5500k vs 6500k

[DNAustrem]

Looking to invest in some new pro\am lighting kits so I'm curious on people's opinion regarding the differences between 5500k and 6500k softbox lighting.

It would mainly be used for interviews, YouTube vlogging and I do a fair bit of sports and glamour video/photography so it needs to capture healthy natural skin tones.

Would 5500k or 6500 lights be more appropriate?

If I ended up with buying 6500k lights would popping a red /orange fleet over the lights to help balance out the slightly bluer, cooler tint work?

 

[Klaus dk]

Choose the lights with the highest CRI. As long as you don't mix different colour temperatures, CT is insignificant since you can set it in manual WB.

 

[Michael Fryd]

Looking to invest in some new pro\am lighting kits so I'm curious on people's opinion regarding the differences between 5500k and 6500k softbox lighting.

It would mainly be used for interviews, YouTube vlogging and I do a fair bit of sports and glamour video/photography so it needs to capture healthy natural skin tones.

Would 5500k or 6500 lights be more appropriate?

If I ended up with buying 6500k lights would popping a red /orange fleet over the lights to help balance out the slightly bluer, cooler tint work?

If your lights will be supplementing existing lighting, then it is helpful to match the existing lighting.

For instance suppose you are shooting someone at the beach. They are in a shadow so you shine your lights in them. The background is lit by natural sunlight. If the color temp of your lights differs from natural sunlight, then you may see a color different between the subject and the background. With a proper white balance, the subject will look good, but anything in the background (lit by natural light) may be a bit off.

Similarly, if you are shooting someone indoors, you may want your lights to match the ambient lights.

They do make gels so you can fine tune the color temp of your lights, and they make lights with variable color temps.

Depending on your needs and light style, none of this may be significant. If you properly light a pretty girl in a skimpy swimsuit, no one may notice that the background colors are slightly off.

As others have mention, the CRI of the lights are probably more important than the color temp. I would rather have high CRI lights that were slightly off on color temp, then to have low CRI lights at the matching color temp. Ideally I would like both high CRI and matching color temp.

 

[hotdog321]

Looking to invest in some new pro\am lighting kits so I'm curious on people's opinion regarding the differences between 5500k and 6500k softbox lighting.

It would mainly be used for interviews, YouTube vlogging and I do a fair bit of sports and glamour video/photography so it needs to capture healthy natural skin tones.

Would 5500k or 6500 lights be more appropriate?

If I ended up with buying 6500k lights would popping a red /orange fleet over the lights to help balance out the slightly bluer, cooler tint work?

Yes, it is common practice to gel lights either to color correct or completely shift the color. In fact, you may find 5000 K to be nicer. That said, why bother? I would buy 5500 K;I don't see an upside in buying the 6500 K lights.

--
photojournalist
http://craighartley.zenfolio.com/

 

[Xasan]

To nitpick, most of the current sensors are optimized somewhere between 4000 K and 5000 K to improve performance under a wider range of lighting conditions. That being said, the difference between 6500 and 5500 or even 6500 and 5000 is not a deal-breaker.

First concerns should be: the smoothness of the spectral power distribution of the light source as well as how close it is to blackbody radiator.

If you are looking at LEDs, lower CT sources often have better smoothness.

CRI is not a good quality indicator for LEDs and FL lights. Yoshihiro Ohno (A.K.A. Yoshi Ohno, works for NIST) presents why in https://energy.gov/sites/prod/files/2016/02/f29/ohno_human_raleigh2016.pdf

Here is a benchmark for some of commercially available lights that is more useful then straightforward CRI:

The Guild of Television Camera Professionals : Current TLCI Results (archived) - GTC | The Guild of Television Camera Professionals

The Guild of Television Camera Professionals (GTC) is an independent, international organisation that cares about camerawork and the people who make it their craft.

www.gtc.org.uk

Qa replaces CRI, d indicates the deviation from blackbody locus, better to have d magnitude below 0.5

See http://www.gtc.org.uk/members-area/tlci-results.aspx for some background.

 

[Xasan]

Choose the lights with the highest CRI. As long as you don't mix different colour temperatures, CT is insignificant since you can set it in manual WB.

Small differences in CT, below 50 mired from 5000 K, are insignificant. Larger differences lead to significant amounts of exposure dis-balance between color channels and result in more noise.

 

[digidog]

Choose the lights with the highest CRI. As long as you don't mix different colour temperatures, CT is insignificant since you can set it in manual WB.

Actually CRI is a kludge and has nothing per se to do with a CCT Kelvin value which defines a pretty large range of possible colors**.

CRI, a bit of a hack to make a light source appear to be closer to daylight for marketing and light manufacturers. CRI was developed in large part to aid in the sales of Fluorescent tubes. There are tiles used to compare under a reference light source but only eight. That's too small a set of tiles. That make it easy to create a spectrum that will render the 8 tiles and doesn't tell us that the light source is full spectrum. It doesn't tell us how the other colors will render. My understanding is there are two reference sources; Tungsten for warm bulbs and D50 for cool ones. That means that a normal tungsten bulb and perfect daylight both have a CRI of 100! As such, a high CRI is a decent gauge of how well a light will preform in your home but not such a great indicator of how well it will work for photography and proofing. Both a Solux 48 and a "full spectrum" tube from home depot may have a CRI of 97. I can assure you the Home Depot bulb has a giant mercury spike and some spectral dead spots.

