What color tempature lighting to use in home-made Spray Booth?

use daylight to make the light the most natural.

Thats what I thought. Thanks!

Ditto on the Daylight bulbs.

Jim 

This is a controversial subject.  This thread has come up many times about work bench lighting.  Here is my take on it.  For photography in outdoor situations, (I personally do use sunlight for photographing models) then a "sunlight" color temperature would be appropriate.  However, most of the time we view our models indoors, so fluorescent would be best (incandescent bulbs are disappearing).  So the trade is whether your paint should be optimized for realistic photography or for eyeball viewing.  Hard choice!

The most important characteristic of your lighting when painting is the Color Rendering Index (CRI); you want it to be as close to 100 as possible. Here is an example of a bulb with a whooping CRI value of 98, Philips TL950:

http://www.bulbs.com/product/F32T8-TL950-32W

Note that its color temp is only 5000K.

I am not sure whether any LED lights can match that CRI, though. Am curious to know, though.

I'm not sure why you would think temperature is relevant but wattage and luminence is more important. Don't use warm lighting for it make everything dim. Go with cool and or daylight bulbs since it 's more whiter than warm bulbs.

What ever you do, don't use halogen bulbs, They run too hot.

A strip light, like a fluorescent or an LED strip, illuminates more evenly than a point source or small source, so I am using fluorescent in my booth currently, but will probably switch to an LED string at some time.

I have a slit in the top of the booth, and the lamp is mounted directly above the slot. To keep paint from getting on the lamp, I have a rectangular piece of clear plastic covering the bottom of the slot.  To aid cleaning paint, I make my own tear-offs, strips of transparent "packaging tape."  I put down four or five of those strips, each with a folded-back tab on the end.  When the window/tape area gets too full of paint, I pull off the outermost tab/strip of tape.  I get a number of sprays with each strip.  When I have pulled off the last strip I make a new set.

I have strips of white LEDs lined along the edges and inside the spray booth and a single LED flashlight attached by magnet with a adjustable arm.  Really helps these aging eyes with seeing how good of a job I am doing with the AB.

Something to consider in lighting is how the end product will be viewed. Paints can look different under different types of lighting. Color temperature is is determined on a scale defined by the temperature of an ideal substance (as in a bulb filament) that as it gets hotter proceeds from red to blue. As a filament as in a bulb gets hotter from more input energy the light starts emitting a dull red light and with more energy input proceeds toward the blue end of the spectrum. It is measured in degrees Kelvin. Some typical sources are candle light at say 2700 degrees Kelvin. As the temp ratings rise the light becomes bluer with sunlight being about 5500 K. Light from a blue sky can be 8000 K. Typical home lighting is usually in the 2700 to 4000 K. range. LEDs without filters can be bluer than sunlight like +6000 K. Your booth should have some source simaliar to home lighting such as incandesent at 2700-3200 K or fluorescent at around 3200 K for Warm white or around 4000 K for coolwhite. LEDs are usable if filtered down into that range. Also some fluorescent lights can emit greener light at the same color temperature K.

Now that I have confused you I will recommend warm fluorescent lights or incandesent bulbs for viewing as that is probably how it will be viewed in the end.

One more factor for a booth is real temperature. Incandesents (Halogen or tungsten) emit much more heat than Fluorescents and LEDs are cooler yet. All of this is measured in Watts on the package. If color matching is not a factor LEDs get the most light per watt and are the coolest. Whatever works and more is better comes to mind.

Max

Hope this helps. As you can probably tell this was a great part of my career as a Photographer and final inspecting of print products under different types of lighting.

Hodakamax

Something to consider in lighting is how the end product will be viewed. Paints can look different under different types of lighting. Color temperature is is determined on a scale defined by the temperature of an ideal substance (as in a bulb filament) that as it gets hotter proceeds from red to blue. As a filament as in a bulb gets hotter from more input energy the light starts emitting a dull red light and with more energy input proceeds toward the blue end of the spectrum. It is measured in degrees Kelvin. Some typical sources are candle light at say 2700 degrees Kelvin. As the temp ratings rise the light becomes bluer with sunlight being about 5500 K. Light from a blue sky can be 8000 K. Typical home lighting is usually in the 2700 to 4000 K. range. LEDs without filters can be bluer than sunlight like +6000 K. Your booth should have some source simaliar to home lighting such as incandesent at 2700-3200 K or fluorescent at around 3200 K for Warm white or around 4000 K for coolwhite. LEDs are usable if filtered down into that range. Also some fluorescent lights can emit greener light at the same color temperature K.

