Shop Lighting

[David Kreuzberg]

I'm running low on T12 replacement tubes, and am going to switch to direct-wire T8 8 ft. LED tubes. The bulbs I'm looking at are 4,200 lumens and come in 3,000K, 4,000K and 5,000K. I can't decide between the 4,000K and the 5,000K.

The shop area in my building is approximately 30 ft. x 40 ft., with three banks of four two-bulb 8 ft. fixtures running parallel to the long side. The shop has metal walls and ceilings. Ceilings are 10 ft. and both walls and ceiling are an off-white, cream color.

The existing fluorescent tubes have 4,400 lumens and are 4,100K. They provide plenty of light.

Would the 5,000K LED tubes be overwhelming?

[Ken Fitzgerald]

David, I put 5,000K T-8's in my shop. When a few started burning out, the only replacements I could find locally were at 3,500K. I miss those 5,000K lights. As soon as this box of replacements are gone, I'll switch to 5,000K leds!

[Art Mann]

5,000 Kelvin looks entirely to blueish and unnatural to me. I'm using 2700 Kelvin. That is the same color is bright incandescent lights.

[Peter Christensen]

Midday daylight is about 6500K. As you move towards morning or evening the number gets lower (warmer). I have 6000K lights in the shop and when walking in from the warmer light of the house in the evening it seems bright/harsh for a few seconds, then I adjust and it doesn’t bother me. If I come in on a sunny day around lunch I don’t notice any difference. I’d get the 5000K but your preference may be different.

[Greg R Bradley]

The difference is just going to be the color, with 5000K more likely to be "blue-ish". Honestly, I would think it is likely to be fine either way.

A bigger concern will be the harshness due to the more directional nature of most 8' T-8 LEDs. I used clear plastic one row LED hung at 15.5" in one shop area and they are a bit obnoxious. Frosted will be less obnoxious. The long awaited T-12 3 row at 120* LED will solve the problem but I've been waiting 2 years now. You are going from a 1.5" bulb with 360* light output to a 1" wide bulb that likely shines all light down.

Are they bare bulb fixtures?

I have many, many T-12 where I've not been able to find any LED that are acceptable due to glare and desired dispersal of light. At 10' and 7-8' between rows, you may have unacceptable light dispersal.

Now if one row is directly above a row of workbenches against a white wall, they may be wonderful.

[Jim Becker]

All of my LED lighting in the shop is 4100K and I'm pleased with it. 5000K feels "too blue" for my taste, but...that's a personal preference thing.

[David Kreuzberg]

David, I put 5,000K T-8's in my shop. When a few started burning out, the only replacements I could find locally were at 3,500K. I miss those 5,000K lights. As soon as this box of replacements are gone, I'll switch to 5,000K leds!

Ken -

How long after you installed them did they burn out? I thought T8 LED tubes are supposed to last a million + hours???

[David Ruhland]

Putting my photography lighting instructor cap on here i will try to clarify one of the most confusing numbers- the Kelvin temperature you are talking about.

First off, my shop lights came with 4100K 4000 Lumens bulbs. They are fine for woodworking and are dam bright! The Kelvin temp has nothing to do with the brightness of the bulb I personally like 5000-6500K and will explain why shortly.

Brightness has to do with the amount of Lumens. Next time you are at your local big box store take a stroll to the light bulb isle ( I call this the isle of confusion) look at the labels on the bulbs. Grab a couple 100 watt replacement bulb from different mfrs for example and read the label- esp notice the lumens you will notice not all bulbs are created equally. I have seen as much as 800 lumens per bulb difference from mfr to mfr.

This "looks to blue" " looks to yellow" for my liking comment is really confusing as well because right now you may see light as light, however have you ever been driving down the road at night and had a car come at you with two different looking headlights? one is kind of yellow, the other so white that you can hardly see? This is a perfect example of the Kelvin Temperature the one that is "yellowish" looking has a Kelvin temp of approx 2700K, the white/blue looking one has a Kelvin temp of 6500+

I am sure you have seen light fixtures in stores that have that "odd color" bulb in from the rest of the lights? That is because the replacement bulb Kelvin Temp is different than the bulb that was replaced. Most bulbs have Kelvin Temp written on them somewhere.

Why do i like 5000 K lights? I do a lot of camera work ( both still and video) of new products and my studio lighting is 5000 Kelvin. I also leave the ambient lights (ie the shop lights overhead) on If i forget to set the white balance on the cameras i get a blue or green tinge to my images due to the color shift so i like to keep everything the same Kelvin Temp. Hope this helps in your decision making process. I am sure you have taking pics with a digital camera and had them look green or yellow?

Remember Kelvin Temp has nothing to do with brightness, Lumens are brightness. The higher the number of Lumens the brighter the bulb.