** http://digitaldog.net/files/22Thecolorofwhite.pdf

 

[Klaus dk]

Choose the lights with the highest CRI. As long as you don't mix different colour temperatures, CT is insignificant since you can set it in manual WB.

Small differences in CT, below 50 mired from 5000 K, are insignificant. Larger differences lead to significant amounts of exposure dis-balance between color channels and result in more noise.

To the OP: To understand which lighting kit to choose, follow the links in the posts of my two learned colleagues.

Then, choose the light source which is closest to a black body radiator (No racism implied!) and set the white balance on your camera to the same Kelvin CT as the nominal CT of the lights. It may be wrong and unscientific, but it might work none the less.

I find it hard to believe that a digital sensor should not be able to adjust to the the different light sources available in the white balance menu, at least within reasonable margins.

 

[Klaus dk]

Choose the lights with the highest CRI. As long as you don't mix different colour temperatures, CT is insignificant since you can set it in manual WB.

Actually CRI is a kludge and has nothing per se to do with a CCT Kelvin value which defines a pretty large range of possible colors**.

CRI, a bit of a hack to make a light source appear to be closer to daylight for marketing and light manufacturers. CRI was developed in large part to aid in the sales of Fluorescent tubes. There are tiles used to compare under a reference light source but only eight. That's too small a set of tiles. That make it easy to create a spectrum that will render the 8 tiles and doesn't tell us that the light source is full spectrum. It doesn't tell us how the other colors will render. My understanding is there are two reference sources; Tungsten for warm bulbs and D50 for cool ones. That means that a normal tungsten bulb and perfect daylight both have a CRI of 100! As such, a high CRI is a decent gauge of how well a light will preform in your home but not such a great indicator of how well it will work for photography and proofing. Both a Solux 48 and a "full spectrum" tube from home depot may have a CRI of 97. I can assure you the Home Depot bulb has a giant mercury spike and some spectral dead spots.

** http://digitaldog.net/files/22Thecolorofwhite.pdf

 

[digidog]

Choose the lights with the highest CRI. As long as you don't mix different colour temperatures, CT is insignificant since you can set it in manual WB.

Actually CRI is a kludge and has nothing per se to do with a CCT Kelvin value which defines a pretty large range of possible colors**.

CRI, a bit of a hack to make a light source appear to be closer to daylight for marketing and light manufacturers. CRI was developed in large part to aid in the sales of Fluorescent tubes. There are tiles used to compare under a reference light source but only eight. That's too small a set of tiles. That make it easy to create a spectrum that will render the 8 tiles and doesn't tell us that the light source is full spectrum. It doesn't tell us how the other colors will render. My understanding is there are two reference sources; Tungsten for warm bulbs and D50 for cool ones. That means that a normal tungsten bulb and perfect daylight both have a CRI of 100! As such, a high CRI is a decent gauge of how well a light will preform in your home but not such a great indicator of how well it will work for photography and proofing. Both a Solux 48 and a "full spectrum" tube from home depot may have a CRI of 97. I can assure you the Home Depot bulb has a giant mercury spike and some spectral dead spots.

** http://digitaldog.net/files/22Thecolorofwhite.pdf

--
Andrew Rodney
Author: Color Management for Photographers
The Digital Dog
http://www.digitaldog.net

I never claimed that CRI and CCT had anything to do with each other.

But the OP is asking about CCT!

Actually, I wrote that the (C)CT (which was the foundation for the OP's question) was insignificant, and that the CRI was more important.\

CRI is a kludge, I explained why.

I agree that CRI is not a good measure of the quality of the light, but AFAIK, no nother measure for how close a light source is to a black body radiator exists.

There are far better ways to evaluate the light quality from the actual spectral measurement of the spectrum which I've provided in the URL: http://digitaldog.net/files/15TheRightLightpart1.pdf

Daylight spectrum on the left: Good. Spiky spectrum of Fluorescent right: Bad!



Additionally, using software and actual measurement data as seen here:

BableColor

--
Andrew Rodney
Author: Color Management for Photographers
The Digital Dog
http://www.digitaldog.net

 

[Xasan]

I find it hard to believe that a digital sensor should not be able to adjust to the the different light sources available in the white balance menu, at least within reasonable margins.

I don't know what to say except that sensors do not adjust. Software performs white balancing adjustments.

Please let me try to explain some.

Sensors are good these days, and they can tolerate a lot of total and channel underexposure, but why force it if there is a choice! Shots are easier to process if they are taken within that range, 4000 K to 6500 K (that is within 50 mired range of 5000 K).

Another limitation when going seriously off this range is that most of the color profiles are calculated for daylight around 5500 K and are rapidly beginning to cause color deterioration past that 50 mired range.

Of course one can try to rely on profiles for incandescent light source supplied by Adobe and use studio halogen lights at 2800 to 3200 K, but then it means studio halogen lights literally, and no LED or FL lights.

For lights out of that 50 mired range a better option is not to use a stock profile but do a custom one.

 

[PenPix]

6500K is closer to the colour temperature in open shade, so it is appropriate if you are shooting under those conditions and need the lights to match.

Shooting indoors where I am more likely to experience lights that are "warm white" or incandescent, I am using C.T. Orange filters to lower the colour temps of my 5500k lights... both strobe and continuous.

Personally, I have never had the need for 6500K lights. Even outdoors in the shade, the warmer colour temp add warmth to the skin tones which give it that healthy glow.