Shadow box light query

Am I correct in understanding that the shadow box light is more yellow (about 20w cfl) than the studio lights (5000k)?  I want to make sure before I start painting as Mark states balancing whites is crucial. 
Appreciate any help from members. 


  • pitbull

    Welcome to the Forum.

    If you should choose to reduce your SB light by 20 watts it will not make it more yellow.

    I have 70 watts on the ceiling and a 17 watt SB light all rated at the color temperature of 5000k.

    Watts are a measure of heat. The better measurement of light output is lumens.

    The inverse square law of light describes the falloff of light with increasing distance from the source.
    At five foot distance you will get 4% falling on the subject. The SB light at two feet will deliver 25% of the light from the source.

    I suggest you aim for a balance in light strength and color temperature. Later, variations can be introduced using filters, colors and light strength.


  • Hi Denis,
    thanks for your reply. So I should aim for a 5000k sb light as well then. I was a bit confused about this but all studio and SB lights should be 5000k then if I understand you correctly. Thanks for clarifying this for me. I appreciate your help. 

  • SummerSummer -
    edited July 2019
    Hi pitbull,

    My husband and I are planning a new and better shadow box and the way he explained it to me is that would depend on whether the CFL bulb is also rated at 5000K (e.g. daylight vs warm white). With CFL or LED the intensity of the light is not related to the color temperature of the light. However, if you use a filament bulb with a dimmer to change the intensity, the actual temperature of the metal filament is changed by the dimmer so that the color balance does change with intensity. This does not happen with CFL or LED bulbs because their color is determined by phosphor emissions rather than the temperature of a tungsten metal filament.  Hope this helps.


  • Hi Summer,
    thanks. Yes that does help. I was confused about colour temperature and intensity, etc - it’s not something that I have ever needed to bother with.  I just replace bulbs in light fittings as needed.  
    Now i am aiming for several 5000k bulbs of different wattages to control the white in the SB. I think this will create balanced whites.  Then I can finally start painting 🤗
    Thanks to you - and your husband - for taking the time to explain this. 

  • I too am trying to figure out what lights to setup for the studio and shadow box.
    here is what I understand so far. Please correct me if I am wrong.
    Both the shadow box light and studio light should be around 5000K that is the color of the light.  From what I understand the bulb should be around 90 CRI .
    The lumens for the studio should be around 800 to 1000.    Not too bright.
    The lumens for the box should be much lower maybe even 200 or so.
    when using the color checker to check that your palette and the VALUE of the paint on your palette match you would adjust either the studio light or the shadow box light until the white value matches.
    what it seems like you’re doing there is making sure that when you are looking at color on your color checker as it is stretched out in your hand you are sure that the value of paint on your palette matches the value of the color in the shadow box?  
    It seems to me that it would be good to have a dimmer on either your studio light and or your shadow box light.  You are adjusting the light to match the value.
  • GTO

    I agree with all of the above. Suggest this is more easily achieved with LED light sources.


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