improving refraction tag and dispersion/caustics

so i was updating the tag group:lighting wiki with images and i got stuck on the refraction tag

is there something that can be done to improve the refraction tag? currently it's 90% water refraction that is only visible around the legs and is a very tiny part of the image. it makes it very hard to find images where refraction is the focus. i started putting the posts without water in favgroup:47714 to see what they look like. so far i found a few types of posts that could be separated

the average refraction post... it's just someone with legs inside water and they look distorted because of refraction

refracted light, this looks completely out of place in the tag...

water refraction but it's a container instead of a pool, ocean or bathtub

seeing someone through glass shards, bubbles, glass balls, glass cubes or eyewear that changes the angle of light

this lens effect when you have water inside a glass cup

so one problem is refracted light can be caustics or it can be dispersion (optics), but i don't know if it's always going to be one of these two since the artist has license to do anything with light particles coming from objects. also some posts like post #9649887 just feel like that's a rainbow colored lens flare instead

caustics also feel like a bad tag imo. the problem is caustics is technically the light that goes through one surface and is projected on another surface. but lots of posts are tagged with caustics that you can only see the surface of water. or it gets tagged with caustics because you can see the wavy surface from underwater

this is just too technical and confusing. i wish there was just a tag you could use that is like shadow but for light. like when light goes through a transparent object, you just use that tag.

trapster77 said:
caustics also feel like a bad tag imo. the problem is caustics is technically the light that goes through one surface and is projected on another surface. but lots of posts are tagged with caustics that you can only see the surface of water. or it gets tagged with caustics because you can see the wavy surface from underwater

Caustics definitely needs help of some sort; a lot of mistags in there.

Placeholder1996 said:

Caustics definitely needs help of some sort; a lot of mistags in there.

tbh is that pattern on the surface even caustics? i thought it was caustics because of the shadow the waves cast but now that i think about it's just a shadow isn't it? does that count?

can an expert in caustics tell me which one of these is caustics?

is this caustitcs?

this?

this maybe?

trapster77 said:
can an expert in caustics tell me which one of these is caustics?

Based on the wiki, post #4150718 post #5042675 post #5069284 are caustics. post #305480 is light rays and not caustics. post #10053971 and post #10026831 certainly aren't caustics; those are just waves. I'd also say the wiki is correct and doesn't need to be changed, aside from maybe adding visual examples.

specifically, caustics is the light pattern caused by a material (usually water). If only the material is in the image (post #10041155, for example), then it shouldn't be tagged even if it shares the pattern.

Placeholder1996 said:

Based on the wiki, post #4150718 post #5042675 post #5069284 are caustics. post #305480 is light rays and not caustics. post #10053971 and post #10026831 certainly aren't caustics; those are just waves. I'd also say the wiki is correct and doesn't need to be changed, aside from maybe adding visual examples.

okay, i added the non-caustic posts to the non-examples on the wiki

Placeholder1996 said:

specifically, caustics is the light pattern caused by a material (usually water). If only the material is in the image (post #10041155, for example), then it shouldn't be tagged even if it shares the pattern.

tbh that doesn't look like waves either. i mean i guess it's not ripples and it's not still water, so it has to be a small amount of waving. but waves is normally for bigger waves

maybe there should be a tag for "water surface caustics" or whatever term should replace caustics

trapster77 said:

tbh that doesn't look like waves either. i mean i guess it's not ripples and it's not still water, so it has to be a small amount of waving. but waves is normally for bigger waves

maybe there should be a tag for "water surface caustics" or whatever term should replace caustics

fair; waves in the physical sense, I guess, if not the one for tagging

If you're going to blanketly remove them they need a new tag and I don't think waves is proper since the tag is largely for images like post #9545889 where the waves are noticeable or crashing on the beach. For images like post #8550805 the artist is trying to draw the light hitting the water, it is not the same concept and needs a tag.

zetsubousensei said:

If you're going to blanketly remove them they need a new tag and I don't think waves is proper since the tag is largely for images like post #9545889 where the waves are noticeable or crashing on the beach. For images like post #8550805 the artist is trying to draw the light hitting the water, it is not the same concept and needs a tag.

fair enough; I'll cease gardening until a new tag is created

zetsubousensei said:
[...]

I'm drawing a blank on a name right now; the only names I can think of either aren't descriptive enough or describe a different phenomenon.