Night Vision vs. Ultraviolet Vision

[bjbrown]

I am unable to detect a situation in which ultravision might be more advantageous than night vision. Both seem to have the same effects (allowing a character to see in normal darkness). However, ultravision is limited or useless when no ultraviolet light is available (underground, cloudy night), while night vision does not seem to have any corresponding limitation. Is this a correct interpretation?

[Steve Long]

This isn't a rules question, so I've moved it. In any event, I'm not a scientist, so I'm not qualified to discuss the prevalence or usefulness of ultraviolet light and thus UV vision.

[RadeFox]

Night Vision is BETTER then UV, period. There is no limiting factor built into it. But it does not make sense for many 'realsitic' entities to have it. Very little if any life on earth could be considered to have NightVision (which in my game I would call DarkSight, since UV is closer to nightvision in my mind). But there are many types of life that have evolved excellent low lifght or UV visions. So in terms of play/GMing style, UV tends to see more use, I would think.

And to note UV radiation penetrates cloud cover with ease, you can still get a sunburn [caused by UV rays] on a cloudy day as well a sunny one, or so the Weather Channel says. :p So I would likely allow UV vision to work in cloudy conditions, unless it was severely overcast/storming.

However, I could see good logic in lowering UV vision to 3 pts, since, it is significantly limited over NightVision. (not useable indoors(away from windows) or undergound is damn near a -1 in my book). I think Infrared is still worth 5 in that it has many other uses, detecting undead, androids, orimages masquerading as normal folks, or spotting hot spots that could be hidden entrances or underground power sources, etc.

If you wanted to add in a limit of some sort to NightVision (and IR) to keep all three worth 5 pts, you could very realistically add in a Flash side effect with NV (1-3 d6 would be fair, imo), if you suddenly percieve a bright light (lantern, etc) with NV, same with a strong heat source and IR (a torch thrust at your face, etc).

[Sociotard]

There are many uses for looking into the ultraviolet that can't be done with mere darksight. For example, Ultraviolet can punch through clouds quite easily (I think), so I bought it for one of my satelite followers so he could see the ground more often. Things get even more fun if you buy it as being active, meaning ultraviolet beams shoot out your eyes. Ever watch CSI? You see the strangest things under that purple glow. Come to think of it, I wonder if a GM would let me give my opponents melanoma this way. Glaring. Slowly.
Okay, I don't really know what I'm talking about here, but Ultraviolet does have it's uses.
http://imagers.gsfc.nasa.gov/ems/latest_eit_171.jpg
The sun as seen in the far ultraviolet
http://cache.corbis.com/agent/11/57/15/11571572.jpg
A desert hairy scorpion under a UV light. remember, making a sensory power active is free.

[Farkling]

Nightvision won't percieve the invisible marks left by MazeMan's vaseline magic markers. Ultraviolet can spot certain fabrics by the "imaging" given in the ultraviolet spectrum (cotton comes quickly to mind)...certain minerals will have that "green glow" to UV vision...I allow character's to see some lower powered radiation emissions/traces with it (alpha/beta particles). And the CSI effects would certainly allow for a few Criminology or Forensic bonuses...in a futuristic setting, it might allow visibility of certain weapon packs or energy discharges also. There are other uses too...but they escape me at the moment. :)

[Toadmaster]

I don't have FRED with me at the moment so it may discredit some of this but the way I interpret IR, UV and Night vision is as follows.

Active senses require a "light source", passive senses use ambiant "light".

IR - sees in the infrared spectrum of light, you may use an IR light source (flashlight etc) which is invisible to normal sight, some IR light must be present to see, this is what early night vision used. There are not a lot of natural sources for IR vision to see by, so an IR light source will be required, an IR user can detect the "light beam" from an IR source just like you can see a flashlight beam. Some reptiles have a limited form of IR or Thermal vision (pit vipers for example). This or Thermal vision is closest to D&D IR vision.

