Shop Lighting

Recommended light levels for detailed to exacting work range between 100 & 300 foot candles. Many lamps will provide that at a fairly short range. The design of the fixture makes a lot of difference. How reflective is the interior surface? Is the shade designed to focus the light or diffuse it?

For drawing I used to use a c. 1947 drafting light. I couldn't get the circular florescent element for it, but it would accommodate a 150W incandsecent. At a range of about 18", the parabolic shape and the white enamel provided a good level of illumination. One other task light i used had a near mirrored inner surface. A single 100W was good at 18".

When I worked at an art museum, our "clean" room was lit by banks of modern high output florescent tubes, which provided slightly higher than 80 fc at work level. We kept 2 500W halogen work lights on hand when doing delicate work. The interior of the worklights was reflective, but not quite mirror like.

I've been looking at some of the contemporary LED systems. The quality of the light and the price/performance ratio has improved markedly over the last 10 years. They make ideal spotlights. So far I haven't found a system that does quite what I want, but the low power draw is very appealing.

cobalt said:

A few people have recomended led to me ,but would like to see then before purchasing them .its worth more to get a to be recomemded than to listen to a salesman

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Pictures that follow were taken by a very inexpensive digital pocket camera that does some automatic exposure adjustments. The images were cropped and assembled in Photoshop Elements and/or Apple Preview. Both of these programs are quite limited, and I don't think they can show exactly how the different lights compare.

The light sources were ambient early morning light on an overcast day, and the ground mostly covered by snow. The comparison is between that light and what is added by a 500W halogen work light, or 2 LED work lights each w. 80 LEDs. I don't know the illumination level produced by the halogen, but similar fixtures are listed between 5000 and 8000 lumens. The LED lamps provide 250 lumens each, total 500 depending on how they are focussed.

#1. A composite image showing a piece of yew illuminated at 5' by a 500W halogen work light, followed by the same piece lit by both LED lights at approx. the same distance. Then, the piece under daylight. The daylight shot was closer to the exterior windows, and taken a few minutes later in the early morning. The halogen light is obviously very "warm," while the LED is quite "cool." The daylight is from an overcast winter sky and the light reflected from snow cover. Also very cool, but the color seems acceptable.

#2. Descriptions of the human eye say that most of the nerves involved perceive intensity. Aka "Greyscale," the difference between light and dark. The second image shows the 1st image desaturated so that only the contrast info can be seen. The leftmost section, illuminated by the halogen work light shows how the camera tried to balance the extreme contrast. I think the image is useful because at that level of contrast, my eye interprets the same image with some portions flatend by glare, and others by shadow. Overall, flat compared to the lesser extremes of contrast produced by the LEDs.

#3. The 2 LED lamps are on either side of the work piece, both about 2.5' away. The level of illumination is more even, and the camera interpreted the color much better. My perception was similar. Good for close in work, I think.

The big downside of LEDs is still the upfront cost. I purchased the halogen work light for about $12. I did knock it over when it was still hot, and the bulb shattered. Add $4 to continue using. The 2 portable LED lights were $50. 10 years ago, similar LED lights, if available, would have been in the $200 range. A great improvement in cost, but still problemmatic. Shouldn't fail if dropped, and should last at least 5 times longer minimum than the halogen bulbs,

Upside is the the power consumption. These battery powered lights only need .15 A to charge. I suppose I could run both continuously while connected to the chargers. No need to rewire the circuit.

In the middle. Minimal heat waste. Using the halogen light in my unheated workspace releases enough heat that I can work even into cold weather. LEDs intrinsically create tight beams. As a detail/spot light they are great. They don't work as well for area illumination.

Right now, if I could get them, I'd still go w. about 500 W of daylight incandescent bulbs. A hundred up close, 250 from the right and 150 from the left.

Unfortunately, US law currently limits the wattage of incandescent bulbs. It seems 60W is the current limit, so when the older bulbs are sold off, a change to something different is a must.

Fluorescents continue to improve. Most new ones don't appear to flicker, and the color balance can be good. But they are diffuse by their nature. OK for area lighting. Not ideal for detail work.

When I was at the art museum, all the fluorescents outside the galleries were upgraded to higher output and better colored tubes w. better shaped fixtures. They were OK for the wood shop, but for fine work, I and my co-workers still kept halogen work lights on hand. A brilliant raking light helps volume perception. The galleries could not use fluorescents because even with filters, there was way too much UV that fades old pigments.

I recently spoke w. the fellow that had to take up some of my work when I retired from the museum. He continued my pilot work w. LED spotlights for illumination of art works, and changed all the halogen "Capsylights"to LEDs in the galleries. The accountant gulped when she saw the bill, but the time savings and low energy use will cover the initial cost in maybe 10 years.

Gee, I ramble on...

The LED work lights I just bought are surprisingly good.The color is good, and the illumination level is decent. Because they are spotlights, they are good for detail, not good for ambient light. At this point, I suppose a standard telescoping free standing work light using LEDs would work as well as a 500 W halogen, but they still are about 300% more expensive to buy. If you are working in a space that needs to stay cool, or doesn't have a strong electricity source (like mine) , I think they have become a good choice.