Now head on down to your favorite big box store go to the lighting isle and tell the kid working there you want to look at T8 5000Kelvin bulbswith at least 4000 Lumens options and get a look on his/her face :-)

I bet you will all be looking at light bulbs differently now? LOL

[David Kreuzberg]

David,

I understand the lumen/Kelvin relationship; I was concerned that 5,000K would make me feel like Jim Becker does about the "blue" quality of the light.

[David Ruhland]

David,

I understand the lumen/Kelvin relationship; I was concerned that 5,000K would make me feel like Jim Becker does about the "blue" quality of the light.

As Jim says its a "personal preference" thing... I think you would be happy with either one....

[David Kreuzberg]

Thanks, David. Your article was very helpful.

And thanks to all for their insightful observations and advice!

[Ken Fitzgerald]

Ken -

How long after you installed them did they burn out? I thought T8 LED tubes are supposed to last a million + hours???

My 8' tubes are T-8 fluorescent bulbs, not LEDs. When my current bulb supply runs out, I will determine whether or not to use more bulbs or switch them over to LED tubes. Regardless, the 5,000K is what I prefer. There is not right or wrong....it's subjective...it's your personal preference.

[Jim Becker]

As Jim says its a "personal preference" thing... I think you would be happy with either one....

Yes, very much a personal preference thing. If I spent a lot of time in a 5000K environment, such as the photography studio that you reference, I suspect that my preference would be different. I do need to clarify that my stated preference is partially influenced by the general marketplace...when one I buy and work with different kinds of fixtures for my home and shop, the availability of products stating 4100K is fairly generous. Same for 2700K. (which I use in bedrooms and gathering areas where softer light is preferential) 5000K seems to be a smaller market for household-oriented products in my experience. So in the interest of consistency, that's how I kinda landed where I did. The LEDs I've installed on my vehicle, however...are all 5000K

[Joe Jensen]

David, For me low CRI bulbs are horrible. Getting to a higher CRI (accuracy) requires more doping of the LEDs which adds cost, and it lowers efficiency. With fluorescent bulbs, a 93 CRI bulb will have as much as 30% lower lumens per watt. But reds will look red and greens will look green. Typically photographers want 95 CRI or higher. Color temp is adjustable with white balance, color linearity or accuracy is harder.

Putting my photography lighting instructor cap on here i will try to clarify one of the most confusing numbers- the Kelvin temperature you are talking about.

First off, my shop lights came with 4100K 4000 Lumens bulbs. They are fine for woodworking and are dam bright! The Kelvin temp has nothing to do with the brightness of the bulb I personally like 5000-6500K and will explain why shortly.

Brightness has to do with the amount of Lumens. Next time you are at your local big box store take a stroll to the light bulb isle ( I call this the isle of confusion) look at the labels on the bulbs. Grab a couple 100 watt replacement bulb from different mfrs for example and read the label- esp notice the lumens you will notice not all bulbs are created equally. I have seen as much as 800 lumens per bulb difference from mfr to mfr.

This "looks to blue" " looks to yellow" for my liking comment is really confusing as well because right now you may see light as light, however have you ever been driving down the road at night and had a car come at you with two different looking headlights? one is kind of yellow, the other so white that you can hardly see? This is a perfect example of the Kelvin Temperature the one that is "yellowish" looking has a Kelvin temp of approx 2700K, the white/blue looking one has a Kelvin temp of 6500+

I am sure you have seen light fixtures in stores that have that "odd color" bulb in from the rest of the lights? That is because the replacement bulb Kelvin Temp is different than the bulb that was replaced. Most bulbs have Kelvin Temp written on them somewhere.

Why do i like 5000 K lights? I do a lot of camera work ( both still and video) of new products and my studio lighting is 5000 Kelvin. I also leave the ambient lights (ie the shop lights overhead) on If i forget to set the white balance on the cameras i get a blue or green tinge to my images due to the color shift so i like to keep everything the same Kelvin Temp. Hope this helps in your decision making process. I am sure you have taking pics with a digital camera and had them look green or yellow?

Remember Kelvin Temp has nothing to do with brightness, Lumens are brightness. The higher the number of Lumens the brighter the bulb.

Now head on down to your favorite big box store go to the lighting isle and tell the kid working there you want to look at T8 5000Kelvin bulbswith at least 4000 Lumens options and get a look on his/her face :-)

I bet you will all be looking at light bulbs differently now? LOL

[David Kreuzberg]

I see. I guess I assumed you were talking about LED tubes.

I'm looking at 8 foot direct-wire LED tubes. From speaking with the supplier, they're ridiculously easy to install. They're pricey at $19.00 per tube, BUT - there is no retrofit kit involved. Just eliminate the ballast and wire nut hot to one end, neutral to the other. The tubes use the same single pins as the T12 lamps.