519a, 219b, 219c, LH351D, or E21a to shine on artwork at night?

Hi there - check picture below, shot in RAW with fixed WB 5000k. The background blind is off-white - you could look at this to see the different tints of the various LED’s. The hat is USC red - very difficult to reproduce accurately (this is the CRI “R9” spec).

My vote is CCT 4500k (4000k too warm/yellow and 5000k too cold/blue, YMMV) and LED is 219b 4500k. Long considered among the very best both subjectively (among other things, makes colors pop) and objectively (among highest Ra and R9 of all LED’s). 219b nails the hat’s red color here. You could check comparison pictures, MHO’s, and specs of many Nichia LED’s in that same thread I listed below.

Among other LED’s you listed, 519a is next best choice. Note it has a yellow/golden tone; lovely and soothing and among my most favorite, but that yellow tone is hard to overlook once you know it’s there. My 519a 4500k measures 4000k and looks too yellow for my taste but subjective opinion means YMMV. More 219b and 519a comparison here (see how palm tree and hot pink flowers “pop” with 219b): Convoy S21D w/ legendary Nichia 219b :) - Review & comparison w/ Nichia 519a, E21a & other LEDs & lights (D4V2, Convoy S21F). - #4 by cannga .

I have specifically taken all my best tints and pointed them at rich & colorful paintings. The high R9 is the way to go. And if you don’t mind a little warm, then that is extra nice on paintings. It gives them an added pop and tons more depth. So you are definitely scratching in the right area.

I have found that the purest and cleanest tints with the least overcast color tones is the E21A. The 4500k & 5000k alone will give you really great and crisp R9 (reds). But if you added about 25-30% of the 2000k, it gets all the extra color pop. It does get warmer, but also richer. And that why it feels like it’s worth it.

The 3800k Mix Fireflylite is VEEEERY nice.

The first shot is the Costco lighting, second is the PL09mu 3800k mix. So as you can see, it gives things quite the boost. Slightly warm yes, but in a pleasant and easing way.

Another great option would be a 219B tint mix. Like a SW30/SW45k, or if you want to stay closer to 4000k, do SW35/SW45k. But again, E21A (Mixes) are gonna end up being the purest while still adding as much tint and color as possible at any CCT.

Ultimately, the best tints I have ever seen, are the E21A mixes. So those are easily the ones that I’d be confident saying would do the best job for this. I can’t recall, and maybe I’m making it up because I want it to be true. But I think I remember hearing that the E21A was made specifically with museum & art gallery displays in mind. Could be wrong tho. Either way, I can tell you that the most absolutely stunning tints come from mixing E21A’s. I hope you enjoy whatever you end up choosing.

Great comparison there cannga, I may have to pick up one of those gt-fc40 emitters they look great! Another one to consider might be the b35am, its essentially four e21a emitters in one package. Its 6V so you could use an efficient boost driver which should last longer at lower currents. The downside is the unusual footprint but convoy sells them with MCPCBs

Museums and art galleries around the world have experimented a lot more than that one guy. Stick with 3000k or less. The beam pattern on many 90° lights is going to vary. So you can’t assume a different light from the same distance is going to light up the same size area on the wall. The convoy h2 @3000 is a reasonable choice to experiment with. I believe you have a choice of two different beam width patterns on the H2. At that close distance you’re going to want the widest pattern available. Some other lights go wider but there are not too many available at 3000k and the ability to charge without removing the battery. Armytek Wizard C2 Pro Nichia Magnet USB Warm - 3000k — Killzone Flashlights

A normal tungsten 2700K, or halogen 3200K incandescent bulbs have excellent color rendering. About 3000K is nice at night.

Up to you how to install it. You might consider a floor lamp, that bounces off the ceiling.

IF you want LED
I suggest you buy this 3000K Photo Grade LED bulb:

definite NO to any LH351d due to low Red Spectrum output

IF I wanted a 3000K flashlight LED, I would choose the 219b

3000K 519a is yellow/greener, also true for E21a and 219c

Ideally we want Optisolis™ Lighting | NICHIA CORPORATION some of the Nichia optisolis leds, designed specifically for museum lighting. COB version for a mule would be amazing.

I remember reading 5000K being great for art works, since its neutral white. Was that a wrong info?

I think this is almost completely subjective. I personally don't like the super warm lighting I find in art galleries, which makes colors look imbalanced. I would prefer the 4000-5000K range for general use.

Same goes with level of rosy/magenta. If the painting features lots of colors involving greens and browns, 219B and E21A tint mix are so pink that they will make these colors look off. I'd stick with something completely neutral in tint.

I said Nichia possibly designed the E21A with displaying art specifically in mind

But I can see how me saying that is the same as me automatically INSISTING that since the beginning of time…every single museum and art gallery around the world has only EVER experimented with the Nichia E21A and nothing else. :+1:

Ok, back to those that take the time to actually read and think things through before opening their mouth…

It turns out that the Nichia LED I had read about that was designed for displaying art was the Optisolis (Thanks Clientequator).

Either way, E21A would be great if that one is not available, it would just depend how warm you are willing to go. A 4000k E21A mix would be amazing, but you could gain and lose a few things depending on how much warmer you decide you’d be willing to go.

Jon mentioned 219B SW30, that is an amazing choice if you don’t mind the warmer hue’s. But it really does depend on what your specific painting looks like. If it’s red-rich, maybe a rosy mix will best accentuate it. If it’s more of a woodsy photo, something a bit more neutral could be ideal. It just depends on how you want the painting to be experienced too. Do you want it cozy and colorful, or bright and vibrant. Decisions decisions.

