How to Eclipse When All You Have is a Welding Helmet

What do you do if you don’t trust cheap eclipse-watching glasses from the internet? What about if everyone’s sold out? Well, if you want to watch the eclipse and you have an auto-darkening welding helmet, you can do what [daniel_reetz] did and hack something together with a remote and your welding helmet to let you see the eclipse without blinding yourself.

Essentially, the hack tricks the helmet’s sensors into thinking it’s very bright. [Daniel_reetz] accomplishes this by gluing a remote with an infrared LED to the side of the helmet and covering it with a 50mm plastic lid. There are two sensors on [daniel_reetz]’s helmet, so he covers the other one with aluminum tape. What this means is that when he presses a button on the remote, the lid-covered sensor thinks it’s very bright out and since the other sensor is covered, it darkens the lens of the mask.

I’m sure some of our readers could come up with a more sophisticated method that would allow you to do something other with your hand than press the remote buttons, but this is a quick and easy hack that’ll get you able to take a quick look at the eclipse – assuming you have a welding mask capable of shading to level 13 or 14. If you are hoping to catch a glimpse of the eclipse, check out the safety guide from NASA just to make sure your eyes are safe. For another method of viewing the eclipse, check out this wearable pinhole camera. For another welding mask hack, check out this augmented reality mask.

84 thoughts on “How to Eclipse When All You Have is a Welding Helmet

        1. While not technically a real term, “Auto blackout thing” does describe my welding helmet quite well. So I think you might be the one that needs to stop insulting people over stupid things.

    1. Contra to what the description on HaD says, these auto-darkening helmets look for modulated infrared light. If I had just covered the sensor it would receive no infrared light at all, modulated or unmodulated so I’m not sure what you mean. In the embedded video I did show that it doesn’t trigger by looking at the sun directly.

      If you go look up the patents on auto darkening welding lenses, they include some interesting schematics. They basically have a photodiode or phototransistor to pick up the modulated light, a bandpass filter in the 10-200Hz range, and a comparator circuit after that. If the arc detection circuit sees activity in the bandpass range, the lens triggers.

      Some more sophisticated weld helmets have a sensitivity adjustment that goes so low that you can trip the comparator just by setting it to very high sensitivity. None of my helmets have that, so I used the remote control.

          1. Ditto mine. It will trigger just from the sunlight coming in through the open garage door, don’t even have to be pointing directly at the sun.

            I should mention that even though mine auto darkens from the sun alone, I won’t be using it to view the eclipse, and don’t recommend it to anyone else – I’m too paranoid to use anything but a pinhole lens/box projector to view the eclipse – I think that’s pretty much risk free…I’ll be facing 180 degrees away from the sun with one of these.

          2. Mine, too, darkens when pointed at the sun. Or, depending on sensitivity, even just a reflection. Actually, if the sensitivity is turned all the way up, it’ll trigger when just getting it near a lightbulb.

            I’m no expert, but I think the ones that trigger on certain frequencies are falling out of favor. Since good (or even mediocre) DC inverter machines produce little ripple on their outputs, that technique (which is only a convenience to prevent it darkening from normal light sources) has/is falling out of favor.

            For reference, mine is an older version of the Antra AH6. Got it because it’s apparently reputable for being an actually decent helmet, despite being dirt cheap. Can confirm; it doesn’t feel especially durable and the friction mechanism isn’t super great, but it definitely lives up to that reputation.

        1. I have a couple different auto darkening masks here and they are triggered by the sun as well. I’m just wondering – will they “let go” when things go dark because the eclipse is happening? I’m pretty sure they will. I don’t want them opening up and letting all that light in when the eclipse is in full swing.

          1. The good news is that they afford full UV and IR protection even when the shutter is “off”. But why not just tape some remote controls on, or bring some with you, to be sure that you can actually do this? Belt and suspenders, they say.

      1. I have an Optrel p550, I haven’t tried it with the sun yet but it does have a sensitivity adjustment and at the lower settings it will trigger from just a lightbulb.

      2. Thank you for the idea it works my husband used remote from stereo and electrical tape and taped remote over the top of first sensor and electrical taped other sensor pressed button and it works..thank u for the idea.

