Lighting question...Asking for a friend

Re: Lighting question...Asking for a friend

David Weaver

I would have somewhere between 15 and 20 of those lights (ballpark 50 lumens a square foot). I have the round ones with the shield and find that they don't make the same light as a similar rated - long fixture. Not being able to measure them, I suspect the actual issue is that they don't make the lumens they say they make and I'm blocked only by laziness in terms of plugging them into a kill-a-watt to see what their consumption is.

I tend to like bright light less than other people, so fi I come up short for a work area, I wouldn't be surprised.

Light and lumens

John K Jordan

>>>I would have somewhere between 15 and 20 of those lights (ballpark 50 lumens a square foot). I have the round ones with the shield and find that they don't make the same light as a similar rated - long fixture. Not being able to measure them, I suspect the actual issue is that they don't make the lumens they say they make and I'm blocked only by laziness in terms of plugging them into a kill-a-watt to see what their consumption is.

I tend to like bright light less than other people, so fi I come up short for a work area, I wouldn't be surprised.

The lumen value is a measurement or estimate of the total output of a light source in ALL directions so the amount of useful light that actually illuminates what you want can be significantly less than indicated by the specs, depending mostly on how much light the fixture itself blocks and these days, even more on the honesty of the seller. (To measure the lumen value the bulb or entire fixture must be placed in a very expensive integrating sphere - I suspect most lumen values advertised are estimates based on measurements of the individual LED components, not the entire fixture.) For example an integrated fixture that advertises a certain number of lumens may actually only provide 1/3 or 1/4 of that light where you need it. I take advertised lumen values with the same grain of salt as I do the notoriously ridiculous claimed HP of shop vacs.

An inexpensive light meter can help evaluate the actual light from fixtures and enable making useful real world comparisons. These meters will report the LUX value at a given point, only casually related to the lumen value of the light. (For consistency the light must be measured at the same distance from the fixture.)

I use this light meter: https://www.amazon.com/gp/product/B0075ZS8VQ

When I bought it the cost was less than 1/2 the current cost so there may be better choices now.

I also want more light than some: as eyes age they universally need more light. The change is so slow we never notice it. More light also aids in focus due to the increased depth of field as the pupil contracts. This can also reduce the effects of astigmatism. I use multiple fixtures, each with four 4000 lumen bulbs. I wire in zones so I can turn on the primary light fixtures only when needed. My fixtures also provide for easily lighting just two of the four bulbs in each fixture and lighting the other two only when needed. I use T5 fluorescent fixtures. One friend asked for sunglasses the first time he visited.

The number of fixtures and spacing depends on the amount of light wanted. A good way to determine this is to purchase one of one or more candidate lights and temporarily mount and wire them to evaluate the light at the work surface and the spread. Then decide. When planning light placement, don't forget that putting one in the wrong place may cause unwanted or even dangeroug bright reflections from shiny surfaces. For example, my table saw has a polished table surface.

I am also a believer in using task lighting at key work stations such as lathe, bandsaw, drill press, etc.

JKJ

Re: Lighting question...Asking for a friend

Bill Tindall, E.Tn.

I have guidance written up in the Articles.

Re: Lighting question...Asking for a friend

Curt Putnam

IMHO - more light is better, The older your friend is the more greater amounts of light will be appreciated. I'd be happy if my entire ceiling were light fixtures, albeit on several circuits.

Re: Lighting question...Asking for a friend

Jason Roehl

With LED lights, it never hurts to overshoot with the amount of light you need, then dim as necessary. LED drivers last much longer if they are putting out 80% or less of the current of which they are capable, and current = heat.

Jason

Re: Lighting question...Asking for a friend

Pete in Holland MI

Menards has 4' (guessing you did not mean 4 inch) fixtures in the 5-7000 lumen range. Will take less fixtures to do the job.

As others said, over lighting can be a good thing in some cases. Underlighting is a problem. You can always wire the lights in a couple different banks so if lower light is needed, fire up fewer fixtures.

Color of the room is of great importance too. Nearly white colors will bounce the light and make it overall brighter than just leaving the room natural wood & darker colors.