Super interesting. You may or may not know this, and this may or may not be "fact" but... I've done a ton of offshore sailing - and we take adjusting to darkness seriously enough that we only use red lights at night (otherwise you come up on deck and can't see that ship on the horizon at night). Well rumor has it that the pirate eye-patch was actually used to keep one eye adjusted to darkness so that when you were fighting, and went below deck to murder everyone you could just move the patch to the other eye and you were all set with night-vision This of course is impossible to confirm, has problems with combat like depth perception - but, it's a fun theory.

Thanks Mark Always a pleasure to watch your watch and learn vids with in depth information. Looking forward to your next one

Radium paint had zinc sulfide that was excited by the alpha particles from the radium and emitted light. Eventually the constant bombardment burned out the zinc sulfide and the dial no longer glowed. I have two old pocket watches with radium dials and they definitely excite a Geiger counter, since they’re almost as radioactive as the day the dials were painted.

What a useful and informative video, Mark! After new watch collectors get over the initial excitement of learning about brands and watch types, this is exactly the sort of technical information that becomes so fascinating. I'm going to have to check out other videos in your watch and learn series.

I am a big fan of Tritium. Back when I was working night shifts, I didn't need light sources to recharge my tritium dial.

Excellent video. Thanks for taking the time to film and edit it and of course for positing it for our benefit. I would have liked to see examples of all the bright dials. Keep up the good work! -Migs

Excellent video as usual. For everyday use, regular lume is more practical. During my day I often go into almost total darkness from a sunny daylight and that means my eyes are not adjusted but thanks to the incredible initial brightness of regular lume, I have no problem seeing the time. Also in the case of Seiko I have yet to wake up anytime in the night and not be able to see the time, as it is more than enough for adjusted eyes. Tritium on the other hand, although will look brighter to my adjusted eyes in the middle of the night, in my daily activities it is invisible when I enter a darkened room from the outside. After some time my eyes do pick it up, but I was eventually dissapointed, or should I say, regular lume suits my way of using watches more.

After buying a couple tritium watches from you a few months ago, I will never be without one again. I far prefer it to the typical lume, especially when I wake up in the middle of the night.

Definitely enjoyed the video Marc. Your knowledge and clear and simple deliver of information is excellent, which makes watching and learning from your videos both entertaining and educational me. Thank you 🙏🏻🙂

Fantastic! I think that's the best explanation of watch lume I've seen. Plus the direct time lapse comparison is very....uh......illuminating. good stuff - keep em coming.

I just bought a Marathon TSAR from your site Mark. Tritium watches are my favorite. My TSAR is the 3rd tritium watch in my collection. Love this series

This was so detailed and thorough. Great content ❤️

Best watch channel on KZfaq

You are great ! You know so much, I enjoy your talks and have learned a lot through them. Thank you.

congratulations, your videos are always really informative and interesting.

Purchased a SKX013 from Long Island Watch this week and was very pleased to run across this informative video on how it's lumination works. Thanks for sharing. Really enjoy watching all your videos. Keep up the good work.

Thanks again Mark, your effort is much appreciated.

Love your vids Marc! So informative! Thanks for all you do. Loving that my Long Island Ray is on the way!!!!!

Thanks for making this video. I have never had a clear understanding of the mechanisms involved with glo-in-the-dark watches. I have older watches that seemed to have lost their ability to absorb and re-emit light anymore and was curious to whether or not they can be rejuvenated.

Great video! I have a Seiko World Time from July of 1973, and I was surprised to see the lume still worked! If I had watched this video first, I wouldn't have been so surprised! Thanks for making this video! I really enjoyed it!

Great video! Really informative, good job with explaining it so throughly.

Great video, Mark! Thanks!

This is the most concise video on the topic of luminescence regarding in particular wristwatches I've ever come across! . . . Thanks for sharing!

Hi Mark ! Thank you for this new video 👍 Very interesting the way you explain us the story of the lumi in time history, really appreciate 😉 Keep blowîng our minds with your great videos. Thank you mate 😉

Excellent video, Marc. So much knowledge to absorb from these videos. Thank you.