      3. When i was a child, i prepared for an eclipse by trying to use the soldering helmet glass, but since in my coutry we didn’t had the 30 ones, i bought 3 of 11, but sadly, it was cloudy, but i’m curious, do you think that could have worked ?

    2. Not true.. turn your sensor up and the instant you look into sky (without looking into eclipse) auto darkens the lens… so the lens should already be dark (shade 13 at minimum) before you look at eclipse

    3. I don’t think his helmet has the sensitivity to fire up quick enough. Mine goes up to 13 tint, and has a sensitivity dial. Dialed all the way up. lights in my house cause it to tint, and on 13 I can’t even see the lights. I just took it outside to test it, and it worked fine. At 13 I couldn’t barely even see the sun as it is right now, so I’d assume I’ll be able to see it fine with the eclipse going. If you’re worried about tint delay, hold your helmet in the direction of the sun for a second, then put your head in it like that. By that time, tint should be triggered, and you should be fine. Guess we’ll find out anyways. Either that, or I’ll be blind today. lol jk I’ll be out in my shorts, cowboy boots, and welding hood. haha 35 years old, and I ain’t never seen an eclipse.

    1. Is there actually some reasonable risk of becoming blind this way?

      The usual way to get vision damage when looking at the sun is to have a filter that only blocks visible light, while letting the damaging UV through. But a welding helmet is not likely to be defective in that way, and even if the remote fails, you’ll notice immediately that it’s not dark anymore.

      1. You can stare at the sun without any problem. The eye’s iris will close restricting the amount of light reaching your retina just fine. Just don’t stare at it too long or permanent damage may occur.

        HOWEVER. That’s not what’s going to damage your eyes.

        When the moon completes its transition your eyes won’t adjust quickly enough – your iris will be full open because it’s dark – almost night-time, then suddenly it’s full daylight. Oops, there goes your retinas.

        It’s like the temporary blindness you get with flash guns or super bright torches. Except the sun is a bit brighter.

        Reasonable risk of becoming blind? I’m not an Ophthalmologist. It’s almost a certainty that your retinas will be damaged permanently, as for becoming blind – I just don’t know. I guess there’ll be news of the less informed that will have done this though.

        1. Everything I’ve read has said you can’t go completely blind, but you can become legally blind. And it can’t be corrected/fixed. You have to hope it fixes itself, which can take months, or a year. Some never heal.

          It’s two forms of damage:
          1. Photothermal: Less UV and more IR, which is what’s causing most of the burning that can happen. This fries the back of the eye that controls sharp image control (retina>macula>fovea), which happens without even causing pain. This is why you’ll still be able to see, but only fuzzy colors.
          2. But my understanding is the greatest damage is actually photochemical, which I can only find to be theorized. It’s basically what’s constantly killing us from birth: oxidative stress leading to free radicals. But here it’s happening because a ton of light hits a ton of photoactive material and the resulting free radicals cause a chain reaction that rips apart molecules, damaging and destroying cells. This reaction can only be stopped by antioxidants in your body, so I’d assume it’d be different for each person. But that’s not something I’d personally want to test.

          I can’t speak on iris dilation as I’ve not read anything on that, nor would I expect any expert to want to theorize it for fear someone would do it. Damage is going to be based entirely upon the situation, the individual and how quickly the photothermal and photochemical damage occurs/stops.

      2. No, there isn’t, or the risk is very slight.

        One of the great things about the auto darkening lenses is that the UV and IR protection are dichroic and metallic coatings on the lens – even if the lens doesn’t darken, you will still be protected from ultraviolet and infrared radiation. However the visible component is still very intense and will certainly make you uncomfortable after a few seconds.

        The HaD crew is certainly sophisticated enough to use an Arduino or a 555 or something to generate an IR signalo to continuously trigger the helmet. Heck, people here could easily build the dual supply AC driver that these sorts of Pi Cell liquid crystals require, and they could just drive the shutter directly. I know I could, I’m just not interested in going that far, and remotes are a lot more accessible to the average person. Plus, I want my helmet back after the eclipse.

    2. FYI, the arc from the two most common welding techniques, MIG and TIG, are 10x and 20x brighter than the Sun respectively.

