8.31.2015

I went out to buy a gallon of milk but I came back with a new, inexpensive, high performing LED light that mimics open face tungsten lights of yore.

The RPS CooLED 50. The business end....

It will come as no surprise to VSL readers but I am a sucker for new lights. Especially new lights that can serve a purpose in my work and in my enthusiast projects. I left the house on Sunday to acquire some weatherstripping for my newly painted doors, and I think I was also supposed to buy some more milk while I was out but I got too close to the gravitational pull of Precision Camera and got sucked in due its powerful attraction. With entry a foregone conclusion I mentally prepared myself to experience inventory lust.  In the back of my mind I always have a subroutine working that automatically scours camera stores for rare, fun, awesome and underpriced lenses. I scanned and poked but nothing floated to the top of the pile in any meaningful way. 

I worked my way through novel stand cases which are always a necessity--- just because no one has ever made one that's just right. And they still haven't. I kicked the legs on a few, old school-style, aluminum legged tripods and ended up in a little helter-skelter niche that contained weird semi-system flashes, orphaned LED fixtures and vaguely interesting attachments. Always looking for the underdog I found a couple of boring looking boxes that had badly reproduced images of a weird looking LED light on them and, of course, I had to see what was inside. But I was a good customer. I didn't pull out my Benchmade pocket knife and go to town on the packing tape, instead I found a salesperson and asked if any of the product was out on display somewhere. "Noper." 

Could we open this box? "Yes indeed, we could." 

Inside, packed with protective cardboard, was a
funny light. It's the one imaged above and below. It's called an RPS CooLED 50 and it's packaging states that it puts out as much light as a 500 watt tungsten movie light. Maybe in some alternate universe where all the 500 watt tungsten lights are only used under heat proof blankets.... Nevertheless I plugged it in and played with it and it licked my hand and looked cute and I had to take it home with me.

So, what the hell is it?

It's an LED light that uses a concentrated (SMD=surface mount device) LED cluster that is more powerful than the traditional multiple, individual  5mm LED lamped panels. The major issue with most of the LED panels that we've used, especially the brightest ones, is that companies are using up to 1,000 individual 3-5mm LEDs, laid out over the surface of a 12 by 12 inch panel, and this "crowdsourcing" of enough LEDs  makes the panels bright enough to be effective for still photography and video. The big geometry of these devices always meant that it was very hard to get a sharp, specular light beam that would cast a deep and defined shadow. The diffused light of the one foot by one foot panels was soft and, used without diffusion, each little lamp cast a separate shadow and a separate light beam. Nothing at all like the conventional lamps, or even flash tubes, that we are used to.

The first SMD LED that I used, and have had a lot of experience with, was the Fiilex P360. It's a great little light and it kicks out a good amount of lumens but it's not capable of delivering the amounts of light that some of the newer compact light source models are capable of delivering. I continue to use mine almost every day but I have wanted to find a source of brighter (and cheaper) small source lights for a while. The RPS model fills the bill. The unit I am writing about here draws about 50 watts of power and is said to deliver the equivalent output of a traditional 500 watt tungsten light. While the output is quite exaggerated the CooLED 50 is still very efficient, and, in concert with it's polished 8 inch reflector (interchangeable and in a Bowens ring mount), it does put a significantly increased amount of light on subjects when compared to larger, flat panels I've used, or the P360.

This model comes with an A/C power block that fits into an accessory shoe under the body of the light itself but it can be replaced with external, 24V batteries as an option. The body of the light also has a connector on top to hold an umbrella in place. 

The SMD LED is compact and concentrated and gives a much too hard edged light for most lighting designs. The LED is covered with a removable glass cone that spreads light into the reflector efficiently. There is also an optional fabric "sock" available that fits over the front of the reflector, further softening the light. 

To maintain extended run times without heat issues the unit is fan cooled and most of the actual body of the light is covered with highly ventilated covering which should make any use of the unit around water seriously contraindicated. Lowering the heat load means that the light can run for a long time with little degradation to the components. 

Umbrella Connector on Top Matches with Hole in Reflector to Make Umbrella Use Practical.


The back of the CooLED 50 is pretty simple. An on/off switch and a five step dimmer switch. The dimmer switch is not infinitely variable, it's five discreet steps from full power to minimum power. The mounting yoke gives you a full range of movement even with the A/C power block riding underneath. 



After looking at the way the light is designed my biggest concern in actual use is that no one block the ventilation of the light by putting anything over the perforated surface of the main tube body. A cool running light is a happy light.

The unit came with a two door barn door set up which attaches securely. I looked at a Bowen's catalog of light accessories and there are lots of modifiers available that will fit this light. I'm not looking at any right now as my main use is to "push" the light through silk "flags" for diffusion which will allow me to use these, comfortably, as main lights for studio portraits. The same set ups also work well for video interview subjects.


