A Comparison of Light Fixture Output and Photometrics (Part Four): Plasma and Fluorescent Fixtures

In Part One we compared light outputs or photometrics of various tungsten fixtures. In Part Two we looked at HMI lights. In Part Three we looked at LED fixtures.

In this final part we’ll compare fluorescent and plasma lights. The following manufacturers are represented for fluorescent fixtures:

• Arri
• Mole Richardson
• Kino Flo
• Lowel

As far as plasma is concerned, the only representative is Hive Lighting.

If I’ve left out your favorite manufacturer or fixture, please forgive me. As far as I know there isn’t a similar comparison anywhere on earth, so I’m entitled to the most amount of mistakes.

Clarifications and caveats

Such a comparison cannot be completely accurate. There are too many types of fixtures, modifiers, bulbs and situations to make this scientifically accurate, so don’t expect it. Furthermore, nobody has the money to buy each and every fixture and modifier and subject them to controlled testing. Therefore, take note of the following caveats:

• Information in the chart might be inaccurate or plain wrong. For correct data, refer to the manufacturers’ websites.
• The ratings and figures are taken from the manufacturers’ websites, and no other sources. These ratings are as published by the manufacturers and might not factually bear out.
• When more than one bulb-type is available, I’ve chosen the one with the greatest output.
• Many models are left out because I don’t care about them!
• The red letter in the chart means the distance is below safe limits
• Do NOT make decisions based on this chart. Perform your own research. You are solely responsible for your actions.
• Just because some fixtures don’t show 120 V or 220V doesn’t mean the manufacturer doesn’t make them for those voltages. I couldn’t find info on it, that’s all.
• The voltages are gross averages. They can range between legally acceptable values, and this will slightly affect photometrics, as I’ve written in How to Estimate if your Lights and Gear will work on Portable Generators and the Mains Power Supply.

The chart

The chart is divided between manufacturers and fixtures. I’ve tried to find the footcandle and lux values at 20 feet, but some manufacturers prefer to rate their fixtures at different distances. Therefore, I’ve ‘normalized’ the reading to what it would be a 20 feet. I’ve included both numbers so you can make your own judgements.

Each light is compared to the Arri 650 Plus tungsten fresnel fixture, and the difference is written in stops. Negative stops means lower light output.

The final column lists the total lux output divided by the wattage, which gives us a pretty accurate indication of whether we are getting enough light by increasing wattage. Great comparison (if I say so myself), so I hope you find it useful. Here’s the chart (click to enlarge):

Whew, we have completed comparing all the major lighting types. What can we takeaway from these charts?

Takeaways

I could gather the following:

• An efficient lighting fixture in flood mode (or open face mode) should be able to deliver 1 lux/watt at a distance of 20 feet. If not, the light is not as efficient as it should be. This by itself could be a gold standard. As you can see from the tungsten and fluorescent charts, these lighting types fall well short of this standard. On the other hand, LED and HMI consistently deliver 1 lux/watt @20feet or more in flood/open face mode. Even plasma falls short, as can be seen in the above chart.
• The general beam angle (horizontal) in spot mode is about 10^o.
• The general beam angle in flood mode is about 60^o.
• The beam angle of an open face fixture is about 120^o.
• After a certain wattage, most lights start to become inefficient. Therefore, after a certain limit, it is better to club lights together rather than opt for one fixture with a higher equivalent wattage. E.g., two 1K tungsten fixtures will give more punch than one 2K fixture. Two 6K HMIs will give more punch than one 12K, and so on.

Which the best lighting type?

One can use different kinds of lenses, reflectors, grid and barn door combinations to ‘spot’ or focus a light fixture, so a comparison of light output at maximum spot is not very practical. For this reason I prefer to compare all lights in flood or open-face mode:

There can be no doubt that the LED lighting type offers the best lux/watt results. The worst are fluorescent fixtures, closely followed by tungsten. HMIs and Plasma are quite similar to LEDs.

Let’s see how much light output you get with 200 Watts (compared to a 650 Plus):

• Tungsten: -2
• HMI: 0.5
• LED: 0.5
• Plasma: 0.4
• CFL: -2

Clearly, HMIs are on par (pun intended) with LEDs, and plasma lights are not far behind. Can we declare LEDs and HMIs as the joint winner? Not yet. There’s one big surprise headed your way.

Price-wise, here’s what you would pay for a 200W fixture, on average (All except plasma are Arri fixtures):

What can we make out of it? On a $ per watt basis, CFLs and Fluorescents win by miles. In fact, even tungsten does better than LEDs, HMI and plasma. Now here comes the surprise. Even on a $ per lux @ 20 feet basis, fluorescents are cheaper than everybody else!

Tungsten is the worst but we already knew that. Here are the best light fixtures, highly generalized:

• Best lighting fixture in terms of $ per light output: Fluorescent 
• Second position: LEDs, which gives an equivalent amount of power compared to HMIs and plasma, but at a cheaper rate.
• Between HMI and plasma, I’ve got to give it to plasma for four reasons – no heat, no UV radiation, no ballast, and no need to keep replacing lamps.
• Tungsten is in last place. Though cheaper to run, tungsten is also the most inefficient.

If LED fixtures are to overtake fluorescent fixtures, they will have to come down in price by at least half. If that happens, nothing will beat LEDs (unless plasma takes over, but it’s slow going on that front).

Before we get ahead of ourselves, let’s come back to planet earth. Every light fixture type has one super power advantage that nothing else can replace. On the other hand, every light fixture type has a major disadvantage as well. Here’s a summary:

What do you think? Did I surprise everyone or what? Are fluorescents the best light fixture investments on the planet? Don’t believe me? A Lowel Rifa ex55 kit with three fluorescent bulbs costs about $400, and weigh 2.5 lbs. A 1×1 Litepanels costs about $770 and weighs 3 lbs. The Rifa gives half a stop more light output, through the softbox.

Fluorescents rule.