A full spectrum Neodymium bulb is an ordinary incandescent light bulb, except that the glass shell is infused with the rare earth mineral element Neodymium, which is baked into it. It gives the glass a bluish/purplish/lavender tint. Some manufacturers avoid the more expensive and preferred fusion method of baking the Neodymium into the glass, and just apply a mixture containing some Neodymium, as a coating to the inside of the glass shell, much like that of the "frosting" applied to a frosted light bulb. This coating can be uneven and also separate from the glass, creating an inconsistant dispersion of the filtered or purified light. The fusion method also prevents the Neodymium from flaking away from the glass over time, regardless of how hot the bulb gets.

      The Neodymium filters out the excess yellow light produced by standard incandescents, but doesn't remove it completely. As a result, it brings out the truer color of objects, providing bluer blues and redder reds. Neodymium gives the light a bluish tint(enhanced white light), as it attempts to create a color spectrum as similar to that of the sun as possible. Colors are brighter and more vibrant. Skin tones appear natural, and visual acuity increases. It also reduces glare, which minimizes eye strain and fatigue. These bulbs greatly reduce the overwhelming and depressing yellow effect produced by regular standard light bulbs. There is a difference between incandescent and fluorescent lighting, and incandescent Neodymium bulbs should only be compared to, or measured against the incandescent bulbs they are replacing, and not to a high CRI rated fluorescent or direct sunlight.

      All that any light bulb or fluorescent can ever do is simulate sunlight. It can never produce it. Since full spectrum refers to direct sunlight, the most that any artificially reproduced source of light can do is imitate or simulate it. No bulb or lamp can equal direct sunlight, despite what some people who sell these would like you to believe. The truth is that all bulbs and lamps are full spectrum, in that they all(except for low pressure sodium lamps) produce light containing all the colors of the spectrum. The difference is in how much of each color is rendered by each lamp. So, for uniform industry wide identification and marketing purposes, all of these type bulbs and lamps are referred to as full spectrum. Except for the Neodymium, the bulb is the same as any equivilant regular light bulb.

      An ordinary bulb produces an excessive amount of yellow in the color spectrum. The Neodymium glass filters out most of it, as it absorbs the yellow spectrum from the visible light. As a result, the light is purified, allowing the values of the violet, blue, green, and red components to be strengthened, without producing an imbalance of one color over another. Without all of that yellow, a Neodymium bulb also appears to be a bit dimmer than an unfiltered incandescent bulb of the same wattage, life expectancy, and configuration. However, the lumen output of both are almost identical. For example:

Halco 60W A-19 Neodymium Full Spectrum bulb = 600 Lumens

Halco 60W A-19 Standard Incandescent bulb       = 590 Lumens

Halco 75W A-21 Neodymium Full Spectrum bulb = 710 Lumens

Halco 75W A-21 Standard Incandescent bulb       = 710 Lumens

Halco 100W A-21 Neodymium Full Spectrum bulb = 1000 Lumens

Halco 100W A-21 Standard Incandescent bulb       = 1050 Lumens

In any case, you get more colorful lighting and a better feeling to your lit environment with the Neodymium bulb. Neodymium light bulbs produce light as it is perceived from natural sunlight, and gives you greater color rendition as well as generating a brighter, whiter light. Neodymium glass has a narrow absorption band in the yellow and yellow-orange range, and glows with a whiter color like that of some halogen lamps. The special effect of the Neodymium light filtering, is to achieve a more balanced color output, for a light source of a given brightness and overall color. This causes objects to look slightly brighter and more intensely colored than usual. Ordinary light bulbs produce a harsh unnatural light, but Neodymium bulbs simulate full spectrum light similar to that of true daylight. If you're going to use incandescent bulbs, this is absolutely as good as it gets.