But the real question is always about light quality. The manufacturer (Dotline) is rating this light at a CRI of about 90, a color temperature of 5200K (+/_ 200) and an output of around 5000 lumens. Specs that would have cost several thousand dollars only a few years ago. My first test was to see how it matched with direct daylight. I set up a camera with the WB manually keyed in at 5200K. I put a big chunk of white foamcore so that it was partially illuminated by direct sunlight through my window and partially lit by the CooLED 50 (that part of the foamcore NOT in direct window light but  well shaded from it). The light color temperatures were close with the LED being just a bit warmer but pretty neutral on the magenta/green hue axis. I would use the light unfiltered with sunlight or daylight balances. At five feet from the light, on axis, my Sekonic L-508 light meter gives me an incident light meter reading of ISO 100, 1/60th of a second, f2.8. While you won't be lighting up large buildings or overpowering the sun it is enough light in my studio to do nice portrait; especially if I use it fairly close in to the subject (always with diffusion). 

For the cost of $200 it's a pretty compelling light for the crossover work I've been doing lately. 
Here's a link for the light at Amazon > Affiliate Link for RPS CooLED 50

Tomorrow I'll be writing about this light's bigger brother, the RPS CooLED 100 which, as you might guess, is twice as powerful (that's only one stop more....). I bought the two with the idea that I'd mostly use the big light through a 4x4 foot diffusion scrim and the smaller light on the background to match the basic color. Make the set a pretty cool portrait duo for right around $500, total. 

Edit: Did my first portrait shoot with this light and its bigger brother, the RPS CoolED 100 today. The larger light was used as the main light and was aimed through two layers of half stop silk diffusion (4x4 foot) at the subject. The CooLED 50 was used with a diffusion cover over the reflector as a background light. I used my Fiilex P360 fixture as a hair light from the top of a tall Kupo C-Stand. The color temperature of the two RPS lights was matched and exact at 5200K. The final images required a +2 magenta tweak (which is minimal---) for exact color. That's closer to neutral than any of the flashes I've used....  I'm thrilled with the lights. Might get more.

Fine Print: I bought both of these lights for the marked, retail price at Precision Camera. I am not enticed or rewarded monetarily or with product by Precision Camera. I like to buy there to support a great camera story and to support our local economy. If you click through the link above or below and buy this light---or anything else for that matter----at Amazon.com the VSL blog will get a small commission. This commission is paid by Amazon directly and does not effect the price you pay for any product. Thanks! Kirk


10 comments:

Craig Yuill said...

Way back when, when I dabbled with studio portraiture, I made use of 250- and 500-watt tungsten bulbs with aluminum reflectors. I would have been all over lights like these. These days I rarely use lighting other than ambient lighting in photos I take, but I am glad that there are people out there developing lighting equipment that improves upon the old. Have fun with your new acquisition.

Nigel said...

When they're available on Amazon UK (& if you have the time), put up a link, & I'll bite.

mikepeters said...

Hey Kirk,

How loud is the fan for doing video interview work? Do you think it'll intrude with a shotgun or lav mic?

Thanks!

Kirk Tuck said...

The fan is pretty quiet. About the same as the fan in my MacBook Pro when it's just idling. In a very quiet room it might be picked up but I am sitting about four feet from the unit right now and can't hear at all over the noise of my G-Tech hard drive spinning. Outside ambient noise also masks it entirely.

Max Rottersman said...

How much do you miss the Fiilex's ability to variable dial in color temperature and/or intensity? It sounds like CRI-wise, you see no difference. Is that correct? Thanks for taking home those puppies!

Kirk Tuck said...

Hi Max, I'm using them like flashes as regards color temperature right now. The Fiilex P360 is very slightly warmer than either the RPS CooLED 50 or 100 but all three of them are a good match in terms of hue or mag/green axis shifts. All three represent the most neutral LED lights I have played with to date and are a good balance for skin tones. I shot a nice portrait of a doctor in my studio today. No direct sunlight but some ambient light from outside. Not an issue at all.
For the price I paid for the two new lights I am delighted. They remind me of my old, open face Lowell lights.

Richard Leacock said...

Looking forward to hear/see your thoughts on the larger units performance in conjunction with a video/photo shoot.
A stop more power you say? What would be your thoughts on using them for food/product shots?
And lastly, you did pick up that gallon of milk, right?...

Cheers

Kirk Tuck said...

Dammit. I keep forgetting the milk... Perfect lights for product and food, just perfect!

Michael Connell said...

Hey Kirk, I'll bring the milk if you let me visit the VSL studio to measure the light output of these things with my favorite modifiers (Westcott Apollo and soft silver umbrellas). :)

Milk processing equipment said...

Hi, it is fantastic and pretty fan. Keep it up to share such information about it that would be helpful for many people.