K40, 3200, 3400 & daylight

[chas_ucla]

This may be a dumb question but since I rarely shoot color I thought more knowledgeable people out there would know...

If I am shooting K40 indoors and my key light is a 650 W 3400 light and I have one or two fill lights that are 250 W and 3200 plus possible daylight will there be a mess with light temps?

[lightfeat]

In a word, yes. The difference between 3200 and 3400 is negligable, but it's really best to either eliminate daylight, or else shoot only in daylight, as the difference is much more than we generally perceive.

If you really want to mix the sources up, the thing to do is buy a colour temperature meter and lots of filter gels for windows and light sources. This is very expensive.

I recommend the either/ or option.

Lucas

[becomedeath]

Forgive the ignorance.
Could someone tell me how that works exactly. I thought that tungsten was 3400 K and daylight was 3200 K, or was it the other way around? Or am I way off base here?

[Greg Crawford]

The difference from 3200 to 3400 k , although warmer is still very small.

Assuming you are going to fill with the warmer light source, it might have the look that you warmed up the overall lighting with a gel.
With people and food it's best to be a little warmer rather than on the cold side.

If you gel ad a 1/4 to 1/2 CTB neutralize your warmer source you will lose more light. And in Super 8 as you know, it's better to have more light than not enough.

[lightfeat]

I really would recommend eliminating the daylight, as it will most likely look very blue and cold.

You could put blue gels (I forget the numbers) on the tungstens and an 85 filter on the camera, but that's crazy, as you'll lose too much light by far (that's why no-one does it.)

If you must have daylight, you could put 85 orange gel over the windows - it will look wierd to the eye, but it should work - I'd actualy choose a much subtler orange filter (but I don't have a chart with me) as I think daylight should look a little bluer than tungsten, but not as different as it will look unfiltered.

Keep us posted as to what you decide.

Lucas

[monobath]

In response to becomedeath's question, the color temperature of direct noon sunlight is around 5000K to 5400K. An overcast sky might be 6500K to 7000K, cooler in appearance than noon sunlight. A 3400K photolamp, or 3200K tungsten lamp, appears much warmer than sunlight. A candle is very warm appearing, around 1500K.

The 'K' is degrees Kelvin, a measure of temperature where 0 degress Kelvin is equal to about -273 degrees Celcius, also called absolute zero.

It should be understood that what we commonly refer to as "warm" and "cool" color temperatures refers to the way that we relate to them visually. We think of reds and oranges as warm, and whites and blues as cool "in appearance", but blue is actually hotter in temperature than red. For example, you know that a red dwarf star is a very old dying and cooling star, whereas blue-white stars are thought to be much younger and hotter.

Here's a good reference:
Kelvin Scale

[Actor]

K40 is balanced for 3400K. For 3200K Kodak recommends an 82A filter, assuming you are worried about the 200K difference.

http://www.kodak.com/US/en/motion/pr...8.shtml#expose

[chas_ucla]

Thanks guys, for the good advice. I think the easiest thing would be to eliminate the daylight. This is for my wife's art school project...there was really only going to be one scene where sunlight might have interfered... a scene where a man is washing dishes and facing a window that looks out over a garden...but hey, that's what blinds are for, right? ;]
The Photography tips page with the Kelvin info was great...good stuff to bookmark.

Chas

[chas_ucla]

<BLOCKQUOTE><font size=2 face="Verdana, Helvetica, sans-serif">quote:</font><table border="0" width="90%" bgcolor="#333333" cellspacing="1" cellpadding="0"><tr><td width="100%"><table border="0" width="100%" cellspacing="0" cellpadding="2" bgcolor="#FF9900"><tr><td width="100%" bgcolor="#DDDDDD"><font size=2 face="Verdana, Helvetica, sans-serif">Originally posted by Actor:
K40 is balanced for 3400K. For 3200K Kodak recommends an 82A filter, assuming you are worried about the 200K difference.

http://www.kodak.com/US/en/motion/pr...8.shtml#expose</font></td></tr></table></td></tr></table></BLOCKQUOTE>

Yeah, we discovered that right before we were starting out filming. Since I was using a 3400k key light and only one 250W 3200k fill, I didn't think the difference would matter too much. Anyway, I'll get the test footage we shot back from Dwayne's tomorrow or Thursday and I'll let you guys know how it turned out.

[Nigel]

I would say that 200k is quite a bit. Not as much as 2000k but still enough to notice. That was my biggest beef with the new Ektachrome. With an 85A it is blue.

My bit of advice is to look at the window. Your eyes are wonderful at balancing light. However, if you are sitting in a room with a lamp on you can see what daylight looks like. Sometimes mixed light is good and will well. Other times it looks foul and like you are a fool for shooting the scene.

Good Luck
PS--Rosco make great gels for everything you could ever want to do legal or otherwise.