Real life experiments with lighting

edited June 2015 in Story Games
I have been enjoying some OSR gaming recently, in which I've been paying a lot more attention to light than previous D&D. Which of the party are carrying lanterns? How much does that really illuminate? I have been trying to work at describing the shadows, the way the light flickers when they move, what fighting by moving torchlight is like. It's been great fun.

However, all I really have to go on is what various D&D texts have told me over the years about how much light a candle, a torch, or a lantern shed. The standard rules for a torch in 3.5 are 20 feet of bright illumination, and a further 20 feet of dim illumination. A lantern is a bit more than that, whereas a candle only gives 5 feet of dim illumination. (SRD link).

I thought it would be fun and interesting to experiment with this myself*. So my plan is to go to some shallow caves next time I'm visiting my relatives in the country. I'm going to take along candles, homemade torches, and so on, and do some experiments into how much I can see. I don't think I will be able to photograph or film the results, but I hope to describe them on my blog. This will then fuel my descriptions / rulings when I GM.

I would be interested if any of you here knew of anyone else doing similar and having written it up on the web or in a roleplaying text already. I would also be interested to know if anyone has practical experience of doing things by fire light, or if anyone else wants to do the same sort of thing and tell me their results. I realize that as a UK-based gamer, I am one of the worst placed to do anything like this, compared to all you Americans and Scandinavians!

* Note that as far as roleplaying goes, so long as our world is consistent and flavourful it doesn't really matter whether our lighting is realistic. So this is for fun, rather than an obsessive necessity with getting the rules "right".

Comments

  • edited June 2015
    Here is my rough list of ideas so far, including notes to myself on the big gaps in my knowledge as yet!

    Sources of light to test:
    * Candle - preferably a poor quality tallow candle, as well as a high quality one, such as beeswax
    * Torch - here's a basic starting point for how to make one, but I welcome advice from those who know something about this. Outstanding questions: Use cloth or rope around the top? What kind of rope/cloth is historically accurate and what's the closest thing I can get hold of? Ditto for the flammable starter - wax? pitch?
    * Oil lamp - What kind of oils are available today? What would be historically appropriate to a traditional D&D setting?
    * Oil Lantern - this is probably the most expensive thing to do, as I would have to buy a proper glass lantern.
    * Multiple candles
    * Multiple torches

    Experiments:
    * What's it like standing still? How much of the caves can I make out?
    * Get someone else to move closer and further away. How much can I make out at different distances? Can I see their expression?
    * What's it like trying to move around with light source? If safe enough to try, what's it like trying to swing a weapon with the light source in the other hand?
  • edited June 2015
    This sounds like a really fun project that will be viewed with intense interest by many. I have never seen any real world illumination experiments!
  • edited June 2015
    If you wear protective accessories, you might also test that favorite Lovecraftian maneuver: "Running at full-speed through a dark maze of tunnels while carrying a flashlight."

  • Sounds like fun! Please post here as well when you're done, at least with a link to your blog.

    Some other experiments I would be interested in, on things I've thought about when I GM:

    * If the first person carries a torch, how much can the second person see? My current module (The Dead Forest from 1985 for the Swedish game Drakar och Demoner) says that everyone behind the one carrying the torch are blinded by it.
    * What happens if you drop a torch on the ground? Does it always go out, is there a 1 in 6 chance, or does it never go out? It obviously depends on how the torch is constructed, but would still be interesting to try.
    * How much difference in illumination is a torch lying on the ground compared to being held in the hand? My PCs usually drop a torch when they start fighting, but I wonder if it's then possible to see anything.
    * If you have two assistants, have one person stand still with a torch and the two other "fight". How much does the fighter facing the torch see of its opponent? How much does the fighter with its back to the torch see? Facing the torch, you should be fighting a silhouette.

    Illumination by a torch in my Drakar och Demoner module is 5 meters. You get -25% to-hit when you fight in torchlight. It would be interesting to see if that's fair.

    So far, when we've played Whitehack with the above module, I've not given any reduction to hit in torchlight, but perhaps I should. It would really make monsters that see in the dark more scary.

    If you want to try a simple lantern with glass sides and a candle, you can find one at IKEA. Based on pictures I get the impression that you can turn up an oil lamp to be a lot brighter than a candle, so perhaps a candle lantern is not very useful to the experiment.
  • Jonas, thanks for those suggestions - they are all great, and are exactly the kind of thing that would be interesting to me as well. Particularly the torch on the ground one - my players want to do that kind of thing all the time.