Now that I have confused you I will recommend warm fluorescent lights or incandesent bulbs for viewing as that is probably how it will be viewed in the end.

One more factor for a booth is real temperature. Incandesents (Halogen or tungsten) emit much more heat than Fluorescents and LEDs are cooler yet. All of this is measured in Watts on the package. If color matching is not a factor LEDs get the most light per watt and are the coolest. Whatever works and more is better comes to mind.

Max

Hope this helps. As you can probably tell this was a great part of my career as a Photographer and final inspecting of print products under different types of lighting.

 

Max, the unit of measurement, watts, has nothing to do with temperature.  It is a measure of power consumed by an electrical device (a light bulb).  Basically it is computed by volts x amps.  It is used as a measure of equivalence of power consumption by incandescent bulbs versus fluorescent bulbs, compact fluorescent bulbs, and LED bulbs.

Rich, I meant this as a reference. Generally more watts=more heat. A 200 watt heater roughly gives off twice as much heat as 100 watt heater. A 13 watt flouresent that replaces a 60 watt tungsten gives some thing like 13/60 as much heat. Even though watts are not a measure of heat the are sometimes used that way for instance when you buy hair dryers and electric heaters. You're right, but it's kind of a generalization used which is not entirely correct.

In the photography and video business we always called the tungsten/halogen lights "hot lights", good for setting studio fires for sure. Strobes, flouresents and LEDs have replaced most hot lights due to their danger. When we lit areas we expressed how much brightness we wanted in watts. More watts, more light and the same whether correct or not, more watts, more heat, both in the electromagnetic spectrum as visible light or in the case of heat, infared light.

I now prefer warm flouresent bulbs for viewing and photography. They can match the color temperature of hot lights (tungsten/halogen) with much less heat and generally have a broader light source. The picture below shows a couple of different applications with flouresent light. LED banks are bright but expensive per watt and most are a much bluer source more matching daylight but can be corrected by filters.

Anyway I hope this clears up how watts, not being a measure of heat, can be used indirectly be used as such! Cheers,

Max

An update. LEDs for Photography are usually rated at around 5600K which is about daylight. To make them match warm flouresents and tungsten/halogen rated at 3200K a filter is needed. A bit of research reveals that some LEDs for photography can be dial adjusted from 3200K to 5600K which would be very useful in mixed lighting situations.

As for booths for viewing processes such as painting it probably doesn't make any differece what the color temperature is, however if the booth is for color matching, a source similiar to the final viewing of the product should be used. Heat and expense are certainly factors and with that in mind flouresents usually win. LED prices are falling and probably they will be the light of the future.

Whew! Probably more than you wanted to know about lighting but someone did ask! LOL!

Max

I pretty much aways try and have a white card somewhere in the photo when I take my pics. Then using my photo editor (I use Graphic Converter) I click on the white card (or even a white decal if it's really white) and use the "White Correction" function. That seems to take care of a lot of the bulb "temperature" issue for me.

Of course, your mileage may vary.

DDonSS3

I pretty much aways try and have a white card somewhere in the photo when I take my pics. Then using my photo editor (I use Graphic Converter) I click on the white card (or even a white decal if it's really white) and use the "White Correction" function. That seems to take care of a lot of the bulb "temperature" issue for me.

Of course, your mileage may vary.

 

Isn't that a great feature? In the days of film, light sources were modified or a filter was added to the camera lens to balance for the Daylight balanced film which was about 5500K. There was also a film balanced for 3200K tungsten light. With Daylight film and Tungsten lighting you needed a blue filter. Flouresent light needed a strong magenta filter to kill the green (actually the red missing in that type of light.) Even shade and north blue sky lighting required different amber filters. When shooting slides it was not unusual to carry 10 filters and a color meter.

I was certainly glad when that problem was solved and it happened not all that long ago. Of course since all of that, along with auto exposure, auto focusing, auto everything makes everyone a photographer---kinda, LOL!

Max

PS--Actually it's a good thing that opens photography to almost everyone! (kinda)  

Hodakamax

I was certainly glad when that problem was solved and it happened not all that long ago. Of course since all of that, along with auto exposure, auto focusing, auto everything makes everyone a photographer---kinda, LOL!

Or so they tend to think...