Fore! As in, sometimes I feel like I need to hit people in the head with a golf club to make them adopt better technology. The one that has come to mind a lot recently is the comparison between the age-old 1K par lamp and the newer Source Four PAR fixture. Now, first, lets be clear that I’m talking about ETC’s Source Four PAR and not the Source Four Ellipsoidal (Leko) fixture that so many folks associate with the Source Four name. Next we’ll use the tired and tested Mole-Richardson 1K Molepar as the base model for comparison of photometric data. The Molepar has been around for decades and is a very nice fixture. I still see why some people would want to use it. However, the Source Four Par has eclipsed it in so many ways that in todays budget-conscious production world there are a lot of arguments for adopting the newer technology. The stage lighting guys had this figured out a couple of decades ago but the DP’s and gaffers in the film/video side of the business are sometimes slow to adopt and rightfully so in many cases. There’s a lot of money on the line and shooting schedules don’t allow for mistakes.
So, why one versus the other? To put it simply first, the Source Four gives you more light for almost half the wattage. How does it do this? Watts are watts, right? They must be intensifying the beam by focusing it in a smaller area or something right? Well, no. The Source Four fixtures use HPL bulbs. HPL means High Pressure Lamp and it’s that high pressure of the gasses inside the bulb that allow the tungsten filament to produce significantly more light than if that same filament were enveloped in halogen gas as it is in a standard tungsten-halogen lamp.
But wait, there’s more! One of the big advantages you’ll get when you rent from us is that the light comes with all four lenses. You get Very Narrow Spot, Narrow Spot, Medium, and Flood lenses. To do that with a Molepar, because the reflector and lens is a part of the bulb assembly, you’d have to carry four bulbs plus four spares. Each bulb costs about $25 wholesale. That’s $200 worth of bulb inventory for us to stack into a truck FOR EACH LIGHT. That takes up a lot of space and is a lot of hassle for you and us. The other advantages are that the Source Four Par can take either a 575 Watt or 750 Watt lamp. The 750 bulb really has some serious firepower.
The photometric tables from Mole-Richardson and ETC are attached but they need some deciphering since the distances of measurement aren’t exactly correlated and ETC used a 750 Watt lamp in all of their testing. I wanted to know the facts based on a 575 bulb in the Source Four Par. So, in doing that math for you, here’s what I found:
With a VNSP (Very Narrow Spot) bulb/lens at 30 ft. The Molepar put out a 10′ pattern at 200 footcandles. The Source Four Par put out a 8.6′ ft pattern at 283 footcandles.
With a NSP (Narrow Spot) Bulb/lens at 40′ for the Molepar the 19′ pattern had 65 footcandles. The Source Four Par had a 13.3′ pattern with 110 footcandles but at a slightly further 45′
With a MFL (Medium Flood) Bulb/Lens and at 40 ft. the Molepar had 25 footcandles over a 16×38 ft area and the Source four had 57 footcandles over a 16×22 ft area.
Finally, with a WFL (Wide Flood) Bulb/lens the Molepar had 20 footcandles over a 43×22 ft area while the Source Four Par had 35 footcandles over a 28×19′ area.
So the conclusion can be that the Molepar throws a wider beam at any given lens type but it has at least a third less brightness. Ultimately this means that with diffusion or a wider lens you’re going to get the same amount of light for half of the power consumption. You’re also going to get to have every iteration of lens choice sitting next to the light. Need a tighter lens? that’s a quick change. Yes, we know that Source Four Pars have a reputation for tough lens changes but we now send these handy little tools (https://www.youtube.com/watch?v=aQiRv5eLD5I) out with rentals to lens changes a snap.
One of the other failures in the original Source Four Par, when using it for film/video work was the lack of barnboors and that it didn’t offer the depth of a Molepar with a “can” on the front. Well, that problem is now solved also with the addition of City Theatrical’s new S4P barndoors and gel extender tubes (because the can was really always just to get the gel further away from the hot bulb to make it last longer).
At this point, if you’re not yet asleep by all of the technical jargon, you’re probably wondering that such a newer technology, with so many great features, and a much higher efficiency, must cost more to rent. Well, it does. $1 more in fact. So you can have either light with barndoors and a “can” for nearly the same rental rate. Here’s where the Source Four Par really wins though. 1K par bulbs are expensive, bulky and time consuming to handle. If you were to ask for all of those bulb options with that 1K Molepar we’d need to charge you extra for it. That would ultimately make the Molepar more expensive and harder for you
Thanks for taking the time to read this and I hope you now see clearly how a 575 HPL based par light fixture can be a much better choice for your next job.