This was really impressive mark. Thank you for the education. Cheers

Love this series. I get to look at watches... and learn... (hence the title) awesome! Thanx Mark!

Great content! Very informative

THIS is the best way anybody has EVER explained ANYTHING ever ! You are awesome sir Thank you ❤️

you did a terrific job on this video… I was curious and the way you explain it all was fantastic. So thumbs up and thank you so much for sharing the information so wonderfully. Good job

Excellent as always Mark. I've been that guy "hey, why is this tritium watch broken?" You live and you learn. Now my little radioactive buddy is a constant star amongs all the napping lume watches in the box :)

Incredible amount of knowledge! Thanks

Fascinating - Great video! Thanks, Mark

All of your vídeos are awesome, I just can't stop watching them, they are very addictive :)

Great info, really appreciate it!

Really informative. Excellent thankyou!

Since I got my marathon gsar I'm hooked on tritium vials. I started to keep the watch on when sleeping so when I wake up during night I can see that fantastic lum and see the hours and since the watch is very comfortable I don't feel it with a nice leather band. It is by far the best lum but the vials take some space so it make the watch thicker but I don't mind it at all. That marathon became my favourite watch almost instantly and it's my most accurate mechanical at +2 +3 /d constant even when keeping it on while sleeping. Fantastic watch worth every penny.

Great tutorial, thanks!

Great job as usual.

Another great video! Cheers Marc!

As always a great video. Keep up the good work

Very informative. Thanks Mark!

Another great video, thanks Mark.

Nice informative video. Never skipped a second and watch it all. Thanks for sharing.

Really cool video. Thanks Mark.

Another fabulous video ! Thanks again !

Cool History. Thank you for the education.

Nutnfancy directed me to your channel. Loved this video.

Excellent explanation of watch luminosity. I bought a Luminox not too long before purchasing a Seiko Automatic from Marc's Long Island Watch (EXCELLENT service and am extremely happy) and was wondering about how the different luminosity worked between the two. Thanks Marc... again.

Great vid. Great channel. 👍

Very knowledgeable. Great lesson.

Thank you, this was informative & consolidated all of the info I was struggling to find the answers to on several websites. Such a nice break from pretentious watch KZfaq.

Good and informative series I recommend to my friends that just start out.

That was a superb, fantastic and excellent "quick" explanation of watch luminosity. I am a newbie to wearing a better quality watch, after watching your video I immediately subscribed. Thank you for taking the time to help teach people (like me) who are new to higher quality watches and want to understand their components.

Great video, as always. Thanks for that. Btw, as a lume aficionado I bought me an UV light flashlight from Olight. It needs a second to blast my watches into full lume power. Beats the snot outta normal artificial lights, no matter how strong would they be. After all, it's UV in sun light that's the best way to go. I prefer lume over tritium. The later is not bright enough for me.

Good content, I had my finger on the trigger to click away from here when I saw a watch on each wrist but I'm glad I got distracted and stayed.

Very educational...thanks Marc!

My Seiko glows through the whole night. Pretty good stuff! Thank you for your videos.

Great video. I learned a lot.

Man, would love to have a Sinn (or a Doxa) - great watches. Great presentation again, Marc. Thank you. Ever read the book about the Radium Women? A sad read about those that painted watches and got cancer and were neglected by the companies that knew the dangers.

best explainer video on lume ever

Big Fan, very informative

If I had known about the differences, I would have bought a Tritium watch. I need to see my watch in the middle of the night. I didn’t do enough research. Definitely need to get one that suits your needs. Maybe someone will make a watch with both. That would be ideal. Love your vids Marc.

Great video

Excellent!

Great video! This is the stuff that is interesting to me. Other videos I've watched, they take everything apart and put back together so fast I can't keep up. And they rattle off the names of every piece of the movement so fast. This is my speed. I have a couple of old mechanical watches that I thought I might tinker with for fun, but I'm sure I'd get the parts mixed up and not know where they go.