    Aslf, I won't be running, almost certainly, as I'm trying to keep this safe, but I do intend to also play around with electric torches. But I guess most of us have a pretty good idea already of how much we can see with those.

    Jason, thanks for the encouragement!

    I will certainly post the results, or a link to the results, in this thread when I am done.
  • edited June 2015
    Some friends of mine took a torch out into the woods to test illumination. They said that beyond about 30 feet it was useless. That's the only part I remember for sure, but I think they also said:

    - It ruined their night vision and made them easy targets so much so that going by even dim moonlight would have been better for most adventuring purposes. But with a thick enough forest canopy, at least a torch could help you from walking into stuff in pitch blackness.

    - A person with the torch in their field of view (as opposed to the one holding it above eye level) was effectively blind to everything except the torch itself.

    - As for how visible it made them, I think the actual torch itself was visible for a long ways off (a thousand feet?) if not blocked by trees, but the light it threw off (onto people, trees, etc.) was not. That's my own experience from peering at torch-sized campfires, anyway.

    I imagine all this depends somewhat on the type of torch, e.g. if one is able to keep a dim glow going as opposed to a bright blaze. I don't know anything about who used what sorts of torches in the real world, but I imagine some info is out there about someone's best practices. Even if you don't dig that up, I'd be curious to hear attempts at varying torch brightness.

    As far as simulating hostile encounters, I'd be curious to see, if a non-torch wielder emerges from the darkness to charge the torch-wielder, which of them gets discombobulated first.
  • David, that's interesting stuff about using the torch in the wood. So far I have mainly been thinking about dungeons - underground natural or artificial cave systems which would be absolutely dark without some kind of artificial illumination. But in low-light conditions - starlight, dim moonlight, bright moonlight, phosphorescence - is it better to rely on the existing light or what you have brought with you? I wonder if I or someone else can repeat the same tests I'm planning for the cave in lighter conditions.

    Would your friends be able to post here? If not maybe you could ask them for more details about what they did and what the results were. I'd be interested in how they made / obtained the torch, as well as anything more that they remember about the results.

    The obvious experiment I forgot to include above is reading and writing by these light sources. Adventurers are forever finding books, scrolls, runes inscribed on walls. How easy is it to read them, and how close up to you have to get?
  • The obvious experiment I forgot to include above is reading and writing by these light sources. Adventurers are forever finding books, scrolls, runes inscribed on walls. How easy is it to read them, and how close up to you have to get?
    And mapping! That is commonly cited as a reason for the slow movement in B/X (12 feet per minute). Quoth Moldvay:
    A base movement rate of 120' in ten minutes may seem slow, but it assumes that the players are mapping carefully, searching, and trying to be quiet. It also takes into account the generally "dark and dingy" conditions of the dungeon in which characters are adventuring.
    Drawing a map could be an interesting experiment. The caves you'll visit may not have multiple branching corridors, but you could draw a map of the shape of the cave and of any notable features. You can't carry a torch and draw, and you probably can't move and draw at the same time, so you need someone else to stop and move the torch closer each time you want to update the map.
  • edited June 2015
    By the light of a full moon in a sky that's either cloudless or filled with clouds that aren't blocking the moon, I can see as well as daylight for most purposes. Not all, though. Quick movements far away are less likely to catch my eye, for instance.

    Starlight is great for silhouetting things against the sky, but is not very useful for spotting things on the ground unless they're very bright/reflective. When I navigate campsites or state parks by starlight, I have to move very slowly the first time I traverse a route, otherwise I could easily step in a hole.

    So I think the details make all the difference in "low light" conditions. I'd definitely need a torch for moving at any respectable speed without moonlight, and I definitely wouldn't need a torch with moonlight. It occurs to me that moonrise and moonset are important factors for outdoor adventuring, and I've never found a convenient way to remember how that syncs up with nighttime for a given place/season/etc.

    I've asked my torch buddies to weigh in; I'll pass along whatever they get back to me with.
  • Excellent discussion, and an excellent experiment. I think there's no question that RPG rules generally seriously underestimate the effects of darkness. (I was always dumbfounded by the -4 to hit when blinded or fighting an invisible opponent rule in D&D!)

    I'll add another question:

    In a lot of fiction about this kind of thing, people use "hooded lanterns", largely so they can control loss of night vision, being spotted, and so forth. Presumably it may be handy when moving through a tunnel and then back into the moonlight, and so forth. Does anyone have experience with this?

