Hi khallock. Real lighting novice here, just thought I'd share our recessed lights were installed today at 30" wall on-center, not 24". We will have upper cabinets. My GC feels 30" is better for light diffusion, including of the uppers and path through the kitchen. We will have good quality task lighting in the form of under-cabinet lighting as yourself.

On the bare wall side, my recessed are 29" from the wall. The wall starts being light about 12 inches from the ceiling. Closer will give you light higher up on the wall but a brighter wall. But what I have doesn't make any difference unless you use the exact same can, baffle and bulb. If you are flexible on your bulbs, you could drop the wattage (lumens) down if the light on the wall blasts you out of the kitchen. Norm, if you did 3ft and used a 4" fixture with narrow beam halogen how much light would you get on the wall? Thanks, Bob

Light sources have a spectrum. In some cases it is narrow, and in others wider. The sun, for example, emits through the entire visual spectral band, as well as UV and IR. tungsten and tungsten halogen are hot emitters with various spectral bands generally characterized by their apparent color temperature. The sun's spectrum is close to that of a 6000K (degrees kelvin) black body, whereas tungsten lights may be 2700K and tungsten halogens up to 3300K. The latter color temperatures are considered lower than the sun color temperatures, but are called warmer. Arc lamps that are spectrally broad may fall into the same color temperature range as the sun, but depending on line structure from the gasses used and the pressure that they are running at, may appear redder or bluer than the sun. Note that as these thermal sources are turned down with a dimmer, they become redder (warmer color) even though they are getting colder, physically. Now, getting to light emitting diodes, there are two types that I'm aware of being used for illumination (excluding variants). One type emits mainly at a single color, but because they are not true laser sources, this color band may be somewhat wide. Combinations of these sources may be used to try to match the tristimulus diagram of human eye response and look like a black body emitter at some color temperature. High color temperatures are considered colder because they have more blue; lower temperatures are considered warmer because they have more red. Note that this is referring to color temperature, and not LED physical temperature. The Cree LR4s had a scheme for re-balancing the color temperature as the LEDs aged. As I recall they were available in two different color temperatures for different applications. A clothing store, for example, might want a higher (colder) color temperature for interior illumination, whereas a kitchen might prefer something warmer (lower color temperature). (No one should be embarrassed if confused by this contradictory nomenclature.) Cree provided me a (proprietary) spectral chart that showed that their color spectrum was broad, but not particularly close to matching a black body spectral diagram. To avoid any post construction complaints I bought a single lamp and tested it against my soapstone and granite to ensure that the green highlights in each were being properly illuminated to provide a pleasing color balance when illuminated with the warmer LR4 option. The second type of LED source uses a deep blue or UV LED (or array of LEDs) to illuminate a phosphor or a combination of phosphors intended to emit a particular "whitish" color temperature. These phosphors tend to look yellow when viewed with the lamp off. By choosing the phosphor chemistry, and possibly over coating with filters, different color temperature sources are created. The goal is to know what color temperature one wants before specifying the particular lights to be used. If you want a tungsten halogen color temperature, specify 3200K - 3300K. For regular tungsten, 2700K - 2800K is good. Higher values toward 4000K will be bluer and more blue sky matching. As an aside, LG was able to cut the cost of organic LED (OLED) TVs by using all white (phosphor) blue-emitting OLEDs with red/green*/blue filters rather than the more difficult to manufacture sets of red/green/blue single color LEDs. kas *maybe yellow, I'm to lazy to go look

Location varies depending on the size and layout of your kitchen. I have an island in my kitchen and most of the recessed lights are in the walk area of the kitchen. In front of one set of cabinets the lights are 30" from the cabinet fronts but along the frig wall the lights are 20" from the cabinets. I also have undercabinet lighting plus 5 extra recessed lights over my sink area (it's a wide area). These lights are located 6" from the wall and butt up to the crown molding. I suggest you take your kitchen layout to a lighting store (not big box) and ask for their help. It's usually a free service. Make sure each designated area (sink , overhead and undercounter) has a separate light switch. Yes, I think you should put in the undercounter lights. :)