Help with temperature of light please

[Joan Breckwoldt]

Hello everyone,

I have been struggling to get good resource photos and I have come a long way, but . . . .

I recently posted my 'babysitter photos' and I was using a light that I thought was imitating naturaly daylight, which would be cool since there is blue sky which makes the daylight blue. I will post one below. After reading just about every single post on this forum about lighting a model, I used a flourescent spiral lightbulb, 75W. I understood this light was close to 5000K temperature. Chris Saper was very very helpful with this information, thank you Chris.

But from looking at my babysitter photos it looks like this gave me a warm light? The bottom of her body is illuminated by the natural light and it's a cool light. So I have half cool and half warm light on my model. Not my intention. I am trying to get a cool light everywhere.

So, I'm confused, I was expecting to get a nice cool light. I like the intensity of this light and I am happy with the shadows it gives me, etc. I feel like I have made a lot of progress with the help of this forum getting light on my model! But, wrong temperature. I just don't understand why this light is giving me such warm photos!

Any help here would be appreciated. Thank you,

Joan

[Julie Deane]

As I recall, according to Chris Saper's skintone book, 5000K is a warm light, closer to what you would get in the late afternoon. You would need something like 6500K for a cooler light.

Both are daylight - but what time of day is what the numbers help to tell you after you get to know their meanings.

[Joan Breckwoldt]

Julie,

Thank you for bringing this to my attention. I have Chris Saper's book and after looking up some info on my lightbulb, I was mistaken, the bulb I used for my 'babysitter portrait' photos including the one above was a 6500K bulb, just as you thought it should be.

So I still have the same question, why does this 6500K bulb give me a warm photo?

Joan

[Julie Deane]

Hi Joan -

I sure don't know. All I can suggest is to try other lighting. Look for Marvin Mattelson's reviews of some of the lights he is using - from his description they sound like they might give better results.

[Vincent Shaw-Morton]

Hi Joan,

I think the main problem you have with this photograph is the mixing of two different light sources that have two different colour temperatures. It may have not been noticeable with the naked eye at the time, but as you point out is easy to see in the photograph.

Also the top part of the picture is a lower value than the bottom half, again due to a low power, warmer light. This has made your subject look as though her face is in shadow, pulling attention away from her face and onto her bust and hands.

The lower half of the photograph looks correctly exposed, the colour balance on the hands l good.

Using two light sources can work well, I took a reference picture of someone lit from a north facing window and hadn't noticed that my studio door was slightly open. The hall light was on and when I looked at the picture (digital) saw that even though the front of the model was well light with cool daylight, there was a low value subdued warm light on the back of the head and ear. I didn't notice it at the time and this lucky accident worked well.

Try taking the picture again but ensure that you only have one light source, either daylight, or artificial light, however not only avoid mixing daylight and artificial light, but also different types of artificial lights such as fluorescent (which can have a greenish colour cast) and tungsten (warmer and red).
I hope this is useful.
Best Wishes
Vincent

[Vincent Shaw-Morton]

Oops,
something I meant to add in my last post was that the reason the cool artificial light looks warm is because of the very cool temperature of the natural light next to it If you take a photograph using your cool artificial light AND an ordinary warm tungsten light together then in that photograph your cool fluorescent spiral light will look cool compared to the tungsten. Its all comparative.
Vincent