      A good (and by good I mean something other than Horrible Freight) shade 13 welding helmet is plenty sufficient.

      My Miller Digital Elite is actually a little too dark on full shade.

    1. That’s what I was wondering about. My dad only has helmets that are dark all the time – call him old school, he’s in his 70s, everything about him is old. But his are rated 9 and 10, and the weather channel website said, if you want to use welding goggles or a helmet, it has to be rated at least 12. It seems that most passive lens helmets are about a 10. So I was wondering, can you wear sunglasses under the welding helmet? I’m not a welder, I just don’t want to miss out on a once in a lifetime phenomenon, and watching on tv seems kinda lame when you can do it for real. But I also can’t afford to pay for glasses that are only going to be worn one time.

      1. Most sunglasses from what I’ve seen, would be a bad idea.

        The reason being that what they do is selective in the spectrum. So it won’t block all of the broadband light, what it will do is cause your pupil to dilate. UV and IR damage isn’t always apparent, and one of the things they contributes to is cataracts. Which may be something that isn’t apparent for a while. (Your lens will absorb most near UV, though you could see it otherwise, which is one of the causes.) IR’s path to damage and some things like cataracts appears more convoluted, but it seems that there’s a consensus that it does cause damage. There’s not a ton of case studies it seems. (So if you do damage your eyes make sure you have the exact things you were wearing, so that you can be written up as a case study in a medical journal.)

        1. Wearing solar filter glasses will also cause your pupils to dilate, as welding helmet will. I know when I flip mine up I have to adjust to the room brightness, which is why some weld shops, or areas were one is welding, are a not as bright as say a wood shop or machine shop.

          A proper welding lens though, will filter out the harmful UV and IR that is caused by the arc. So, sunglasses might provide the extra bit of shade required.

      2. Apparently, you can add shade numbers .. sort of. Here is a thread with a lengthy discussion on the topic. One post stood out in particular:


        If you convert the shade number (S) into something called “optical density’
        (OD), then the OD numbers do add up when you combine them. the formula is:

        OD = 0.428 * (S -1)

        To convert back from OD to shade # the formula is:

        S = 2.33*OD +1

        So a shade number of 7 has an OD of 2.568 . Two of these used together have
        an OD of 5.136 which is a shade number of 12.96 An OD of 5 or more is
        usually considered safe enough for sun viewing.

        I have no idea why the welders shade scale was made different than optical
        density.

  1. “assuming you have a welding mask capable of shading to level 13 or 14. If you are hoping to catch a glimpse of the eclipse”

    Per NASA’s page, the minimum safe Shade Level is 12 – I happen to be borrowing a couple of shade 12 welding glass from a friend who had them from the Venus transition a few years ago.

    1. I have read that shade 13 is preferred because “most people” find shade 12 to be uncomfortably bright, even though it’s attenuated enough for safety.

      I dunno what’s wrong with “most people”, but I got a #12 lens to swap into torch goggles, because I wasn’t happy with how incredibly dark my fold-up eclipse glasses were, and I don’t find it uncomfortable at all — with normal iris contraction it’s just fine.

  2. My Miller Autodarkening welding Helmut is fail safe, meaning that I can just take out the battery. Might want to try this on your brand..

    or better yet… Spend a little more money protecting your eyeballs. Could be argued that they are the most important tools that you own, right next to your hands.

      1. What’s the model number? Neither my Miller or Radnor hoods are fail safe – or at least they don’t go dark when you lose power.

        All these lenses implement the UV and IR blocking via metallic and dichroic filters, so in that sense they are “always on”. Doesn’t help you in the visible spectrum.

  3. I can remember using two CDs (double thickness) to protect my eyes when looking at sun during the total eclipse of 1999 in the UK. I wasn’t in the path of the total-eclipse, but IIRC this still seemed OK at filtering the sun to a comfortable level. Dunno about UV light though.
    I also remember that cardboard eclipse viewing “glasses” were cheap and readily available so probably best to seek those out, (even just as a plan-B, so you don’t miss anything.)

    1. Lowes is selling eclipse glasses from American Paper Optics (which is an AAS, American Astrological Society, approved source among several others – for proper ISO certification).