    My own with moving around in the dark is similar to Dave's, above: at night, the sky makes an enormous difference. If the sky is clear and the moon is out, I can see surprisingly well, once my eyes have adjusted. However, if a cloud passes in front of the moon, or I have to duck under a few trees into a "shady" spot, suddenly you can hardly see anything. Your eyes become very sensitive to minor changes in lighting conditions.
  • edited June 2015
    Isn't a flashlight/electric torch essentially a "hooded lantern"? They're set up so that light only comes out of one part.
  • A hooded lantern would be a good thing to try. I don't know as yet how much of these ambitious ideas are possible to achieve, but I'll add it to the list.
  • edited June 2015
    Here's what my experimenter friend had to say:

    Your description of our findings in the thread is accurate, as far as I remember. Unfortunately, I can't find my notes from back then.

    A few thoughts from what I remember:

    Anything that reflects the light hides everything behind it. So if you're on a path or in a clearing in the forest with a torch/lantern/etc, you can see the first row of trees and brush, but everything past that closest layer is black. We found it was very easy for people to hide in that situation, even with minimal cover and at close ranges. An older forest, with bigger trees and little undergrowth, would presumably be different in this respect.

    Everyone behind the person carrying the torch is indeed blinded by it. And even the torch-bearer needs to be careful to keep it held up and back, so as not to blind themselves. Blocking your line of sight to the torch itself (e.g. by holding your hands between your face and the torch) helps a lot, but is impossible to maintain when you and the torchbearer are moving.

    My vague sense of what it would be like to try to fight by exterior torch light (we didn't try it) is that it would be harder to read an opponent's movements and so e.g. anticipate attacks. But seeing where they are well enough to hit them is no problem at melee ranges.

    Jonas's question about what happens if you drop the light is an excellent one. My sense is that it might dramatically cut down on effective illumination (especially if dropped in brush or grass), but we didn't try that.

    From my brief caving experience, in which we used carbide headlamps, which give off a candle-like flame (but with a reflective backplate, so all the light goes more or less to the front):
    the cave walls reflect the light, allowing the small carbide light to illuminate the space reasonably well, at least as far as discerning hazards and creatures is concerned. I think you could read just fine, too, but don't remember for sure.
    the lesser light and greater reflection off the walls means less blinding. In the woods, the torch hindered our vision more than it helped unless we were very careful with it. In the caves, I don't remember having problems with being blinded by other people's lights unless they pointed them right in my eyes from up close.
    it is quite hard to tell where the "exits from the room" are. Deep shadows from indents look pretty much like deep shadows from passages until investigated further, and there are lots of the former.
    Very few of the cave spaces I was in were very big, though, so I don't have a good sense for things like "at how many feet could you see a human-sized figure?" In the few larger chambers, everyone I was with had a light, so they were clearly visible. I didn't get to try having anyone hide in the dark. Most chambers were small enough that anything in there with you was pretty obvious, even if it didn't have a light of its own.
    For the record, I was in J4 in Pennsylvania and one other cave near there that I don't remember the name of. This was 1997 or 1998.

    A side note:
    Aslf mentioned testing the "Lovecraftian maneuver" of running through the cave with a flashlight. I have little sense of how that would be, and would love to know. :) But fwiw, the real caves I've been in had almost no places where one might run any significant distance. They're never level for very long, the floor is sloped (often dramatically) and often covered in slippery mud and/or loose rubble, the ceiling is frequently so low you must stoop or crawl, and the whole place twists, turns, and slopes incessantly. Trying to map the thing would be a nightmare. One of the major things I learned from that experience is how inaccurate the model of more-or-less-level rooms and corridors is w.r.t. real-life natural caves. To test an environment more like what we usually game in, one might have to go to catacombs in Europe or some such. I've never tried to incorporate a realistic cave into my games, because it's so impossible to verbally describe their shape.
  • Caver by day job here ;) I am curious to see what you'll get. We've played around with this a little.

    * Torch - here's a basic starting point for how to make one, but I welcome advice from those who know something about this. Outstanding questions: Use cloth or rope around the top? What kind of rope/cloth is historically accurate and what's the closest thing I can get hold of? Ditto for the flammable starter - wax? pitch?

    Did some linen wraps soaked in pitch. So smokey!!! The smoke is a big killer for vision and well breathing.

    * Oil lamp - What kind of oils are available today? What would be historically appropriate to a traditional D&D setting?
    Olive oil would probably work pretty well. There a lots of clay olive oil hand lamps you can get on the cheap.

