Finding Colour Temperature of Bulbs with Only Watt & Lumen Information

I have a some bunnings Luce Bella bulbs that I purchased a couple of years back, they are "cool white". I needed some more just recently and for some reason they have changed their temperature of "cool white" to be more warm/yellow. The new ones are 4000K. Any idea how I can find out what temperature these old bulbs are? I have the following information from the bulb, which of course doesn't show the temperature.

Luce Bella GLD023 Series 4.
9W 870 lumens.

I did try looking for a chart that shows watts+lumens=colour but can't find it.

Comments

  • Generally more lumens per watt gives a higher color temperature.
    Light is a spectrum, LED's are single frequency resonators.
    A white looking LED is usually a blue one with integrated yellow phosphor.
    Every manufacturer can basically brew their own, so matching them can be a challenge.

  • +1

    Take a look at this site https://www.lightingstyle.com.au/guide-to-lighting-colour-te…

    If the new ones are 4000K and more yellow you need something around 5000K.

  • +2

    4000k IS cool white though -

    Although confusingly, some people also reference 5000k and 6000k as cool white too.

    Also some suppliers class anything 200+- kelvin from 4000k as cool white too… 3800k would be warmer than 4200k which seems 'cooler' than standard '4000k'

    I remember back in the day I had an android app that was pretty accurate at telling me what kelvin a light was … but for the life of me can't remember it - havent used android for years.

    • 4000k is neutral white where I’m from.

      • We also call it natural/neutral where I work but most if not all we deal with call it cool

        • Tell them they’re wrong!

          • +1

            @mapax: tell a sparky/builder/designer/project manager he's wrong? do ya want to be hit with some f words? haha

  • Incandecant lights (old) = 2700k
    Warm white globes = 3000k
    White = 4000k
    Cool White = 5000k or higher

    Warm white for bedrooms/living areas.
    Cool white for bathroom and kitchen(working areas).

    Watts is how much power it uses
    lumens is how much light is produced
    Kelvin (eg. 3000k/4000k/5000k) is the colour temperature.

    • Cool white for bathroom and kitchen(working areas).

      Why? IMO this makes my face and food look like crap. Much rather warm white almost everywhere in the home.

  • My guess is any calculation from watts and lumens is too inaccurate, especially if you’ve read those specs from a box. Besides them being rounded off, the marketing department has more sway than the engineering department as to what’s on a box.

    Unless you can find a way to measure the existing light output I suspect the only way to Marc them is to actually get them side by side with anything you intend to buy.

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