Great show Marc, hreat narrative. Thank you.

Excellent video. Thank you.

Very interesting video, ty!

This channel rocks.

Nicely done. Thank you.

Wow great explanation. I'm so happy I found your channel. Thanks. And when I need a new piece I'll give you my business. :)

Watching this with a UV LED charging my Seiko and Citizen lume. Awesome, and I also have an Android Skyguardian withT-25 tritium tubes and it's my fave for going to the movies.

THANK YOU!

Perfect wrist checks. I currently have a Sarb033 and Sinn 104 in my collection.

Marc, another great video! You explained the differences and what was happening with the tritium very well. Knowing what I know, thank God tritium is regulated as much as it is. I don’t want to get into it on an open form such as this. Anyway, great video.

Fab vid! I rather like your U1, too.

Very informative

thank you for this video

I have an old seiko which doesn't really shine anymore ,but when i put my phone flashlight on it for some time it works for an hour or so Is there any way to fix it ? Thanks

Very informative. I have a Ball Ducks Unlimited that has the tubes and it is awesome.

Great video, thank you. I want to get a NITE and now will get the T100 version.

Wow! Back to physics class. Very interesting, thanks Mark.

Coming to this over two years later, but as timely and thorough as ever, so thank you. You may never see this, but my questions are, when did he photoluminescence become a thing? I could swear that I had a glow-in-the-dark watch as a kid in the 70s that you had to charge, which fascinated me. And how did they get hydrogen gas to stay in a paint?

Great video, I'd to see a comparison between T25 & T100.

Modern watch lume (i.e. the type not based on radioactive decay); better called phosphorescence, is the delayed release of light energy, re-radiated at a longer wavelength after 'pumping' by incident electromagnetic radiation of a higher energy (shorter wavelength); technically: inter-system crossing from a singlet excited state to a triplet ground state; a dual electronic and vibrational transition. Long time since my undergrad chemistry days but hey, I remembered something! ;) Couldn't resist; sorry, but thank you for a very informative and excellent presentation!

Very cool 😎

I switched from seiko divers to the upper end divers from Luminox because of the Tritium. So much better and I am amazed how durable and precise this Luminox is.

Very informative feature ! I bought a Traser Officer Pro Gun Metal Lime based on one of your previous features.

My Omega PO still visible at 3 am after a normal day usage. I’m very impressed.

Thanks! Any added information if any company or watchmaker can apply tritium tubes as a re-service or as a stand alone mod? Maybe you can do a service like that in the future for your company.

Great info. Thanks. Question, do you have any idea what the ‘original’ color was of tritium hour markers/indices? Was the tritium white or tan/yellow/cream color?

I really like your channel. I don't think we have similar taste in watches at all but your videos are great nonetheless.

On the subject of our eyes being most sensitive to green light at low levels, green OLED sub-pixels are also the most power efficient of the red, green and blue sub-pixels which make up an OLED pixel (perhaps partly due to our eyes sensitivity). I set my Apple Watch 5 to a minimalist display in green, disabled the always ON display functionality and disabled all the apps I don't use and in doing so went from around 18 hour battery life, to 4-5 days.

Great video Mark, thanks. Have I understood things correctly that photo luminescence never wears out?

Are you an engineer or a watchmaker? You are giving us a lot of great information. I really like the watches you review and the watch and learn. My buddies think I’m a watch genius.

I grew up in the era when all watches had tritium or radium. All the men had age spots on their wrist from where they wore their watches. Now I'm older and I got the same age spots around thirty years of age( I'm much older now!). When I was a kid I used to wonder why my old watch glowed all night and my new one didn't. It was so bright and the color was fascinating, I wonder how bad my retina is burned.

Its like in school but fun. Thanks Mark!

I played Dr. von Sochocky in a production of the play 'Radium Girls'. I researched it and found out more about the story. It was very tragic.

Awesome...!!!