It takes time to get a camera and lens and specific lighting zeroed in. It's not an automatic function. At least not for me...

I love mixing up all the variables and starting from scratch. Move to a new type of light and it brings along its own influence on style. Change camera formats and you see your approach to shooting change. Work with a new lens and for a little while the novel new way of seeing the same subject means you compose a bit differently. 

On recent jobs I've been shooting with zoom lenses on an m4:3rds format. For the last week I've been shooting most things with the D7100 and the 85mm 1.8 lens. It's always fun to stir up the recipes. So, what have I noticed? Well, when shot at base ISO the Nikon has a smoother skin tone rendition than either the EM-5 or the GH4. I can duplicate the effect to a certain extent by using noise reduction sliders in Lightroom while adding some high frequency sharpening. At f2.8 with the 85mm I get backgrounds to go out of focus more quickly. The above image is pretty much out of camera. I did a slight amount of shadow recovery but no tonal changes or work on the background. What I'm seeing is a very nice rendition in the out of focus areas in the background. Also, the background is just eight feet behind Fadya and, at f2.8, is completely out of focus. I'm sure I can accomplish the same thing by shooting my 60mm m4:3 lens at f2.0 or nearly the same effect by shooting the 45mm 1.8 wide open. 

Also interesting to me is how well the above image handled high ISO. When I started my session with Fadya the camera was set to auto ISO with 3200 as the top end and 1/100th at the minimum shutter speed. This was not intentional. There are two different places in the Nikon menu that have to do with ISO and I just changed ISO to 160 in one place without remembering the Auto-ISO implementation. Since we were shooting in ambient light and locked to 1/100 as a minimum the camera defaulted to ISO 3200. I caught my mistake after a number of frames.

I presumed that the frames would be relatively unusable for my needs by decided to do a quick post process just for the heck of it. Apparently, starting with 24 megapixels helps in the grand scheme of things because after introducing a bit of noise reduction (and the noise at 3200 is just like the noise from the GH4 = tight, small black grains with no apparent color sparkles) and a bit of compensatory sharpening I was very happy with the overall quality of the file even at 100%. Interesting for me. 

While Fadya and I were playing around in the studio I did notice how quickly I kept hitting the buffer in the D7100. I'm used to the GH4 which slams out raws with wild abandon. The D7100 is pretty much locked into about seven frames before hitting the wall. I was shooting what I would consider worst case= that means auto distortion correction on, 14 bit file depth enabled and lossless compression set in the menu. While I am mentioning it here and it seemed to be a throw back to me I do have to make two points. The first is that the files are pretty enormous. Not "D810" enormous but the total amount information data tends to cube rather than double as resolution increases. Secondly, after having shot medium format film for years and having shot with four different medium format digital cameras (with one frame per second performance) the reality is that the D7100's pace is totally serviceable for a studio portrait artist. One just has to master one's cadence in shooting. And if you are doing it correctly there is a rhythm to every shoot. You just have to listen for it...

So, nice files with lots and lots of detail and (when the photographer sets the camera correctly) the wide dynamic range of the sensor means lifting shadows and keeping detail in skin highlights is that much easier. But what about my strange choice of lights?

If you've followed the VSL blog for long you'll see that I have an innate prejudice toward shooting portraits with continuous light sources. Until very recently I was pressing LED panels into service where possible. Last year I added four much more powerful fluorescent fixtures to the lighting collection and I've enjoyed using them. It takes a room with controlled lighting to pull the most out of the them because of the color mismatch with daylight and tungsten but as a primary light source for still portraits and video production they are a good addition. But the "holy grail" for continuous lighting buffs is a light source that really kicks out efficient light that's so close to average daylight that it's intermixable without heroic filtration. You want a light that does what the old fashion tungsten movie lights could do. That's to give you the flexibility of shooting with sharp, highly focused light or having enough power to pop the light through big diffusers and still get usable levels. 
In that way you get to choose between hard and soft. Something that's almost impossible to do with fluorescents and requires big expenditures to get with LED.

The lights I used with Fadya were the K5600 200 watt HMIs. Normally when I'm using continuous lighten the studio I block the outside illumination with black foamcore panels over all of the windows. This means there are no unexpected color shifts and it also means a total control over lighting contrast. With the HMIs I left the windows unobstructed. This allowed soft, non-focused light to come through. The HMIs were two or more stops brighter on Fadya but the combination of instrumented light and window glow lowered the overall contrast of the lighting and softened the effect on Fadya's skin. Interesting to me was the fact that the measured color temp. of the HMIs was 5400 + minus 4 green. That's pretty much nailed into accurate color. The percentage of green could be camera to camera variation as much as anything else (I have not had time to do an exhaustive profile of this particular camera yet...). 

