[Zafar Iqbal]

How would you go about to identify the color temperatures on various light sources, while being on a gig? For instance, Flash (I know that one) LED light, flourecent tube lighting and bulbs and mixed in with a good amount of natural light.

"Problem" is, I'm having hard time telling them apart while I'm out shooting wheres the colors become clearer when processing.

[tuco]

With a Color Temperature Meter of course.

[vonBaloney]

When I was shooting a lot of film and doing cinematography (with film), I got so I could see the temperature with my eyes -- with digital white balance, not so much. Need a meter. Of course you can use your camera to take test shots, white or grey card readings, play with the custom WB to see where it is, etc. (There are apps for your phone as well, but of course a real color meter will be the best and easiest.)

[Zafar Iqbal]

Do all/most advanced light meters also do this? I've never heard of Color Temperature meters

[stevebrot]

With a Color Temperature Meter of course.

For inquiring minds, I am sure!

Seriously though, I suspect that a meter like that would be a huge boon to colorists on set for motion picture production in that it provides much better control than is available in PP. For the rest of us, it probably would not be worth the cost unless the we also had the means to tailor the temperature of the various light sources and the knowledge of what the intended target should be.


Steve

---------- Post added 10-07-14 at 10:12 AM ----------

Do all/most advanced light meters also do this?

No, the meter in the link above and its companion model (w/wireless!) are unique and pretty cool. I suspect that these meters use technology similar to the RGB meter sensors in the K-3 and D7100, both of which assist the auto color temp for the camera.


Steve

[vonBaloney]

If you are only interested in setting white balance, then just get an expodisc (or one of the cheap alternative "white balance cap"s) and learn how to use that to set your WB...

[jatrax]

If the light is consistent you can use a gray card or expodisk to set the WB. If light is mixed then you are in a tough situation.

As to actually identifying the temperature from light source used, that used to be possible when most lights were incandescent. These days it is nearly impossible without looking at the bulb and hoping it has a temperature value on it. Tungsten bulbs used to be 2700 - 3000K but they are now available up 5500K. Fluorescent can vary widely and also have color casts that are hard to deal with. LED can be just about anything. Many places are transitioning to new bulb technology so I am finding mixed light sources more common. A mix of old tungsten, CFL and LED is a nightmare.

[Na Horuk]

With a Color Temperature Meter of course.

And it only costs $1,216.00! Not much more than the K-3+grip

Regarding temperature.. LED lights are really terrible, because they have highly saturated colour channels, but a very narrow colour spectrum. The other problem you mention is mixed light sources. Both of these are big problems with modern lights, because there are so many types of bulbs, with different characteristics and colour temperatures.
I often just switch to black and white, so I just have to watch composition, focus, and so making sure the photo is not too bright/dark. The other thing you can do in post processing is Split Toning to add a uniform colour cast over the highlights. These are just PP tricks, though. I don't have an answer on what to do beforehand

[tuco]

And it only costs $1,216.00! Not much more than the K-3+grip

Regarding temperature.. LED lights are really terrible, because they have highly saturated colour channels, but a very narrow colour spectrum.

You have to pay to play

I'll take white LED lights over those terrible orange street lights any day. Those things are terrible. The white of many LED lights is more manageable it seems. And example of mixed white LED and other sources on a recent shot.

[wombat2go]

Slightly off topic, but in the steel industry, the skilled operators can eyeball the temperature of their red hot (~950 K) and white hot ( ~ 1500 K) steel within about 10 K.

[tuco]

Slightly off topic, but in the steel industry, the skilled operators can eyeball the temperature of their red hot (~950 K) and white hot ( ~ 1500 K) steel within about 10 K.

That is thermal temperature not color temperature they are estimating.

[jatrax]

I'll take white LED lights over those terrible orange street lights any day.

Sodium Vapor HID bulbs. Just about the worst light ever invented. Supposedly the bulbs are cheaper and run cheaper as well. We used to have them in our parking lot.

LED seems to be the coming technology so I think we are going to have to learn to understand it. I think it will get better as we move forward. I've not had too much trouble with the white as long things were not mixed up too much but the solid color ones used for accent lighting are hard to deal with. They just blow out the color channel.

