9.02.2014

Forget the viewfinder debates, we've got new HMI lights in the studio.

K5600 Lighting. Alpha 200.
This is a beautiful and compact HMI light 
that is also a focusable spot. It's a wonderful 
tool for finely crafted lighting. 


If you read the blog on a regular basis you've got to know that I have a soft spot for continuous lighting. I like using tungsten lights, LEDs, fluorescent fixtures and now, HMIs. But that doesn't mean for a second that I think you should abandon the ubiquitous photographer love affair with flash of all varieties. It's just that continuous lights provide such immediate results. It's so much easier to see the effect your lighting is having on a subject if the light hangs around long enough for your eyes to register what you are actually seeing. I'll go out on a sturdy limb here and say that continuous lights are the best learning tools for people who want to really, really learn how to light. Not just how to bounce some photons off a white ceiling but to be able to see definitive changes in outcome from seemingly small adjustments. Feathering an parabolic reflector is a good example. Finding the penumbra of light is harder when you use a modeling light or depend on trial and error...

If you are an event photographer then by all means, grab that SB-900 or that Canon Speedlight and go to town. You need to be untethered and mobile. And you probably want to freeze the action as your subjects freeze their smiles onto their faces. But, if you want to try your hand at still life or even portrait photography you might be pleasantly surprised at how flexible and satisfying it can be to work with light that sticks around. 

I love tungsten lighting because it comes in all shapes and sizes and some fixtures can project razor sharp beams of light while others, when used through big diffusion, can give the soft effect of northern light coming through high, thin clouds. The downsides of tungsten are that it consumes a lot of electrical energy which it converts mainly into heat and infra-red radiation. Tungsten also has a color temperature that is very different from daylight which makes balancing this light source with ambient daylight a bit more difficult than with most other light sources. You can easily filter it accurately but you'll need to worry about heat. A powerful tungsten fixture can melt a filter used too closely in minutes....

That's why a lot of people who work with continuous lighting have embraced LEDs and fluorescents. They are much more efficient with electrical energy and can be filtered or engineered to work in tandem with daylight. The weak spot for both of theses sources is both the lower light output you get with them and the discontinuous spectrum you'll get with all but the most expensive fixtures. (If you are using either source as your dominate light in a space with no daylight infiltration the color balance is not important as custom white balancing takes care of most spectral mismatches...).

The optimum continuous light would be nicely and accurately daylight balanced, strong enough to use in any ambient lighting situation and agile enough to provide many looks. While LEDs are encroaching into the film making space at a rapid clip the long time gold standard for most cinematographers has been the HMI light. 

So, what are they, really?  Here's what the Wikipedia says:

Hydrargyrum medium-arc iodide, or HMI, is the brand name of Osram brand for a metal-halide gas discharge medium arc-length lamp manufactured for film and entertainment applications. Hydrargyrum is Latin for mercury (Hg).
An HMI lamp uses mercury vapour mixed with metal halides in a quartz-glass envelope, with two tungsten electrodes of medium arc separation. Unlike traditional lighting units using incandescent light bulbs, HMIs need electrical ballasts, which are separated from the head via a header cable, to limit current and supply the proper voltage. The lamp operates by creating an electrical arc between two electrodes within the bulb that excites the pressurized mercury vapour and metal halides, and provides very high light output with greater efficacy than incandescent lighting units. The efficiency advantage is near fourfold, with approximately 85–108 lumens per watt of electricity. Unlike tungsten-halogen lamps where the halide gas is used to regenerate the filament and keep the evaporated tungsten from darkening the glass, the mercury vapour and the metal halides in HMI lamps are what emit the light. The high CRI and color temperature are due to the specific lamp chemistries.

The HMI light depends on an electronic ballast to feed the right voltage to the bulb which works as by creating an arc between encased tungsten electrodes. As stated above the typical HMI is about four times as efficient in electrical energy conversion than a tungsten light and by extension creates much less heat. One thing a bare HMI bulb does generate in ample amounts is UV energy which is why you must never use a bulb directly, you always need a glass lens (UV treated) between the bulb and human or animal subject.

