I have a variety of flashlights modified with wide variety of LEDs. I spent almost 2 days underground the last week and have some thoughts on LED lights (and Incandescent).
- 5K ish --- likely 75CRI --- Harsh, and because there is almost no blue in a cave, it did not even seem very bright
- 3K, 90 CRI (XPG) -- Good. No harshness. Good definition of colors in a cave, but lacked "depth" and visual acuity
- 4K, 90 CRI typical - Nichia219 -- Easily the best of the bunch. Good color definition, "bright" for the amount of lumens, good depth, good visual acuity. It was easily my favorite and worked well I found across a range of brightnesses
- Some of the other cavers had good incandescent lights and while they were "good", the 4K high CRI really caught peoples attention. I had a slide on diffuser on it so I could go from a tolerable spot to a bit floody with a very smooth beam. It was nice to have. I will have to make it more permanent for future use. It was great for lighting up larger features with a nice smooth beam.
Semiman
- 5K ish --- likely 75CRI --- Harsh, and because there is almost no blue in a cave, it did not even seem very bright
- 3K, 90 CRI (XPG) -- Good. No harshness. Good definition of colors in a cave, but lacked "depth" and visual acuity
- 4K, 90 CRI typical - Nichia219 -- Easily the best of the bunch. Good color definition, "bright" for the amount of lumens, good depth, good visual acuity. It was easily my favorite and worked well I found across a range of brightnesses
- Some of the other cavers had good incandescent lights and while they were "good", the 4K high CRI really caught peoples attention. I had a slide on diffuser on it so I could go from a tolerable spot to a bit floody with a very smooth beam. It was nice to have. I will have to make it more permanent for future use. It was great for lighting up larger features with a nice smooth beam.
Semiman