Have you ever heard of kelvin temperature? Did you know it was based on a scale? Did you think it was instead of celsius (yes that’s an actual question from google). Well, kelvin temperature is actually the scientific study of the temperature of light. Yes, light truly has a temperature and even if you think you haven’t noticed it…you have. Kelvin temperature is based on a scale from about 1000K to 10000K. 1000 being warmer than candlelight and 10000 being cooler than blue sky. So what does this have to do with photography? Quite a bit actually. Using the kelvin temperature scale helps you to determine how warm or cool your overall image is. It makes a huge difference for your photography in general. But remember that color is very subjective to the artist and to the viewer. Below I will list the common temperatures to use for indoor photography, outdoors photography, and more.
Camera White Balance
Kelvin temperature is thought of, essentially, as white balance. On your camera it is often set to Auto WB, which is totally fine, but there are several options under white balance that you can pre-select on your digital camera. And when you choose one of those options you are selecting a corresponding kelvin temperature—the major ones listed below:
- Incandescent: 3500K
- Fluorescent: 4500K
- Direct sunlight: 5500K
- Flash: 5500K
- Cloudy: 6500K
- Shade: 7000K
So when you decide to stop using auto WB and explore the options under “kelvin” or “preset manual” then you can control the color in the scene. For example, if you are outdoor during a shoot and choose daylight mode (or set your own kelvin temperature to 5500K) you will have even color temps for the entire shoot and do not need to so much fixing in post production. Or even if it does change, it won’t jump from photo to photo so much. Instead you’d be able to change a swatch of photos and match them perfectly.
Outdoor Photography White Balance
There isn’t always a perfect place to start in using a kelvin temperature scale, but it is important to note that daylight on a sunny day is usually referred to as 5500K temperature. As an outdoor photographer, I tend to use this as my starting point and dial it up or down from there. The great part about kelvin temperature is that if you choose to set your own starting point, you do not need to do as much work during the editing process. Because you set it directly on your camera this will keep your image tones even for the entire session.
So outdoor starts at 5500K but as you get closer to the evening the light temperature may start to warm up, I talk about this more in this blog post about golden hour. Because of the warming of light you may need to dial your kelvin temperature down to compensate for the warmer light. Otherwise everything will start to look orange. Alternatively, if you’re photographing in the shade or under a tree the light is cooler so you tend to need to bring up the kelvin temperature to warm up the photo. That is why shade and cloudy days have a higher kelvin temperature than a bright sunny day. Is this making sense?
Indoor Photography Color Temperature
Indoor photography with incandescent lights (regular house lamps) starts around 3000 kelvin. This means the light tends to look a whole lot warmer (and cozier) but if you are trying to get more natural looking color from an indoor session, then you will need to dial that kelvin temperature down from any outdoor shots you just did. Again, 3000K is just a starting point and you may want your photographs a bit warmer or cooler because as I mentioned above, color temperature really is quite subjective.
Indoor shoot with daylight and overhead lights (like the one I show right here) is pretty tricky. You need cooler temps to compensate for the overheads but not lose the natural warmth of the daylight coming through the windows. In a case like this, try something in between 3200-5500K. In this photo you see windows, sunlight, and likely LED lights from the chandelier…very tricky. In this case, 4200K gave me the right color and I did a bit of warming on the subject in post-production.
When you used to purchase film, they had outdoor and indoor film. Outdoor film was always set to 5500k and indoor film was always set to 3200K. If you wanted to change the color—even a little bit—you needed to add color filters to your camera lenses. Oh those were the days! And don’t even ask me about shooting in a space with fluorescent bulbs above…your photos would turn green unless you added a crazy pink filter. Yuck!
Using Flash With Kelvin Temperature
If you’re an event photographer or a wedding photographer you may come across the need to photograph inside using flash. So what is the correct kelvin temperature setting for flash? Well, this one gets tricky again. Flash is generally balanced for 5500K, but the room you’re in is likely warm with incandescent light (3200K). So do you split the difference? Maybe. Mostly this is dependent on several factors—how strong is your flash versus how much background lighting are you bringing in? How bright is the room? Are the lights turned off? These all play a part in color temperature with flash. For example, I photograph by dragging my shutter and using rear curtain sync (that’s for another post all together) and so my kelvin temperature is generally set lower to match my room lighting because I am relying less on the flash itself and using it more as a fill flash than as a main light source.
In this image seen here, my kelvin temperature was 4800K but I was working with many different light sources. The warmth from the chandeliers, the cooler temp of the flash, and the cooler temp of the actual colored uplighting. Thankfully, after the kelvin temp is set in camera you will still have options for tint in post-production and that helps even out color overall.
Where to start With A Kelvin Temperature Scale
So where to start? Start with your main (and major) light source. Dial in that kelvin temperature and see how it looks on the back of the camera. The beauty of digital photography is definitely it’s immediacy and the fact that you can make changes on the fly. Once you start using kelvin temperature as your white balance setting you will be very fast at changing the settings for all lighting conditions and you’ll start to get used to your own personal kelvin settings (mine tend to be strange number like 6250K or 4780K). I use them regularly as starting points and find I need to do little changes for a short one-hour session. Give it a try during your off season and start to get used to your own personal favorites!