      They are selling them for $1.98….much less than a the cost of a Welding helmet or anything else for that matter.

    2. I just broke out my old school shield from then also, I passed it around in a parking lot so all could see. I didn’t go blind using it and it takes a while for this to occur it is not instant.

  4. Should my helmet flicker constantly when applying this trick? For example, when I hit the infrared button, it releases discontinuous light (just like in your video). Thus, when I hold a bright light underneath to check the functionality of the shade 13, there is a faint flicker of that light. It doesn’t appear bright, but I worry the discontinuity of the ifrared light is causing the shade filter to flicker so fast that it’s difficult to tell with my naked eye(s). This seems like it could let light in that is dangerous. My model is also a Chicago electric from harbor freight.

    1. I saw this same behavior when the solar cell was accidentally covered up. Be sure your solar cell is exposed and maybe try it outside to make sure the cell is illuminated.

      These auto-darkening lenses are designed in such a way that they offer the same UV and IR protection in both the on and off state. So, by just looking through an “open” lens, you are already affording yourself good protection from the most dangerous forms of light.

      However, the lens needs to be dark give you full protection. As I mentioned, be sure your solar cell is exposed and gets a little light and things should work out just fine. Someone in the Instructables comments reported the same thing as you. In the YouTube comments, someone reported that Sony remotes work best. It’s worth trying another remote if exposing the solar cell doesn’t work.

          1. Thank you so much for your quick and thorough reply. It’s much appreciated. Also, I accidentally just hit ‘report comment’ instead of reply. I’m sorry :(

  5. Creative hack, but … just project the eclipse through some cheap binoculars .. you can blow it up as large as you like. I went to Walmart today, bought some cheap $20 binox and projected the sun onto a sheet of paper, just to test it out. It was easy to see sunspots, and to project crisp silhouettes of branches when the sun was setting behind some distant trees .. just put a large disk of cardboard around the objective of the binoculars to ensure that there is a nice patch of shade for the sake of contrast and you’re set.

  6. Nice hack but the auto helmet you have must not be of any quality. Any of the Miller and Lincoln helmets have a feature where you can control the sensitivity and shade level. These helmets are really nice to keep you protected throughout the day. NASA recommends a shade 13 to look at the eclipse. I would buy a $15 Hobart helmet with a FIXED shade of 12 or 13 installed. *Warning* Please do not buy Harbor Freight helmets for this eclipse. Your eyes are too valuable to be protected by Chinese crap.

  7. My HF auto darkening helmet will trigger from the reflection of the sun off of a piece of sheet metal, nevermind looking at the sun itself. Haven’t ever used an auto darkening helmet that *doesn’t* get triggered by reflections while I’m setting up to weld.

    1. It’s good that your helmet works like that… but not every helmet works like that. Consider for a moment that during the eclipse, the sun is not the same as it is now. Maybe it will work, maybe it won’t.

  8. I would like to use my husband’s Lincoln mask with my kids today, but will not chance it if there’s a risk. It is adjustable 10-13, so I moved the dial to 13 and adjusted the sensitivity to high. There’s a time delay, too, not sure if that matters. Other than that, I do not know what I’m doing as I’ve never used it before. :-). Advice? It just looks green inside but seems to be auto-on?

  9. How do you determine the Shade Value of the lens? Is there a marking, code etc. which identifies its value? I have a regular welding hood, made in the USA, but do not recall its shade value.

  10. DUDE ! Thanks for this vid. We live in Florida- and my 6 year old girl was psyched for the eclipse… I caught this vid about 20 minutes before our “maximum coverage…. Our helmet wasn’t as kick ass yours :) I ended up having to use aluminum foil for my cover and duct tape for the remote because I only had a big remote. My kid literally freaked out when it worked…. she called her mom at the school where she works (about 2 mins away) and said she has to check it too ! Ended up almost every staff member and teacher got to use it- and enjoy the eclipse as well. Can’t thank you enough for this and just in time !

    1. That is incredibly cool. Similarly, I have a small space inside a larger industrial complex, and ended up passing a helmet around to many of my neighbors… which was fun, but I bet that wasn’t anything like seeing your daughter light up. Cheers Chris! Thanks for commenting, much appreciated.

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