An off shoot is Thermal vision, this sees the changes in heat patterns (think Predator) so it may be used in complete darkness as long as the target is significantly warmer or cooler than the surroundings. It may also see through many obstacles to normal sight (smoke, haze etc) unless it is an extreme temperature differance (white phosphorus smoke (hot), discharge from a CO2 extingusher (cold). It can also be used to track things, places that the trackee touched will change temperature for awhile so it may be possible to follow the warm (or cold) footprints, tenticle prints etc. Other special effects could include seeing which people just came from inside a warm building, cars that are still warm from being driven etc.

UV - This is the opposite end of the light spectrum from IR, it uses UV light in a similar manor to IR, but UV light is more common in nature (most likely someone with UV vision will have plenty of light to see by in sunlight), a UV light source invisible to normal vision can also be used if needed. UV also has some advantages over normal vision because camoflage is made for normal vision, it often has no value vs other light sources, consider hunter orange camoflage, vs the animals who have black and white vision it works great, against people who have color vision it jumps out, similar effects happen with other forms of vision unless it has been designed to work against that vision. As mentioned elsewhere UV also makes certain chemical compounds stand out. Many insects can see in the UV spectrum. D&D UV vision is really better represented by night vision.

Night vision - Or better put low light vision, this is light intensification as used by modern night vision sights (also known as starlight scopes), the available ambiant light is magnified thousands of times allowing normal vision in light conditions that most would call darkness. Some light is still required but not much, a candle would allow a night vision user to see like a sunny day. Flash for being suddenly exposed to normal light would be a reasonable side effect / disadvantage. Many night vision devices can detect IR or UV light and include a small IR or UV light source for use in complete darkness.

Night vision usable in complete darkness would most likely have to include some sort of active sense, light projection (IR/UV), radar, sonar etc.

This is how I compare these to real vision devices. This may not match up 100% with the actual rules.

[Farkling]

I'd forgotten about the camoflauge effect vs IR or UV...I thought most military cammies compensated for that.

I'll bet the "off the rack" stuff doesn't though... hmmm.

[Trebuchet]

Originally posted by Farkling
I'd forgotten about the camoflauge effect vs IR or UV...I thought most military cammies compensated for that.

I'll bet the "off the rack" stuff doesn't though... hmmm. Military camouflage clothing does block IR, and camouflage netting does as well. So far as I know it doesn't block UV, but I don't know of any military systems that use the UV spectrum to see with so the point may be moot.

The human eye can percieve UV, but most of it is blocked by our retina. Many animals can see into the UV spectruum, so most "off the shelf" hunting camouflage blocks UV. Most off-the-shelf laundry detergents such as Tide or Fab contain UV-enhancing "brighteners" which many animals can see, (and humans to a limited extent as "brightness") so hunter's suppy stores and catalogs sell special non-UV-enhancing detergents. Wearing clothing washed with such brightness enhancers is like wearing neon clothing to deer and many animals.

[Farkling]

Thanks Trbuchet...I'll add that to my note files..

This could have some uses after 3 or 4 game sessions of the SuperSpies game...

[badger3k]

Originally posted by Toadmaster
I don't have FRED with me at the moment so it may discredit some of this but the way I interpret IR, UV and Night vision is as follows.

Active senses require a "light source", passive senses use ambiant "light".

Night vision - Or better put low light vision, this is light intensification as used by modern night vision sights (also known as starlight scopes), the available ambiant light is magnified thousands of times allowing normal vision in light conditions that most would call darkness. Some light is still required but not much, a candle would allow a night vision user to see like a sunny day. Flash for being suddenly exposed to normal light would be a reasonable side effect / disadvantage. Many night vision devices can detect IR or UV light and include a small IR or UV light source for use in complete darkness.

Night vision usable in complete darkness would most likely have to include some sort of active sense, light projection (IR/UV), radar, sonar etc.

This is how I compare these to real vision devices. This may not match up 100% with the actual rules.

Good descriptions - the best I've heard yet.

The rules have nightvision give it as passive sense, with the description of allowing sight in total darkness. The only problem I have is the write-up - +4 PER only to counteract the darkness modifiers. The modifer for a dark night is -4, which to my mind is a lot different than total darkness.

To my mind, in a more modern style campaign, nightvision as given in the rulebook is more in line with the light enhancement as you describe it. Now in a fantasy campaign I'd be more inclined to follow the written description and make it a "magical sight" ability and let it allow vision in pitch black conditions.

