If you are looking into the ETC Source4WRD II LED Retrofit, you will find that there are three different variations of the retrofit.
When you are making your decision for which variant of the S4WRD II Retrofit to choose, you should think about three different components:
1) Amount of Lighting Output, as measured by Lumens
2) Color Rendering Index (CRI), which is how true to color are objects that being lit by the LED.
3) Color Temperature, what is the color of the light as it is produced. In this case there are two options: 3200K (warm) and 5900K (cool).
The following summarize each of these components, for each of the three Retrofit options.
1) ETC S4WRD II LED Lamp 3200K, 80 CRI Rating (S4WRDT120)-Source 4WRD II Retrofit Kit, which has the most light output at 11,430 Lumens. https://goknight.com/etc-s4wrdt120-source-4wrd-ii-retrofit-kit-120v/
This unit is using the "3200K Color Temperature", which is very close to a standard incandescent lamp, but the CRI (Color Rendering Index) is the lowest at just 80 CRI. This means that colors of items that you will light with this LED will have an 80% match to their true color.
2) ETC S4WRD II LED Lamp 3200K, 90+ CRI Rating (S4WRDTG120)-Source 4WRD II Gallery Retrofit Kit, which has the least light output at 9,716 Lumens. https://goknight.com/etc-s4wrdg120-source-4wrd-ii-gallery-retrofit-kit-120v/
This second unit is using the "3200K Color Temperature", which is very close to a standard incandescent lamp AND the CRI (Color Rendering Index) is very good at 90+ CRI. This means that colors of items that you will light with this LED will have a 90+% match to their true color.
That is why this model is called the "Gallery" Retrofit Kit. This is used in areas where the user wants the objects that are being lit to have a very true color rendering, such as a gallery, museum, art, or anything that wants the purest colors possible.
This unit stays at the 3200K Color Temperature, which is that warm, orange/yellow color that you think of when an incandescent lamp is dimmed.
3) ETC S4WRD II LED Lamp 5900K, 90+ CRI Rating (S4WRDDG120)-Source 4WRD II Daylight Gallery Retrofit Kit, which has the middle light output at 10,333 Lumens. https://goknight.com/etc-s4wrddg120-source-4wrd-ii-daylight-gallery-retrofit-kit/
This third unit is using the "5900K Color Temperature", which is very close to daylight and has more blueish-white in the color temperature AND the CRI (Color Rendering Index) is very good at 90+ CRI. This means that colors of items that you will light with this LED will have a 90+% match to their true color.
That is why this model is called the "Daylight Gallery" Retrofit Kit. This is used in areas where the user wants the objects that are being lit to have a very true color rendering, such as a gallery, museum, art, or anything that wants the purest colors possible.
This unit is different with a 5900K Color Temperature, which is that cooler, blueish-white color that you think of with a cool fluorescent lamp tube.
In Summary:
In regards to the light output, option 1 will provide you with the most light output, but will provide you with the least capability in Color Rendering Index.
The second option provides you with that warm color temperature and Color Rendering Index, but has slightly lower light output.
The third option changes color to 5900K Color Temperature (more blue/white light output) and the Color Rendering Index is very good, as well. The light output is also good, but not as much light output as option one.
If you have any other questions, or need help selecting the right ETC Source4WRD II Retrofit Kit for you, please feel free to contact us at 866-457-5937 or info@goknight.com.
Don’t forget that – no matter which S4WRD you choose – you will also need to choose the correct connector (bare lead, Edison, Stagepin or Twistlock) for your electrics and the correct color to match your existing fixture (black, white or silver).
Happy Retrofitting!