[Zafar Iqbal]

No, the meter in the link above and its companion model (w/wireless!) are unique and pretty cool. I suspect that these meters use technology similar to the RGB meter sensors in the K-3 and D7100, both of which assist the auto color temp for the camera.

Alright - I dig around quiet a bit, so it surprises me I haven't heard of a color temperature meter before.

If you are only interested in setting white balance, then just get an expodisc (or one of the cheap alternative "white balance cap"s) and learn how to use that to set your WB...

If the light is consistent you can use a gray card or expodisk to set the WB. If light is mixed then you are in a tough situation.

As to actually identifying the temperature from light source used, that used to be possible when most lights were incandescent. These days it is nearly impossible without looking at the bulb and hoping it has a temperature value on it. Tungsten bulbs used to be 2700 - 3000K but they are now available up 5500K. Fluorescent can vary widely and also have color casts that are hard to deal with. LED can be just about anything. Many places are transitioning to new bulb technology so I am finding mixed light sources more common. A mix of old tungsten, CFL and LED is a nightmare.

What bothers me the most are lightsources with green tint in them - I often either can't identify them, or identify them late.

I'm currently working on a bunch of photos where the WB is fine in the beginning - but half an hour later, with slightly lower sun and some light turned off and possible some others turned on (I didn't noticed additional lights being turned on, only that some were turned off), the WB is all over the place and to a degree that surprised me. Greenish here, blue there, orange other places.

The green tint bugs me the most and that's what I'm mostly interested in neutralizing - but when I can't see it, it means I'm not using the proper gel on the flash.

And it only costs $1,216.00! Not much more than the K-3+grip

Regarding temperature.. LED lights are really terrible, because they have highly saturated colour channels, but a very narrow colour spectrum. The other problem you mention is mixed light sources. Both of these are big problems with modern lights, because there are so many types of bulbs, with different characteristics and colour temperatures.
I often just switch to black and white, so I just have to watch composition, focus, and so making sure the photo is not too bright/dark. The other thing you can do in post processing is Split Toning to add a uniform colour cast over the highlights. These are just PP tricks, though. I don't have an answer on what to do beforehand

Many wedding venues here use colored LED's and I always ask for these to be turned off for other that obvious reasons, such as proper partying.

The mixed WB's is a complete mess and I'm seeing this many many places. On the fancier places, however, the WB is generally much more even.



---------- Post added 07-10-14 at 19:44 ----------

You have to pay to play

I'll take white LED lights over those terrible orange street lights any day.

I really really dislike those as well. Nice light and wonderful WB going on in the pic.

[dms]

Thermal temperature and color temperature are the same for continuous light spectrum--e.g., incandescent/tungsten lights

For above the older color meters work fine, and a used Gossen sixticolor meter (which I used) can be had for likely $50.

But for mixed lighting it (an older inexpensive color meter--not sure about the more recent costly ones) is of questionable value, and more over for digital it is not very useful--as the color balance is best set in raw by finding a gray or white area in the image (even the white of the human eye works pretty well--if nothing else is present) . But whether you want to balance the scene for the way it would (should?) look if lit by sunlight is another matter.

[jatrax]

What bothers me the most are lightsources with green tint in them - I often either can't identify them, or identify them late. I'm currently working on a bunch of photos where the WB is fine in the beginning - but half an hour later, with slightly lower sun and some light turned off and possible some others turned on (I didn't noticed additional lights being turned on, only that some were turned off), the WB is all over the place and to a degree that surprised me. Greenish here, blue there, orange other places.

Maybe fluorescent? They have a greenish cast sometimes but every manufacturer has a slightly different formula. Over time what seems to happen is bulbs are replaced by maintenance staff and they just buy the cheapest they can find. So even though the original installation might have had good quality color balanced bulbs you end up with a crazy mix of brands, color temps and even bulb age that will all have an effect. When you are getting some sun that tends to add enough natural light to mask the bad light but as the sun goes down the artificial light predominates and you get all kinds of weird things.