily adjusted.

Use Flat field 18% gray chart for LSC calibration in ISP. Color cast generally comes when light hit sensor from side, which means most of the time colour cast occurs at side and corner area of an image. Lens shading and colour cast can be fixed by calibration and getting look up table which will be applied every time. Calibration needs to be done for different CCT and lux, To make sure it works well in different light condition like outdoor, indoor, low light and different colour temperature range from 2000K to 10,000K. Some ISP required calibration just for one CCT only. The whole process requires a light controlled camera lab, calibration algorithm and camera device. If shading exists after calibration, it needs to fine tune with AWB

Colour is deeply subjective. When shooting make sure to shoot for your destination. Meaning. Shoot a sRGB workflow for digital delivery and set your monitor accordingly. Same for print. Shoot AdobeRGB and set your workspace to P3 or AdobeRGB and make sure to lower brightness for accuracy in prints.

Gels are the key if you are using your own lights to even out the temperature of them with ambient light, and if it's just too bad and you can do nothing about it (old catholic churches with weird yellow chandelier lights and blueish light coming from the high windows and doors... and you're not allowed to add your own light spring to mind immediately) - your best bet is to switch to black and white images, as it is just irreparable in the post and you have no way to correct it on site.

Shoot in RAW for photography and shoot is some form of RAW or Log in video, this also gives you more power in post, when it comes to color grading.