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Michael De Luca, CKD, ASID, NCIDQ
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We have added this page to answer any questions and to post FAQS based on questions submitted by users. Click on the "Send Your Question" below to submit your question or comment about LightCalc software or the book, "Kitchen & Bath Lighting... made easy"

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Q. Michael,
Your glossary states: cool = 3600k - 6500k and that warm = 2700k - 3000k. I read that daylight = [approx] 5500k. If that's true, then aren't the cool/warm temps reversed?

Michael Fisher

A. Dear Michael,

No, it just seems reversed. You are assuming that the higher the number the warmer the lamp. In fact, the higher the number the cooler the color. I know it is weird, but that is the way it is. For a more complete discussion on this read Chapter 2, Color and Reflectance. It should give you a firm handle on how and why color temperature works.

Let me know if you have further questions,

Q. Michael,

I took your class in Chicago at the KBIS and learned a great deal. I have been specifing Seagull undercabinet lighting for task lighting and like the flexibility of the product. Have noticed in our last job (especially since your class) that the Xenon 5 watt bulbs are too yellow. In checking Seagull's lamp selection chart I find that the bulbs that we have been using have a Kelvin rating of 2,550 which explains the yellowing. Do you have any suggestions for a more neutral color bulb that we could use? I've checked with our lighting supplier, and being in Kansas, we don't have a lot of expertise available. Is there any bulb that we could use in the exisiting Seagull track or at least make a change on our next home?

Thanks for your help,
Kathryn Focke, C.K.D.
Schultz Construction Manhattan

A. Dear Kathryn,

This is a problem, but possibly not to the degree you claim. However, reality is the illusion we perceive so let me give you some info to help you wend your way through this dilemma. Remember… all options have some advantages and disadvantages.

  • Festoon (Incandescent)--------approx 2,450k----warm color----10,000 hours life
  • Festoon (Xenon gas filled)----approx 2,800k----warm color----10,000 hours life
  • Festoon (Argon gas filled)-----approx. 2,950k---nuetral color----3,000 hours life
  • Bare halogen bulb----------------approx. 3,000k---nuetral color----3,000 hours life
Ardee makes an adaptor which allows the installation of the halogen bulb in a standard festoon clip. I assume that if seagull does not make something similar, that Ardee's unit might fit seagull. You are going to have to check to make sure. See our links page to get to Ardee's website. Their phone number is 704 482-2811 and 888 442-7333 toll free.

If you want to "whiten" up the color, it looks like your best choices are the Argon and Halogen options.

Hope this helps,

Q. Michael,
A strange subject, but let me explain. I have read your book regarding placement of recessed lights by countertops in kitchens (Chapter 3 - Spacing Principles). In the illustrations on pg 36 and 37, the recessed light is placed 39-1/2" from the wall. The reason of course is to prevent light scallops on the face of the cabinet. That's GOOD. BUT - when we have gone to a local lighting store and used their "simulator"* my wife and I find that with the recessed light in this position, we see a distinct "body" shadow on the countertop. Yes, the simulator had under-cabinet lighting. We observed that to eliminate (greatly reduce) the shadow problem required the recessed lights to be 18-24" from the wall. This unfortunately produced some of the light scalloping you mention in your book.

With the above in mind, do you have any recommendation on how to eliminate both the light scalloping and the shadow problems?

* Simulator - Real room with real cabinets and real lights. Recessed lights were placed at various distances from the wall, etc. There were different types of recessed lights and under-cabinet lights. All we needed to do was turn lights on or off to see the effects that would be produced.

Thank you,
Dick and Marlene

A. Dear Dick and Marlene,

Sounds like the simulator was quite stimulating and I see you have discovered a little something I like to call reality. Life is full of compromises and you have described one of them. There is no perfect solution to the problem you have encountered and you have described the pro and con of each mounting position. I recommend the solution found in the book; it is the best compromise. Be sure the simulator is using the types of lamps (candlepower AND beam angle) and trims you are planning on using. Otherwise the results will not simulate your results.

One question however, what was the beam angle of the lamp in the simulator? I'll bet it was no wider than 40 degrees. Most lighting houses standardize there. I like the 55 degree beam angle PAR 38 from GE (60WPAR38/HIR/WFL). It is halogen and with the wider beam angle, will most likely reduce the body shadow due to greater convergence at the same spacing. I also wonder about the type of under cabinet lighting used. Can you be more specific as to the type, wattage, spacing, etc.? I can be of further help with more info.

Hope this helps,

Q. Hi Michael,

I have been using your book and software for the past year and it has been very helpful in our electrical contracting business. Thanks for the inspiring work!

I am remodeling my own bathroom and have run into a lighting challenge. The room is 5x9 with all fixtures on the left wall as you enter. The pedestal sink is mounted between the closet and tub, midpoint along the wall. There will be a mirror similar to the one on page 132, Il. 6.41. I have thought about using fixtures on each side of the mirror, but also need overhead light. The ceiling above the sink is vaulted and is 6.5 above the top of the sink. How can I light the sink areaÐcans in the ceiling, pendants, or ? I have thought about sand blasting an edge around the outside of the mirror, and then back lighting the mirror, but am uncertain whether I can get enough light to take care of side lighting for makeup, etc.

Thanks for any ideas you can provide.

Don Gulliksen


Go ahead and use the sconce lighting on either side of the mirror to produce shadow fill on the face. For the vaulted ceiling, I have had very good luck with the low voltage recessed cans, MR 16, using the mirror light trim. Prescolite, Capri, and Nora all have low voltage, IC rated, 4" recessed cans sporting this trim. Right now, I like the Nora because it doesn't use a mirror, but has the same 90º x 360º adjustment. Due to the 90º adjustability from vertical, it can be placed on a vaulted ceiling and be directed straight down to the bathroom counter or even a piece of art on the wall (hint...hint).

You can see an example of this type of can on page 90 of the book (figure 5.26).

Remember not to place the downlight directly over the sink... it tends to give a decidedly haloweenish effect on the face.

Good luck,

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