Now that we’ve established the potential pitfalls of fluorescent lighting, it was now my ambition to see if I could build an off-the-shelf lighting system using parts from Home Depot.  In some ways I was successful, and in others I faced some intersting limitations.

Knowing that the end goal is shooting some of the food we cook for my wife’s site The Fashionable Foodie, I decided that I would set a few parameters before shopping.  Since we’re both new at this, I wanted to minimize as many variables as possible.  We have very little experience plating, styling, photographing, lighting and setting scenery, so I thought it would be best to cut out table settings entirely.  I decided to begin by building a table-top cyclorama to shoot all the subjects on a plain white background for simplicity’s sake. 

I knew that I’d be able to obtain a workable sweep by purchasing some simple poster board at the craft store, but when I arrived in the posterboard aisle, I discovered that they also sold incredibly thin sheets of dry-erase plastic.  I was intrigued with the idea of shooting on a semi-reflective surface and it was only $1.99 a sheet, so I picked up a single sheet to play with.  I also grabbed a sheet of 20×30 white foamcore board for $1.50 and a sheet of white posterboard for 50¢.

In walking out of the store, the wind started to blow and the incredibly slick sheet of dry-erase plastic slipped out from my stack of items and I ended up stepping on the sheet.  Grrr.  I dented one side of it up pretty good, but pride prevented me from going in and buying another sheet.  Next stop was the Home Depot.

Note: the dry-erase sheeting comes with a gigantic 2″x4″ sticker on one side.  I ripped the sticker to shreds trying to get it to peel off before just cursing the whole thing.  Your experience might differ from mine, but that sticker ain’t going nowhere.  I just have to photoshop that part out if it makes it into a picture.

I already had some negative assumptions about Compact Fluorescent Lights (CFL) before I arrived.  What people don’t understand about them is that unlike a conventional fluorescent bulb, the ballast has to be built into the base of each bulb in order to make it compatible with existing Edison screw-socket lamps.  In a standard commercial fluorescent lighting fixture, the ballast alone is at least twenty bucks, in a film-quality fluorescent light, the ballast is at least half the total cost of the fixture.  The economies of scale dictate that the quality of ballast included in a disposable household fluorescent bulb can not be equal to the quality of ballast in a more robust fixture.

But what’s a ballast anyway?  Fluorescent lamps are really just a gas-filled tube that has an arc of electricity running through it, but there’s a negative differential resistance within the lamp.  This means that while lot of current is required to ignite the arc, after the current begins to flow, the resistance drops and allows even more current to flow.  This is where the ballast steps in to regulate the flow of current through the lamp so that it doesn’t run away.  Also, the larger the tube, the more voltage is required to ignite the lamp from a cold start and ballasts also have a system to ignite the lamp as well as regulate the voltage after ignition.

Even though I did not think highly of the CFL system for photographic use, I did not really want to get into the process of building a fluorescent fixture from scratch.  I decided that I would buy the best two CFL bulbs I could find and see what my results turned out to be.  

Entering the aisle of Home Depot where they keep the bulbs, I was a bit shocked to see that nearly the entire aisle was taken up by a single brand of CFL bulbs – “n:vision“, a brand I’d never even heard of before.  This certainly would work to streamline my choices, as I couldn’t really find any competing manufacturers products on display.  This kind of ubiquitous primo product placement made me wonder if n:vision might be the Home Depot store brand, but I could find no solid leads on my iPhone while standing in the aisle.

I did discover a promising series of traditional bulbs from Phillips under the “Natural Sunlight” product line.  These bulbs were marked with a corelated color temperature of 5000 K and a CRI of 92.  While the color is on the warm side of daylight, the CRI is incredibly high for a household grade fluorescent tube.  That being said, I’d already decided I was going to go with a CFL solution so I made a mental note and selected a CFL bulb instead.

I settled on the n:vision “daylight” bulbs.  I found a two pack of the bulbs for $8.97 and just decided that if they didn’t work out, they’d be fine to use in any other lamp in the house.  The package was listed as “100w equivilant” bulbs, 27 watt usage producing 1400 lumens.  In tiny print on the back, they listed “5500°K” with no CRI number.  I assumed this would not be a high CRI lamp, but decided to see what it looked like anyway.

The fixture I set out to mimic is the Lowel Ego light, but in examing the lamp’s design, I couldn’t understand why they were using a giant panel of diffusion in front of an already diffuse source.  Obviously, you greatly increase the surface area of your light by shooting it through diffusion, but I assumed you’d also be losing a significant amount of your already diffuse source when shooting it through more diffusion.  Because of this assumption, I decided to purchase two individual fixtures and use the lamps in an open-face situation.