    * Oil Lantern - this is probably the most expensive thing to do, as I would have to buy a proper glass lantern.

    Maybe look at the rawhide lantern, certainly more affordable and much easier to make.


    Experiments:
    * What's it like standing still? How much of the caves can I make out?

    There will be a lot of variation in how much you can see. In basalt caves (just came out of one a week ago) we can't see shit even with high powered modern LEDs. Limestone or gypsum caves are so much brighter.
  • edited June 2015
    In my youth, we made terrycloth torches with wire to help hold them and lighter fluid. Not 'authentic' but reasonable approximation.

    We then explored drain tunnels all over my neighborhood, some of which were long enough to be pitch black. Otherwise, frequent manhole covers and street drains let in light, so it was a lot like a near-surface cave system.

    I can confirm that anyone with the torch in line of sight was blinded. I can confirm that dropping it would often knock it out (but, again, non-ideal design). Dropping it in residual water ruined it. I can also confirm that when thousands of cave crickets were on the ceiling of a tunnel and the smoke hit them, they impersonated popcorn. And we screamed and ran like hell. Or, rather, waddled, because the tunnels were maybe three feet high. Finally, I can confirm that wielding any weapon longer than a short sword is impossible in those tunnels.

    Be safe, good luck, and please publish results!
  • These are some neat videos that might give some ideas of starting points and other considerations (assuming the data is accurate):

  • Continuing thanks for everyone's contributions.

    I've now done some research, and I'm beginning to make prototypes.

    The thing that is puzzling me at the moment is the difference between lamps and lanterns. As far as I can tell the terms are used somewhat interchangeably, and the main difference is that lanterns tend to have an enclosed flame, whereas lamps have an exposed wick.

    If this is correct, can anyone think of a reason why the 3rd edition authors gave a lantern double the range of a lamp? The lantern is listed as "hooded", but googling "hooded lantern" just returns D&D related results.

    I can see how a bullseye lantern could have longer, but more focused range, but that's not what the SRD is talking about here. Is D&D just talking nonsense? Possibly the authors were thinking of modern kerosene lanterns which burn brighter than the oils used in oil lamps, but I think in the high middle ages people would have been using the same oils in both.

    Oh, also I found this forum post: http://odd74.proboards.com/thread/7265 from someone attempting a similar thing to me. They post their conclusions for play, but not much detail on how they arrived at them.
  • They may have been thinking of kerosene lanterns, yes. I suppose candles and lamps would be essentially useless outdoors.
  • edited June 2015
    I don't remember where I found the link, but I saw this on Reddit a while back: We've all seen the unrealistic torches used in Hollywood movies, but what were actual torches like during your period of speciality? How were they constructed, how effective were they, and how long would they burn?

    This comment mentions a book on the subject that seems interesting: A. Roger Ekirch - At Day's Close, Night in Times Past (2005). Quote from the post:
    In his discussion of how past people lit the dark (wax and tallow candles, oil lamps, rush lamps, etc.--just as Lindy Beige's video describes in this thread), he says this about torch construction: "Made from thick, half-twisted wicks of hemp, dipped in pitch, resin, or tallow, a single torch weighed up to three pounds" (p. 124). Torches were not as effective as letting one's vision adjust to darkness: "Human eyesight, in less than an hour's time, gradually improves in the dark as the iris expands to permit sufficient light. Despite losses in color recognition an depth perception, peripheral vision may actually sharpen. Humans see better at night than most animals, many of which are virtually blind" (124).
    That quote made me decrease the number of torches per encumbrance slot in my Whitehack game from six to two.
  • edited June 2015
    My guess about the lantern question would be simply that *lanterns* are bigger and burn brighter than *lamps*. An exposed wick can only do so much, and is affected by wind. Maybe the enclosed lantern can have a much bigger flame, and isn't susceptible to issues like wind.

    I think it's not too hard to imagine how something like this would not give off as much light as something like this.

    Just a guess, of course.
  • edited June 2015
    it is quite hard to tell where the "exits from the room" are. Deep shadows from indents look pretty much like deep shadows from passages until investigated further
    This trick is used often in videogames. And in "Labyrinth". :-)
    Aslf mentioned testing the "Lovecraftian maneuver" of running through the cave with a flashlight.
    I mention it because it happens all the time in games like CoC etc. (usually in the "running for your life" scene), and no one bats an eye. I suspect it's much more difficult and dangerous than most of us imagine.

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