I’ve put this in the 18650 section, but my question is for every cell.
CRI 60-95
1-1000lm
2000-6500K
That color looks too red, green, …
Flooder - thrower
Now imagine your main task in life is reading labels on boxes, cans and old machinery.
When is text most readeble? When it really pops out?
Sure the perfect tint that mimics daylight is great, but if you look beyond “I hate that tint” what’s best for the given task.
If your life would depend on label reading what would be your choice?
Does readability always benefit from high CRI?
Does the ideal tint depend on the color of letters you have to read?
This isn’t a “which brand is best” thread, not yet at least. I want to learn what to look for when searching for my ideal light.
I think it’s like anything…color temp and contrast will matter the most, and sometimes simply the angle at which the light is held compared to your viewing angle (like on old machinery placards). Sometimes that ugly cold blue actually works better in certain scenarios but it can be rough on the eyes if you have to use it for long periods and/or up close. I’d say go high CRI in something with a color temp you prefer and that has lighting modes/ramping that get you where you need to be…also beam pattern. You may want a smooth floody mule-ish beam depending on your labels, or it may be best to go with the usual balanced beam that has a spot and good spill light.
As a for-instance, when working with metal up close, sometimes I want my usual 5000K-ish color temp (high cri or not) but there are lots of times when a lower 4000K or even lower temp is much more helpful. Some of that depends on surface finish and also ambient lighting.
Lots of labels in the world…anything notable about what you’d be working with?
Flickering can cause eye strain. Same as screens. Without measurement its almost impossible to detect s**t light Whats why every home have to get something like OPPLE.
I spend a lot of time behind a screen and I agree that quality isn’t always obvious.
Sometimes it’s impossible to see a quality difference but if you use the screens for extended time somehow, for a reason you can’t define, the quality screen feels better.
I’m not so sensitive to flicker it seems. 100, 140, 200 Hz screens I don’t notice much difference.
But a low blue light screen makes a whole difference. When brightness on a low blue screen is up, it’s just bright. But on screen without a bluelight filter my eyes burn out.
I threw away my Zebra headlight. Costed me >$100 but flickered more on low than a $1. Truely a same. I often find ZL that meets all my specs but the flicker still scares me away.
I’m not sure it has anything to do with readability but warm colors seem to be more relaxing.
If you want to create a cozy romantic situation in your house, nobody with go for 6500K but likely go a lot closer to 3000K.
Sometimes it’s nearly impossible avoiding some reflection when reading labels. For example those glossy labels on spray cans. Could it be that 3000K reflections somehow affect your vision less than 6500K reflections?
Computer screens flicker constantly and that doesn’t stop us. I think I would worry about PWM in a reading light only if I was having trouble sleeping after using it.
That placard example is exactly where I think holding the light at a low angle to create shadows (hopefully) of those shallow-stamped characters is most helpful, and personally that’s where I like lower temp lights as well. I guess you can’t control the ambient lighting there but with so much other light to deal with that can make it harder to see it clearly - you might experiement with some cheapy cold white lights just to see how it works for you. I generally like neutral to slightly warm but one example of where I found ugly blue cold white helpful was with thermal paper reciepts where the ink had faded considerably (pretty sure they were thermal…) and that “ugly” light gave better contrast for me. It’s interesting to play around with temps and see how it affects perception, and when you’re dealing with somewhat shiny metals of different colors it can make quite the difference.
One thing to point out, maybe more so with the 4000-5500 temp range is that the tint can make all the difference, and that can be exacerbated when running the light at low modes/low currents. This is where a high CRI with good tint really…shines. The color rendition may not be important to you but the (usually) better tint make it much more enjoyable and often more helpful. I would take a good crisp 5500 or 6000 with a neutral tint (close to the BBL) over my favorite 4500-5000 with a poor greenish tint (well above the BBL).
On those placards, sometimes a spritz with water or a wipe of spit will help them show up better, too, or a wipe with an oily rag (even if they aren’t dusty or oxidized).
I used a 4 Sevens Mini for reading labels on servers and other IT type equipment in a data center. Actually I had two or three of them. IIRC one type was ~6000 K and one maybe 4000 to 4500K. I never really found one better than the other.
I di find that I usually had to use the lowest level, get the light close, and adjust the angle for the best contrast. Using medium or high just seemed to wash thing out.
I think that CRI in this case is not that important. Most of the labels were silver on black or white on black. Some just embossed. Not really any color there to render.
Maybe cans with different colors for warnings etc. might make CRI more important, but I really don’t have any direct experience there. With a can, I am able to take it to a place with decent light (daylight preferred) to read it.
For reading books, I prefer ~2400K and lower levels. Easier on my old eyes
Yeah, I spend most of the day looking at either a monitor or a TV or a laptop screen.
I have no idea what the PWM is of those screens because I don’t notice PWM, but I luckily don’t experience any headaches or anything negative from looking at screens all day long (that I am aware of.)
Backlight may use PWM when below certain brightness (or always), but then it is a matter of choosing a monitor which does not do this, just like with flashlights.
In “at work” environment PWM light may have additional downside - cameras are everywhere nowadays and often causing flicker there is really bad.
I totally believe you. I myself don’t really see the flicker, but that doesn’t mean it can’t have any effect. After extended time after the screen your eyes may feel tired using lesser screens. But 7 billion people, 7 billion ways to experience the same thing.
I have an Amazon kindle e-paper reader. Everyone I personally know says it’s easy on the eyes, but why can’t be defined. Sure techinicallities can be listed, but the eye doesn’t really see them, but does experience them.
Maybe that’s also what’s going on when trying to read in bad conditions.
Eyes most likely have a ideal brightness, contrast, temperature etc for reading. But (especially young) eyes are able to adapt.
It’s like during the day, daylight seems fairly constant in brightness because your eyes adapt.
My point is this, if we try to see/read on the edge of what our eyes are cable of, they may benefit more from 1% better color temp than from 5% extra brightness. Just an example that may be totally wrong. That’s why I started this thread.
I have to assume that you do not have a 3000k high cri light or you would not be asking this question. Correct me if my assumption is wrong. And depending on how dark it is where you are reading, yes you do want to be able to go down to single digit lumens. I’m not saying that 4000k can’t work fine. But there is no way that anything 5000 or above is going to be “best” for the majority of cases.
Your assumption is entirely correct.
My plan certainly is 5000 or below.
Also looked at 4000.
3000 might be a bit scary for 6500k guy…
In my experience both high CRI and very low K are not so easy to find. Especially the two combined.
Likely because many companies are in the pocket rocket competion and they tend to be low CRI, high temp.
You might be a good candidate for a tint ramping light from Hank. You can pick your emitters for each channel (four emitters, two each). I think all said and done you’ll be in the $70 range but he has the 18650 D4V2 and KR4 (tail switch), and the 21700 D4K (all are quite compact and very close in size to one another)…lots of customization options. A popular choice is the 519A emitters in 5700K and 2700K which gives you a full range and they are high CRI with excellent tints, UI is easy to operate as well (both the general Anduril and the channel switching features). The non-tint-ramping models are just a little cheaper but it sounds like this would be both practical and educational for you and the quality is excellent especially for the price point.