The folks at K5600 Lighting sent me their latest small kit. It contains two different light heads and a ballast for each head. The heads take 200 watt bulbs which, theoretically, should equal the actual lighting output of an 800 watt tungsten light. It's hard to compare lights directly since the reflectors or fresnel lenses in front of them create different spreads and different intensities. But the overall advantage is a small light source with much more power and kick than an LED or a Flo and with a much tighter color spectrum match to daylight.

Along with the basic kit the folks at K5600 Lighting also sent along two extra bulbs. These are tungsten balanced and it's the first time I've ever seen tungsten balanced HMIs. I can only imagine this flexibility comes in very hand when mixes these lights on sets that are predominantly lit by conventional tungsten fixtures. They also sent along a collection of different lenses for their Alpha light which can be used on both fixtures.

HMIs are expensive. A single 18,000 watt K5600 fixture with ballast and accessories is around $18,000. (No, I did not add too many zeros) This little kit, with two 200 watters, retails at B&H for something a bit over $4,000. (edit 10/9, I originally wrote $6,000+ but I was wrong and have corrected this. Now that the kit is one third less (in my mind) it seems much more accessible to me. Sorry for the error!)  So who is the target market for this package? To be honest I'd love to have these two lights around the studio so I could use them interchangeably for both studio portraits and also video interviews in the studio and on locations. I'd actually want a third fixture so I could use one with a fresnel lens to "spot" a background while using one for a main light through big diffusion and keeping one in reserve for backlighting or fill. But they are out of my current budget. The folks who buy these are the movie rental houses. Places like GEAR in Austin.

These lights would rent out as part of a lighting package that a video crew would rent for a few days at a time to do specific projects that call for lots of mixed lighting scenarios.

The reason I like them is that the light spectrum is famous for making skin tones look incredibly good and for a good, long while HMI lights like these were the secret weapon for fashion photographers and very high end, editorial portrait photographers. I remember reading a "behind the scenes" article about the making of a Victoria's Secret catalog in which HMI's played a major part...



The back end of the Alpha 200. That's the fresnel spot.
See the knob on the lower right of the housing?
That's to control the angle of the beam.

I'm using the lights this month to do several portraits I've wanted to try. I love the look of continuous light portraits for the way the slower shutter speeds and the micro-movement of human beings fuses a sharp and less sharp image together into something that's hard to reproduce with flash. I'm also doing another restaurant video this month and hope to use the open faced fixture, the Joker But 200, in a Chimera Lantern modifier as my consistent main light to use in an kitchen that needs some lighting boost. With a solid light source in a 360 degree modifier my partner and I will be able to work through whole areas with enough extra illumination to make the difference between ISO 800 and ISO 1600. One stop may not sound like much but makes a big difference in noise profiles and color consistency. I've been testing the lights all day and I'm already sad at the though that they are "loaners" and will have to be shipped back......at some point. 


(Above) This is a light weight ballast. There's a ballast for 
each light fixture. The ballast supplies an even, accurate and 
clean voltage to the bulbs. These have massive heat 
sinks that keep the electronics cool. Important on 
projects that last for hours (or days). 

I have no idea why they are named, "Joker Bug 200." but the 
light fixtures are incredibly well made and use lots of
interchangeable metal parts. You can change the look 
of the light in many way and you can use speed rings to 
adapt Profoto modifiers to the lights as well.

I have the two light kit. My favorite set up is to use the fresnel (Alpha) fixture as a soft edged spotlight aimed into a dark canvas or gray paper background. I use the open faced Joker Bug with 
a lens that creates an even, centrally focused beam of light which I direct through soft diffusion materials. This lighting set up, combined with a fast, short telephoto lens, like an 85mm make beautiful portraits. Especially with the lens aperture used nearly wide open. My three test cameras are the Olympus EM-5 with an older Olympus 60mm f1.5, a Nikon D7100 with an 85mm 1.8 and the Samsung NX 30 with the 85mm 1.4. I'll try to get some good work done and posted so you can see the effects. 

