Motivation for a Soft Key Light For one man band film-makers soft light is an absolute essential. 99% of our subjects are people and soft light is the most flattering way to light or “key” people’s faces. What makes light soft has nothing to do with it’s intensity or output. It has everything to do with it’s apparent size.
The sun is a hard light. One reason we know that is because it casts shadows with defined edges. It is not flattering on faces because it casts potentially unwanted forehead, eyes and nose shadows. What makes it hard is its apparent size in relation to us. Though it is enormously large, it is so far away that it appears small. We can reach out our hand and block out it’s rays.
The sky is essentially a huge bounce light. The hard light of the sun bounces off of the atmosphere and creates our daylight colored sky. The quality of the light is even and soft. What makes it soft is it’s apparent size. We cannot reach out our hand and block it’s light from our faces. That's because the sky’s light is so large in surface area that it is exposing our faces from many different angles. We will talk about the sun and the use of hard light to create visual interest in another post.
Photo courtesy of https://nofilmschool.com/2017/04/2017-led-light-shootout
The sky or natural light is an ideal soft key light, not only for it’s softness but also for its color accuracy. The picture from the test above is not the best example of soft natural light, since its a mix of both the sky and the direct sun. However, what's of interest here is the color accuracy of natural light. You can see the waveform of the sun measured on a spectrometer. Though natural light is balanced at 5600k or blue, its waveform is very balanced with rich saturation across the color spectrum.
As a one man band videographer, my goal is to create a simple lighting set-up where I can best replicate soft, natural light. Here is what I am looking for.
Color accuracy - high extended CRI rating, especially R9 readings which best reflects accuracy in rendering skin tone. High SSI value. Softness - I want to use diffusion to create a large area of even light with no hot spots Output – to approximate a window or skylight, I want the light to give me at 100FC (foot candles) 3 feet away, and over a broad area. Simplicity in Set Up - I want to be able to set it up quickly and with a small foot print.
LED based source To check off the boxes of color accuracy and output I really would be going with HMIs.
I’d recommend watching Robert Machado’s video on comparing video lights with SSI. SSI or Spectral Similarity Index is a nifty feature that let’s you compare two lights to see how well they match. Practically, what this means is that you can compare a daylight color balanced LED to actual daylight. There’s only a handful of people who review lights that own the Sekonic C-800, so there’s a limited amount of 3rd party tests out there.
Photo Courtesy of Youtube (Robert Machado) https://www.youtube.com/watch?v=xrEw-cJzExE
As you can see LEDs fair poorly in SSI readings. This is because they introduce green and magenta color shifts. The K6500 Joker 800 stands in a league of its own with an incredible SSI score of 94! The Joker 800 is an HMI light that produces plenty of output, more than most LEDs on the market. It’s the perfect light to be used if output and color accuracy is all you care about. However, it comes with a price. A hefty $7,300 price tag if you’re looking to purchase a new K5600 Joker mark 2. Throw in accessories and extra bulbs and you’re looking at about 10 grand. Of course you can find K5600 Joker 400s on eBay for under 2 grand.
But out of curiosity, I also wanted to see if I could produce soft natural light on a tiny budget
So I started looking for output and color accuracy amongst the LED market. LEDs introduce the advantage of low power consumption, low heat output, low weight, and low cost.
To replicate the pure output of an HMI I started looking at point source LEDs made popular by lights such as the Aputure 300D. These COB (chip on board) LEDs pack a serious punch. They are extremely hard, but can be diffused to create the soft light i'm looking for.
While the Aputure 300D checks many boxes, it doesn’t offer me simplicity in set up. There is a separate ballast and control unit and a mess of confusing cables. I’ve timed myself setting it up at a normal pace and it took me a whopping 2 and a half minutes! I know a PA (personal assistant) would take even longer to set it up, and that’s if they would be able to decipher the confusing array of cables.
That's a lot going on
The Mighty Godox SL-200W Luckily, there have been many companies trying to copy or outdo the 300D. I stumbled upon a review of the Godox SL-200W. What is so appealing about the Godox unit is that there is no external controller or ballast. Ultimate simplicity in set up! Everything is built into the light unit itself. Based on Curtis Judd’s Youtube review, its color accuracy faired comparably to the 300DII.
Photo courtesy of Youtube (Curtis Judd) https://www.youtube.com/watch?v=ZYhHMir5DVs
Color Accuracy The Godox's CRI R9 measured in at 94.4. It’s SSI score measured against daylight came in at 73. Nothing compared to the Joker, but on par with high end LEDs, and at a fraction of the price. The Godox lights can be purchased for about $360 new compared to about $1,100 for the Aputure 300D II.
Output The Godox output in terms of illuminance came in at 1800 FC, compared to 44,300FC for the Aputure 300D II. However, that number could be misleading. More on that later.
Drawbacks The main drawback of the Godox lights based on many independent reviews seems to be the fan noise.
Fan noise was not a deal breaker for me, I would be using these lights several feet in front of a large sheet of diffusion, which would also be several feet in front of talent.
I went scouring on the used market and was able to secure a deal for three Godox units along with some other modifiers. After selling off the modifiers the individual lights came out to about $150 each, which is a steal. Three units are great because LED lights from different brands do not play well together.
The best part about this deal is that all of the Godox lights had been modified so that the fans were virtually silent! At the time I made this deal I still had an Aputure 300D handy. The 300Ds fan noise coming from the ballast was actually way louder, noticeably louder than the Godox's fan noise.
So where do we go from here? These lights have a smaller output than the 300D and how are we going to manage to soften these lights up?