Why continuous light instead of industry standard flash? I like the control that the continuous light offers and it is much easier on the subject as well. There's no constant flash to cause the photographer or subject's irises to continually stop down and re-open, which causes most of the fatigue experienced in a session. At slower shutter speeds there's nothing to freeze micro motions induced by breathing and the mobility of facial muscles. This leads to less clinical sharpness but a more realistic depiction of a subject. It's more in step with how we actually see and experience our external world that slices of unnaturally frozen and sharp flash work. Certainly, if you shoot dancers in mid-leap or fast moving children or some aspect of sports that might require (and accept) flash, you'll have different parameters to master. But photographing complicit adults is a whole different thing and one area in which the strengths of accurate revisualization, and lighting that's effectively ignored after a few minutes are good things. As is the slight softening of some details. 

HMIs are interesting to work with. You would think they are exactly like tungsten lights only balanced for daylight. But that's not exactly the case. They don't work by super heating a metal filament. Where tungsten lights (incandescents) work by apply current across a metal filament and heating it up till it glows HMIs work by creating an arc between two tungsten electrodes in a  high pressure atmosphere. They are much more efficient and generate much less heat. 

But they do require a "ballast" which is basically a box filled with electronic components that regulates current and voltage supplied to the electrodes. The ballast makes the whole construct much, much more expensive than conventional lights but the advantages are that you get a more comfortable working environment, daylight balancing, and higher output per watt of energy consumed. All the control of spot lights and other time honored tungsten constructs but with the energy efficiency and lack of heat that makes it a pleasure to work with for all parties. Is it any wonder that movie productions moved to HMIs decades ago? 

When I get my lights set up I turn on the switches on the electronic ballasts and it actually takes times, in fact several minutes, until the lights warm up and the arc becomes fully implemented and ready for shooting. It's novel to watch the warm up process as the lights go through color spectrum changes and go from vague and weak to full ready. 

The set of HMIs that I'm currently playing with are 200 watt fixtures. One is a fresnel spot light and the other is an open face.  Each accepts barn doors and a selection of different front lenses that can change the spread and the effect of the light. By changing the lighting pattern and by controlling spill with the barn doors the lights become very surgical and controlled in use. As I mentioned I used the open face light through a big diffuser for my main light and depended on the daylight coming in behind me and bouncing off the ceiling and walls as general fill. I used the fresnel spot (Alpha 200) as a background light, throwing a tight round pattern with very soft edges onto the dark gray canvas I used eight feet behind Fadya. 

There are differences that flash shooters will notice that take a little time and practice getting used to. The biggest difference is that there are no "level controls" on these lights. You have two settings: On and off. In the set up with Fadya the background light was to powerful compared to the main light. With a flash moonlight you would just turn down the power of the back light. What I had to do is cut the power of the back light using a black net. It took four layers of net to get the level that I wanted. Why didn't I just cover the light with diffusion material? Because it would have changed the spread characteristic of the light and made my tight spot into a broad flood. By using nets or screen material I am able to lower the overall level without changing the spread or the character of the light source. 

You make allowances for the tools you want to work with. I am awaiting the delivery of a third light this coming week. With the extra fixture I'll be able to do more complicated lighting set ups more easily. I'm also laying in a supply of metal screen material for additional level controls. One Tues. one of my good friends is using the lights to do production on some video interviews. It should be interesting to get his take on their performance as he's worked with these kinds of lights almost from the beginning of his career. 

I'm taking two of the lights with my on Thurs. for the start of a four day long assignment with lots of moving pieces. All Thurs. morning we're shooting more executive portraits in areas of flowing daylight. At some point the daylight moves and we need continuity. The HMIs in some giant diffusion should be just what the lighting doctor ordered.

I haven't done very much post processing to the images posted here of Fadya and I'll chalk that up to a busy schedule and re-entry into Austin this past week. But I'm pretty sure that you can see the effects I was working to get: A great smile, perfect eyes and the diminution of extraneous visual junk. 
Continuous lights and a different camera. Things that keep me from getting bored with the technical side of photography...


Racecar said...

Love the silky smooth skin tones this lighting/camera/lens combination produces.

Kitchen Riffs said...

Really interesting post -- I love reading how you light, shoot, etc. Those HMIs sound wonderful, although they're quite expensive (at least for me). I know they're on loan -- any plans to buy a set? Anyway, thanks for a fun read.
--John Griffin