Incandescent bulbs (uncorrected colour ― 2400-2550K)

The scarcity of blog content the last few weeks is down to the fact that I’ve dived back into renovations put on hold last fall to preserve sanity.

Since then, I’ve put up with terrible lighting in my editing room, consisting of two bare incandescent bulbs on the ceiling, helped by halogen desk and standard lamps.

I never did install decent lights in my last studio (though I miss the picture rail!), carrying prints down to the middle floor for evaluation. I vowed this time things would be different.

Last month I began assembling components for a track lighting system. I’ve installed several configurations before, but this was the first I would need T connectors in order to create a H pattern. Since the electrical box was in the middle of the ceiling, I planned to run one 6 foot track across the (12´ wide) room and then, using T connectors, simply run track either side of those junctions.

That was the first iteration of the plan.

As I began installing the track — I bought five 6´ sections — I realized that the south wall didn’t need a full six foot length nearer the door, while the north wall would benefit from an 8-footer on that side. Laboriously, I took down the already-installed six-foot section and bought an 8-footer.

Lumicrest PAR20 High CRI “Apturi” LED

Now, I could cut the six-footer to zig-zag across to light the nonlinear wall east of the doorway. The remaining 6 foot track, cut down by a foot, was installed after the zig-zag. Of course, I had to buy two L connectors to accomplish that.

In the midst of installing the track, I also changed my mind about the kind of bulb I’d use. That required a change of light fixture to suit. My original choice were GU10 base LED bulbs … until I began to do more serious research into gallery lighting and I came across the high CRI Apturi PAR20 bulbs from Lumicrest Lighting Solutions in Toronto.

A high CRI (colour rendering index) assures accurate colour, a critical consideration when lighting artwork. The Apturi have a CRI of 95, compared to bulbs commonly found in box stores, which will have a CRI of around 80.

Additionally, the Apturi bulbs use a single integrated LED from Cree, considered leaders in LED development, and interchangeable lenses to vary beam angles from 25, to 35, to 60 degrees. The single LED reduces glare. Lumicrest has a handy beam calculator to figure out which lens best suits your space.

So, the Apturi it was. I chose 4000K (Natural White) colour balance. While these aren’t daylight equivalent (5000 degrees kelvin)*, I decided that 4000Ks were a good compromise between the warmer traditional lighting (e.g. 2700K) and the cold blue perceived above 4000K.

The distributors of the other components were good enough to cancel the order for the GU10 heads and order compatible PAR20 units.

Unfortunately, that didn’t solve the real problem I had with installation. Unknowingly, I’d accepted a track style known in the trade as “Lightolier” — the heads, of course, compatible.

I wouldn’t use this product again.

Centre track at box

Unlike “Halo” products, which have two copper contacts running on one side of the track channel and one on the opposite side, the Lightolier has a single copper contact on each side of the track. To my understanding, the one-per-side contact is not necessarily of any great functional disadvantage.

However, when joining the Lightolier-style product, via connectors, pushing the track onto the connector inevitably pushed the internal copper wire, housed in its plastic channel, out of the other end of the track. The only possible solution, discerned after many tries and uncounted expletives, was to pull enough of the contact channel out of the end of the track to be joined, carefully line the contacts along the corresponding copper plates on either side of the connector, then slam the track back over the contacts and onto the connector. If luck is on your side, the track will mesh without pushing contact channels out the other end or breaking anything else.

Try performing this procedure with neck craned to the ceiling, essentially working upside down. A borrowed telescoping support, seen in the photo below, was indispensable.

By comparison, in my experience, Halo tracks slide together without violence or obscene outbursts.

8 foot track (north wall) & T-connection

Once everything was up and bulbs installed — they arrived in the mail on Monday — I was more than satisfied with the results. Beside their practical merits, these LED lamps are a thing of beauty.

I also added a dimmer switch to the system. Good thing. Full power is not needed unless I want to light the whole room. For viewing works hung on the walls, half power from the (ten) 8W bulbs is quite sufficient.

I may even use these lights in the workspace to assess prints (the dimmer will come in handy here). While they are ever so slightly warmer than daylight, which can vary greatly in temperature according to atmospheric conditions, the high CRI rating may be more important than exact colour temperature in judging print quality. Ultimately, I can’t control the lighting conditions under which my prints will be viewed, once they leave my studio. The important point is to calibrate across my workflow.

Certainly, with this new lighting arrangement, existing prints exhibit a luminosity not quite seen before.

Mixed light: 4000K gallery lights, warm halogen (approx 2700K), blue dusk from window

*While the film industry often works at 5600/5500K, the graphics and photography industry has settled on 5000K as its default temperature. When editing, monitors are calibrated to the corresponding D50. A CRI rating of 90 or greater is recommended. For the technically inclined, the ISO standard 3664:2009 (pdf) is recommended as the colour viewing standard for the graphic arts.