In closing I must say that I find it strange that people have such strongly held opinions (myself included) about optical versus electronic viewfinders when so little attention is paid on the web to finer points of lighting and lighting tools. The lights make so much more of a difference that the different ways of lining up images in cameras with such similar sensors. In a finished image no one will be able to tell if you used an optical viewfinder or an electronic one (or an LCD screen for that matter) but the choice of lights and modifiers can make huge and very obvious difference. The various properties of lights and lighting can also have more nuanced differences as well. Funny that we don't discuss that in depth....




10 comments:

Fred said...

Kirk,
this is a very interesting post for me since I have been thinking about light a lot recently. I agree that it is more important than the sensor or viewfinder. No light, no picture. I will have to get some simple and inexpensive constant lights to play with and see what I can learn. Thanks.

Dave Jenkins said...

"The various properties of lights and lighting can also have more nuanced differences as well. Funny that we don't discuss that in depth...."

Talking about cameras is easy. Talking about effective lighting is harder, and doing it is harder still, because it's all much more subjective.

We buy cameras with higher and higher ISO capabilities because we think we can become better photographers without having to learn how to use light. And then we wonder why our photographs still suck.

Anonymous said...

If you pull the fresnel from the Alpha you will find a piece of clear glass. Using the fixture this way will give you very crisp shadows, like sunlight on a cloudless day. This could come in handy for some kinds of product shots.

BTW the Joker-Bug becomes a Bug when you lose the reflector for softbox use. Ain't jargon/argot wonderful.

Ed Posthumus said...

Kirk
If you want to talk nothing but lighting and the Art of Photography, I'm in. I can get my GAS elsewhere.

Patrick Stuart said...

Pro-level gear. I took a look at the price on B&H and realized that the basic light kit is more than the total cost of all my camera equipment.

Dave said...

What's the market for a kidney these days? I really only need one...

You hit a sweet spot for me here as I've always been fascinated with fresnel lighting, but ouch I don't think I can get off the porch and run with the big dogs if this is the price of entry.

I was hovering over the purchase button for an Arri 650 Plus for a while but seeing all the big lights in my basement that only get fired up 6 times a year already couldn't bring myself to do it.

If there are any places to discuss how to do this on a wannabe budget I'd love to know about it.

theaterculture said...

To an extent, I'd say that not talking about lighting is part of a really deep tension that runs back through the whole history of photography, and really through the arts in general, between Expressionism and Naturalism. There's a pretty deep Naturalist bias in a lot of photographic culture; it's arguably visible in our appreciation of many of the "hero" photographers like HCB and Cappa, who are seen as artists who look deeply into the world As It Is and seize something to freeze in a way that is both surprising and objective. That idea of photography prioritizes "capturing the moment," so the camera becomes the fetish object because it's the capture device.

The strength of that tradition can make the idea of staging what's in front of the lens seem intuitively "inauthentic." The film BLOWUP nicely illustrates this - the only meaningful image in the movie, around which the whole thing is structured, is a mysterious shot taken "in the wild" that might or might not show a murder, while the main character's work as a fashion photographer comes across as soulless and self-indulgent.

Patrick Dodds said...

Here in the UK there are kits of HMI's like the following:
http://www.theflashcentre.com/hedler-dx-df15-three-head-hmi-kit-i9917.html
I thought it was expensive but reading this post, maybe it's not as bad as all that.

Michael Comeau said...

In regards to Victoria's Secret, I believe you're talking about the great Sante D'Orazio.

According to an American Photo article, he used a 10,000 watt HMI so he could shoot at 1/250s handheld with a Pentax 6x7.

BTW, if you shoot women, you must view Sante's work.

Kirk Tuck said...

I have Sante D'Orazio's book and I concur. It's fabulous. I also agree that you'd have to shoot the Pentax 6x7 at 1/250th if you want to beat the ultimate in mirror shock.