[Toadmaster]

I would think total darkness as in the complete absense of light would be like the power Darkness blocking all "normal" vision, while just extreme low light conditions would be a penalty allowing night vision a boost over normal vision (starts +4 levels higher up the penalty chain) so nightvision sees as well on a dark night as normal vision does during the day but perhaps deep within a cave with just the slightest amount of light reaching in from the entrance would be like a dark night. I suppose at some point it becomes "darkness" (-8 to-10 perhaps?). I agree that some fantasy vision seems magical in nature and nightvision that can see in complete darkness makes sense, such as many games Dwarves having "darkvision" which is able to see while deep underground, then again perhaps dwarves have a natural phosphoresance like some deep sea fish, but in this case its only visable to dwarves.

[Dust Raven]

UV has loads of uses, none of them making it more or less effective than Nightvision.

Buy a small Cosmetic Transform (target into target that glows UV) and once you've hit him with it, you can following him from very far away because he'll glow like a torch.

You can use it to see character that are invisible to only normal vision (which, IMO, includes Nightvision).

And you can use it to read secret messages passed between you and your superhero girlfriend in history class. :D

[Toadmaster]

Plus all of these vision types can be combined, Predator 2 being a good example, the guys "hunting" the Predator blocked his? IR / Thermal vision so he just switched over to what I assume was UV vision.

[badger3k]

Originally posted by Toadmaster
Plus all of these vision types can be combined, Predator 2 being a good example, the guys "hunting" the Predator blocked his? IR / Thermal vision so he just switched over to what I assume was UV vision.

Cool effects too (played some aliens vs predator 2 a few days ago - switching vision is sweet - love the preds)

Add in a good detect or two (sense life maybe) and you can cancel all those pesky problems of light and darkness - just don't forget flash defense though, otherwise you might not be able to switch the vision powers.

[PhilFleischmann]

Don't know for sure, just speculating on what has been said so far:

If you're underwater, IR or Thermal vision (which I thought were kind of similar if not the same) would not let you see fish, because they're the same temperature (or very nearly so) as the surrounding water. But it would let you see dolphins and other marine mammals, because they're warm-blooded. Is this right?

I also have always found the "+4 Nightvision allows you to see in total darkness" to be suspect. A dark night with very little light I might buy, but total darkness seems like far more than a -4 penalty.

[Dust Raven]

I think you are right about the fish in the water thing. Another thing to keep in mind though, is that IR only has a range of about 5-15 feet underwater. The funny thing about water is that it soaks up light, starting with the infrared and working iis way down. UV would be the last to go.

IMO, the only difference between IR and Thermalgraphic vision is that Thermo is bought N-Ray.

[Farkling]

It says right here on the table on pg. 229...
Dark Night -4
I guess you could throw in low contrast for another -1,
but I guess I'd put a new moon night at -6 with the -1 for low contrast right on top of it...for a grand total of -7.

Maybe once should just buy N-Ray:: Blocked by light. :)

[Trebuchet]

Originally posted by Farkling
It says right here on the table on pg. 229...
Dark Night -4
I guess you could throw in low contrast for another -1,
but I guess I'd put a new moon night at -6 with the -1 for low contrast right on top of it...for a grand total of -7.
That would seem to imply that night is a lesser condition of darkness than being at the bottom of a mine shaft, which is how I would apply it. Nightvision counters the -4 penalty, but IMHO confers no ability to see in absolute darkness. To see in total darkness, you'd need some sort of N-Ray vision, although obviously Infrared would still allow you to see heat traces.

Low contrast I think means "wearing black clothing at night" more than "It's dark so you can't make things out." A dark night is already a night of a new moon, a full moon-lit night might only be -2 or -3. Most nights anywhere near a city will never be worse than this unless there's a blackout; modern cities normally produce a tremendous amount of "light pollution." (Although that depends on the location; earlier this week I saw a picture online taken from the space shuttle of the Korean penninsula. The difference between North and South Korea was astonishing. North Korea had only a few pinpricks of light; South Korea was lit up like a Christmas tree.)