Light is a wonderful thing. I love light. I like things to be bright. Darkness is dingy and depressing to me.

But buying light is frustrating. Each company labels their light bulbs differently. So, it’s difficult to get the same quality of light if you’re switching brands or types of bulb.

When there was one type of light bulb everyone got used to referring to light bulbs by their wattage because, for the average homeowner, that was really the only differentiator besides shape. But guess what? The only thing wattage tells you is the amount of power your light bulb uses.

That’s great if you’re only concerned with how much energy you’re using. But wattage tells you nothing about the quality of light. Would you buy food based only on calories? A Snickers bar is the rough equivalent of two hard-boiled eggs. Just because they have the same calories, does that mean you’re getting the same nutrition?

For example, your lamp uses a 60-watt bulb, so you go for the CFL or LED bulb labeled, “60-watt replacement” or “60-watt equivalent.” But it’s too bright, too harsh, too yellow, etc. So, you blame all LED bulbs or all compact fluorescents thinking that the new bulbs just don’t look the same and those tree huggers are messing everything up again.

But, you aren’t comparing apples to apples. What should you look for to get the quality of light you’re used to, or want to see? Buy based on the BLT: type of Bulb, amount of Lumens and color Temperature.

Type of Bulb

Incandescent

Depending on your age, incandescent is the light bulb that most people know. Because most of us grew up with incandescent light, we tend to compare all other light to it. If light doesn’t look like the light we’re used to, we usually don’t like it.

Incandescent bulbs are VERY inefficient. Of the total energy they use, 90% goes to creating heat and only 10% goes to actually generating light. Yes, the individual bulbs are cheap, but 12 to 15 percent of an average home electrical bill is spent on lighting. So, that’s a big expense for you, and an even larger expense and carbon footprint when we total it around the world. Incandescent bulbs also have a short life; they typically last 1,000 hours.

Compact Fluorescents (CFLs)

CFLs were the first big wave of energy efficient light bulbs to hit the retail market. They initially sounded good. They were 75% more efficient than incandescents, lasted much longer—an average of 10,000 hours—and they weren’t too much more expensive. CFLs appealed more to people’s sense of doing what was right by the environment. They were willing to give up being able to dim their lights, having to wait for the bulbs to warm up to reach their full intensity and the harsh color of CFLs, because they felt they were doing the right thing by the environment.

But as more consumers switched to them, we realized we might be switching to the wrong side. Studies began popping up showing that CFLs contained up to 4 mg of mercury per bulb. In addition, they had to be recycled at specific facilities or local retail stores. And the instructions for cleaning up after a broken bulb almost required a Hazmat suit. So, how could this be a more environmentally sound form of light?

Light Emitting Diodes (LEDs)

The latest craze is LEDs. LEDs are 85% more efficient—which is why you find them in so many battery-powered applications. They last 25,000 to 100,000 hours. Unlike CFLs, they are dimmable and they are immediately full-intensity. They also produce very little to no heat. So, you can use them in sealed light units or in creative uses with paper and plastic where the heat from incandescent bulbs would have caused a fire or melted the plastic.

They’re also being combined with other technology like li-fi and sound, making them compact solutions, rather than just light bulbs. On top of all of those benefits they are considered to be the closest match to the quality of light generated by an incandescent bulb.

The only negative at this point is the cost–and, even that is coming down. They actually aren’t that expensive when you consider that you probably won’t have to change the bulb for 20 years. But, considering how often people move, unless you’re taking the bulbs with you, you may not want to make the investment.

Amount of Light

With incandescent bulbs, more wattage meant more light. But now that we’re dealing with energy savings, we need a different measurement of brightness. Lumens are the most crucial measurement of intensity. The amount of lumens tells you how much light you’re actually getting from a bulb–basically how bright it is.

The FTC requires that manufacturers include lumens on their labels. I don’t know if it’s old inventory or the FTC not policing their policies, but I see lots of labels without this critical information. The other problem you may run into is not knowing how bright your incandescent bulbs are. The FTC regulations don’t apply to incandescent bulbs. So, you may have no idea how many lumens to look for because you don’t know what your current bulbs are putting out. That makes it impossible to compare apples to apples. I’ve seen 60 watt “equivalent” labels, span anywhere from 400 to 800 lumens. So, judging the brightness of bulbs across incandescent, CFL and LED while only looking at the wattage equivalent, is like judging the height of three different breeds of dogs by the number of legs.

Here is a rough estimate of lumens per wattage.

If you don’t know what your current incandescents are putting out, you may just have to buy a few LED bulbs and make notes as to how many lumens you like/need, then return the ones you don’t like. Through trial and error, I have found that the CREE brand soft white light bulb is one of my favorites. It’s a reasonably priced LED bulb that has a very good light quality. And you don’t have to go anyplace special to get them. Your local Home Depot carries them. I’ve switched all of our light fixtures to them and my family hasn’t even noticed.

Temperature

The temperature of light sounds scientific, nerdy and like you have to be off the charts picky to even care about it. In the incandescent days it was mostly reserved for the interior designers and highly technical people who were looking for a specific result and didn’t want the colors and surfaces in the room to be changed by the color of the lighting. For the rest of us, it didn’t matter because most incandescent lights looked the same. But temperature is more of a factor in lighting today.

Ever hear someone say, “I don’t like that light because it just seems so cold and clinical” or “That light is really yellow”? That response is a response to the temperature of the light.  Temperature determines how light appears to the human eye. “Cool” light looks blue; “warm” light looks yellowish. The warmer the light, the more yellow it is; the cooler the light, the more blue it is. Think of ice and the sun.

It can be a little confusing. Color temperature is measured in degrees Kelvin (K). The word descriptions for the light will describe it in terms of warm or cool. But if you look at the actual temperature number,  the lower temperatures are the “warm” colors and the higher temperatures are the “cool” colors.

New standardized labeling will usually show both. So you can go by the descriptor (warm or cool), the numeric temperature (2700k here) or where the arrow visually shows on the chart range.

Incandescent bulbs typically fall in the warm temperature range—2700 to 2800K. So, if you are looking for a light that is similar to light from an incandescent bulb, or a warmer, more yellow light, you will want to look for a light bulb in this temperature range. To make things easier, if a package says, “soft white” it’s in this temperature range.

If the light bulb package shows a temperature of 3000 to 3500K, the light will tend to look blue because it’s a cooler temperature. Because it’s “cold,” light in this temperature range can feel cold and sterile. A package labeled “bright white” is in this temperature range.

If you’re looking for a neutral light that appears “white” instead of yellow or blue, look for light bulbs with temperatures between 3500K and 4000K.

It can be more important in commercial than residential use, but temperature does affect how colors appear. I have a friend in the print industry. He printed signs for a client and installed them. A few months later the client called him and told him that the signs had faded and now looked green. Nothing actually had changed with the signs. The company switched to fluorescent lights and the temperature they chose was changing the way the signs appeared. Ever hear someone say, “It looked different in the store?” That’s the lighting temperature. Try and get a sample for you to examine in your own home before making a purchase.

BLT

So, if the only thing you are shopping for is energy savings and you don’t care about how the light looks, just look at the label’s wattage replacement and pick the cheapest bulb.

But, if you’re picky like me and you only like a certain look to your lighting, or you’re trying to match what you currently have in an energy saving model, then you need to remember BLT–the type of Bulb, amount of Lumens and color Temperature. It sounds a bit overwhelming but, measured on these three things you will be comparing apples to apples. Once you find the amount of lumens and the temperature you like, the brand or price won’t matter. You can look for the same BLT every time. Take notes and keep them in a file on your phone or tablet so you always have them available.