I’m carefully reading through your responses. I don’t find my exact painting on the internet, but it looks a lot like the 4th one down in the long list of paintings in this link: Mine is dominated by blues and oranges, with a fair amount of olive an other green from trees.

https://www.risunoc.com/2020/08/yarkie-i-smelye-czveta-didier-chretien.html

He applies very thick paint with a pallet knife. The 3rd from last painting shows the texture of his pallet knife application.

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.canada.ca/en/conservation-institute/services/conservation-preservation-publications/technical-bulletins/led-lighting-museums.html&ved=2ahUKEwjc_Pi868f8AhX0pokEHYBWDtwQFnoECAwQAQ&usg=AOvVaw1fry2Q50U-gFx3MzP6FQgH There’s no single answer. For various reasons 3000 –3500k is standard issue. Do your own Google search for “museum color temperature”. There is a lot of information and research out there.

The LED really depends on the exact Bin you get, which is hard to determine before buying (or reading other’s experience with exact LED from that vendor… and then there is still the tint lottery).

With that said, I’ve spent some time sampling different vendors LEDs and buying the best hi CRI I could find. Best = neutral to slight negative duv.

219b, 519A and SST-20 have the highest CRI and all can be found with neutral to slightly negative duv. (I haven’t tried E21A LEDs)

- 219b can be too negative. It depends on the bin, but generally pretty close to neutral if you avoid the 45k variety.

- SST-20 is hard to find in neutral or negative duv at low currents.

  • 519A I’ve tried have all been neutral duv (from Clemence).

I would buy an Emisar dual channel DW4 with 519A LEDs. Pick the lowest CCT you might like for ch:1 and the highest you are considering for ch:2.
This will give you neutral duv, high CRI, and variable CCT. The duv will get neg more negative toward the center of the mix, so don’t pick CCTs further apart than you anticipate wanting. I would do 3000k on the low end and 5000k on the high end, except I don’t see a 5000k option. So you will have to select 5700k or 4500k depending on your preference.

This option is more money, but is an excellent light and gives you the most flexibility.

FB

OT: I don’t have every LED, but of the ones I have, Getian is the only LED that comes close to Nichia with respect to great color rendering. What’s better it has higher output (2200 lm) and higher throw (300 m) than most similar-size Nichia lights.

My B35AM 4500k is in M21F host - highest CRI and R9 I’ve ever seen, but in this host it is throwy and though I love/cherish the light, the rosy tint is not as well appreciated as in the floody beam of S21D 219b for example. I prefer Nichia goodness in floody beams.

Re. E21a that OP asked about: very similar to 219b color rendering (this and B35AM are closer to 219b’s rosy tint than any other LED I have), except it has a yellow tint shift; IMHO I would pass. I did photo comparison here: Convoy S21D w/ legendary Nichia 219b :) - Review & comparison w/ Nichia 519a, E21a & other lights with Nichia LEDs incl. Emisar D4V2, Convoy S21F. (Summary & measurements on P. 1) - #17 by cannga
Hope this helps.

There’s a lot of information out there about museum color temperature. For those that prefer 4500k flashlights, that’s all well fine and good. How and where you use them matters. It takes your eyes a while to adjust to different color temperatures especially going from 4000 down to 3000. So quick and dirty experiments are always going to favor higher temperatures. Background lighting and what you were exposed to over the last hour also influence this. If you walk into a museum and all of the lights are between 3000 and 3500, after a little while in there you’re going to be fine with it. Most all of the lighting in my house is below 3500. It may actually be all below 3,000. I’ll have to check everything again with the Opple.

so, I have an idea based on a couple of posts.

i could order the mixed LED from Emisar DW4, or the mixed E21a from Fireflylite,

or

I could simply buy two H2 lights, one in 519a 4500k, and one in 519 3000K, and mount them both next to each other. Then, using the ramping, have one at 20lm, the other at 30lm, or whatever combination makes the painting look best, non? Or I could do the same with 219b at two temperatures. or, I could have one 519a at 4500k and one 219b at 3500.

Gosh, the combinations are almost endless, factoring in ramping.

For what it’s worth, my initial thought was Nichia Optisolis LEDs. I have built 3 triple flashlights using these LEDs and they are impressive.

The reason why I thought about these LEDs is that this stated on the Eurekatronix website:

Application examples:

  • Museum and art gallery

I was reading the link that clientequator posted. One of the reasons the Nichia Optisolis LEDs are highly regarded for Museums and Art Galleries is because in addition to the high CRI, it also says that UV emissions from the LED is non existent so it minimizes UV degradation of irradiated objects. Something to take into consideration.

White LEDs don't emit any UV at all. The thing that distinguishes the Optisolis is that there is violet in its spectrum, which generic high CRI emitters lack. The cyan dip is also virtually nonexistent.

I have a quick battery question related to this project… what battery is appropriate to the Convoy H1 lamp? I am looking at 18650 battery dot com. I see 18650 protected vs. not. 2000 to 3500 mAh. Some specify voltage, others do not… and the big question, what number of amps does the H1 need, as I will be running it at about 1% of max power for about 5 hours a nite for about 7 days, then will need to recharge them?

It seems if I don’t need 15 or 25 amps, 3500 mAh cells at 10amps or slightly below are about $6 or $7 vs. $10-$13 for protected and/or high amperage.

For example, this one: Sanyo NCR18650GA 3500mAh 10A Battery - 18650 Battery Store

The battery that you linked is good. The H1 maxes out at 3 amps, so I would pick a high capacity battery vs high amps. And it has low voltage protection so a protected battery really isn’t needed. It appears that a protected battery will fit in the H1, so it’s up to you if you want the added safety.