How to Paint a Bubble?

# Thread: How to Paint a Bubble?

1. ## How to Paint a Bubble?

I'm currently working on a large painting that involves multiple bubbles, but I don't understand how they work in regards to light. Could anyone explain to me the "anatomy" of a bubble? Thank you thank you

2. well it is a primarily transparent surface and highly reflective so how it looks is dependant on its environment. If you are making it up you are in for a lot of geometry math to calculate the correct reflections on curved surfaces.

3. Jester Level 8 Gladiator: Thracian
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Study the real thing and go from there...

4. Originally Posted by dpaint
well it is a primarily transparent surface and highly reflective so how it looks is dependant on its environment. If you are making it up you are in for a lot of geometry math to calculate the correct reflections on curved surfaces.
Yeah, that's what I figured. I guess the best way to go about this is to try to figure it out and post it on CA for critiques.

Originally Posted by eezacque@xs4all.nl
Study the real thing and go from there...

5. I guess the thing I always noticed about bubbles is no matter what the environment, they always have a pink-green alternating sheen to them-- the kind you see in gasoline.

6. ^ It's called iridescence. When light hits a thin transparent film it causes some of the light wavelengths to cancel themselves out because of how they line up. So from different angles you'll loose different colors of light. Basically you'll be seeing the specular reflection of the environment in the bubble, except some of the colors will be shifted towards another hue.

As far as specular reflections go, you don't really need to do a lot of maths to figure it out. Just remember that the angle of reflection equals the angle of incidence... Which sounds complicated, but it isn't really.

Thus, anything that's facing 45 degrees away from you will reflect what's right to the side of it, and anything beyond that (the edge of a bubble for example) will reflect what's behind it. You could calculate all this stuff if you wanted to. But I'm pretty sure you'd get a feel for it with a little bit of practice.

Also. Specular reflections get stronger the further away from you that a surface is facing. I'm not entirely sure why this is... but I'm sure there's a fancy explanation for that as well. So if you're looking at a surface straight on, you'll see less of a reflection than if you're looking at it from an angle.

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Originally Posted by tobbA
As far as specular reflections go, you don't really need to do a lot of maths to figure it out. Just remember that the angle of reflection equals the angle of incidence... Which sounds complicated, but it isn't really.

[...]

Also. Specular reflections get stronger the further away from you that a surface is facing. I'm not entirely sure why this is... but I'm sure there's a fancy explanation for that as well. So if you're looking at a surface straight on, you'll see less of a reflection than if you're looking at it from an angle.
There is a critical angle, beyond which light is not penetrating anymore, but will be reflected. Also, the basics of reflection are as you summarize, but things will get complicated on curved surfaces. Finally, there is refraction, which distorts things if we look through a bubble...

9. Remember, because bubbles are transparent and hollow, you will have two reflections.

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11. As Tristan says...

More detail, less convincing...

12. I feel like any one of those infants could kick my ass. Jeez.

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14. Chardin

15. Originally Posted by Chris Bennett
More detail, less convincing...
Pretty much sums up Holman Hunt's entire oeuvre.

16. You could always take some pictures of bubbles outside. When my nephew and I were playing with those large bubble-wands, you get some great curve details with the way that the oil reflects around the edges of the bubble.

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