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I found two low quality clamp lights that would fit the bill perfectly.  The two fixtures, both from Commercial Electric, were simply a plastic edison screw-socket fitted around an aluminum reflector, wire clamp and a 6′ cord.  I picked up one in an 8 1/2″ size and one in a 5 1/2″ size.  

Getting everything home, I decided to setup in the kitchen.  I taped one end of the plastic dry-erase sheeting to the tile wall about a foot up and let the sheet drop naturally into a sweep.  I screwed the CFLs into the fixtures and noticed the first problem: they stick out the front about an inch on each fixture.  Guess I won’t be able to lay these units face-down.  I started positioning them and immediately noticed my second problem: the clamps won’t grip to anything that isn’t shaped like a board.  The back of a chair worked perfectly, however the rounded top of our paper-towel holder caused the unit to droop and slip under the weight of the CFL.  Positioning these lamps was going to be a pain.

I fired up the lights and noticed the third problem.  When placed in these aluminum reflectors, the diffuse light of a CFL becomes much more directional then I expected.  (This is a “duh” moment for me.)  Where I expected the slightly unnatural diffuse omnilight of a Kino-Flo, I instead saw a very directional, if diffuse source…perhaps similar to an inkie shot through some frost.  Diffuse, but still very directional and casting some noticeable shadows on the subjects.

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Again, this is a point when I realize that shooting small objects is harder then I already assumed it to be.  I positioned a tomato on the acrylic sheeting and tried to start lighting it.  With such a small object, I found that I could light it pretty well, but I had trouble blowing out the white background and still keeping the subject properly exposed.  What I really needed was a way to position a light overhead, but given the constraints of the kitchen and the clamp lights, that wasn’t going to happen.

The CFLs are far more intense then I expected them to be and the clamp fixtures were really not suited to support the weight of a CFL bulb, perhaps those crazy Lowel cats were onto something when they designed that Ego light.

Pictured below is the tomato captured in the first lighting test.  I spritzed it with a bit of water to give it some much needed definition.  There’s just some white balancing in Aperture 2.0 and a little bit of exposure control.

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Decent for a first attempt.  A nice shadow at the foot of the tomato, a bit of a trailing shadow to the upper right side.  Some good specular highlights in the water and relatively good color reproduction.  The bad?  Well, the cyc isn’t lit evenly under the two source lights.  The sides of the tomato wash out, diminishing definition and separation from the background and the whole scene has a certain “tone” to it even after color correction.

In investigating further, I could not find reliable information about the CRI of the n:vision bulbs, but after shooting with them for a few days, I came to believe that they’d probably rank in the low 80′s.  There are some noticeable color casts in the green and somewhere in the blue spectrum that are very difficult to completely eliminate.  Pictured below is a completely uncorrected shot of some steamed clams.  To my eyes, there is a noticable yellow/green cast to the pale tones within picture.  The white point is not far off, but you can see some distortion in the yellow garlic and the coral tones of the shells.  The distortion seems to enhance the green within the yellows and mute the corals by diminishing the magenta tones – exactly what you’d see with a low CRI Cool White bulb, just to a lesser degree.

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For bright and vibrant colors, the color cast doesn’t seem to be very much of an issue, but for very light and near-white colors it is far more of a problem.  In the final picture that was used for this particular recipe, I struggled for a good period of time trying to remove the tarnished green hue from the garlic butter.  I don’t think I was fully successful in the end result.

Conclusions?

I’ve determined that it’s not really possible to build an acceptable lighting setup from your run of the mill big-box hardware store.  At least, not in the CFL realm.  

Manufacturers are generally not posting CRI numbers on their CFL offerings which generally indicates to me that they’re not going to be very good at color reproduction.  High CRI compact fluorescent lamps are sold online by many sites that offer “full spectrum” lighting, but you’re generally not going to find those same bulbs in your neighborhood hardware store.

Additionally, when placed in an aluminum reflector, the CFL lamps are far more directional then I’d expect.  If I were to redo this whole setup, I’d probably build something closer to the Ego setup with a large panel of diffusion to make a larger emission source.  The clamp lights are just too directional to be used as a single source, and too limited to be used in a multi-point lighting situation.  I plan to revisit this project and construct a ghetto version of the Ego lamp using some full-spectrum bulbs in the future and I’ll post my results when I get around to it.

Despite the obvious deficiencies, I was able to build a very affordable lighting solution that, although imperfect, allowed me to continue shooting food without relying on any natural lighting sources.  In the future, I’ll revisit this setup and see what I can do to improve functionality and color fidelity, but for the purposes at hand…it will do.

Totals:

• n:vision “daylight” 100w 2-pack: $8.97
• 5.5″ Clamp light: $6.47
• 8.5″ Clamp light: $7.47
• 1 Sheet acrylic dry erase sheet: $1.99
• 1 sheet white posterboard: $0.49
• 1 sheet 20×30 white foamboard: $1.50

• Total: $26.89