Could church domes be used to project clouds on the floor?

  • Context: High School 
  • Thread starter Thread starter farolero
  • Start date Start date
  • Tags Tags
    Project
Click For Summary

Discussion Overview

The discussion revolves around the concept of using church domes as camera obscuras to project images of clouds onto the floor. Participants explore the feasibility of this idea, referencing historical examples and personal experiences with similar optical phenomena.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant cites a book mentioning the use of a lens in the oculus of Notre Dame's dome to project clouds during Napoleon's funeral, questioning if this could be replicated in modern churches.
  • Another participant asserts that any enclosed space can function as a camera obscura, suggesting that the floor-lens distance should match the focal length for optimal image projection.
  • A participant expresses curiosity about the lack of references online regarding the use of domes as camera obscuras, highlighting the potential appeal of such an experience in a church setting.
  • Concerns are raised about the need to black out other windows to enhance the projection effect.
  • One participant shares a personal anecdote about achieving a clear image of the sky using a small hole, emphasizing that even without a lens, similar effects can be observed.
  • Another participant describes a past experience with a pinhole camera effect, noting the significance of such optical phenomena in appreciating physics.

Areas of Agreement / Disagreement

Participants generally agree on the technical possibility of using domes as camera obscuras, but there is no consensus on the practicality or existing references to this idea. Multiple viewpoints and personal experiences contribute to the discussion without resolving the feasibility of the concept.

Contextual Notes

Participants mention various conditions that could affect the projection, such as the need for specific lens placements and the impact of ambient light from other windows. These factors remain unresolved in the discussion.

farolero
Messages
166
Reaction score
10
i read it in this book , check the page:

in napolen funeral notredame dome was set a right lens oculus to project the clouds around napoleons corpse

https://books.google.es/books?id=F1...=onepage&q=camera obscura church dome&f=false

so could be a church dome trully be used as a camera obscura to project the clouds on the ground of the church to give it a magical look?

wouldnt it just be a question of setting a right lens in the oculus of the lens?
 
Science news on Phys.org
Any enclosed space can be set up as a camera obscura.
To get a good image of the sky on the floor, you set the floor-lens distance to the same as the focal length. Get a lens and give it a go.
 
  • Like
Likes   Reactions: farolero
thanks a lot for confirming this fact :)

what i wonder now is why there's no other reference on the web to the posibility of domes of acting as camera obscura if the right lens set in the oculus but that obscure book i linked

it would be quite appropiate to project the clouds in a church with the aid of a dome, i would visit any church to walk on clouds in an ancient flight simulator
 
You might also need to black out other windows.
 
  • Like
Likes   Reactions: Simon Bridge
farolero said:
i would visit any church to walk on clouds
Shame your shadow would be all over the floor. (And that of everyone else, too.)
 
  • Like
Likes   Reactions: Simon Bridge
CWatters said:
You might also need to black out other windows.
I used t do this every day as part of an undergrad teaching lab - "find the focal length". You can get quite a good image of the sky on a bright day even outside - though it can help to direct the image to a part-shaded area. On a cloudy day, we just used the lab ceiling lights.

I imagine the "lying in state among the clouds" thing would look best when viewed from a mezzanine gallery which many domed churches have.
If the surface colors were handled right, there would be a strong effect of lying in the clouds.

I have had the "walking in the sky" vertigo swimming at night, under a clear sky, on mirror flat water.
Ripples spoil it - but just stand still and the illusion of stars below me was very strong.
 
  • Like
Likes   Reactions: sophiecentaur
When I was a kid there was a squared tunnel that led to a large aqueduct. The tunnel was over 15 feet tall, long and curved just enough that it was pitch black in the middle section. There was an access spot with a sewer top next to ladder rungs implanted into the wall. The near 1 inch hole in the sewer worked well enough to produce a clear image of the sky and a telephone pole on the floor with no lens.
 
  • Like
Likes   Reactions: sophiecentaur
I remember a great chance 'pinhole camera' effect when there was a large image of the Sun on a wall, from a keyhole in a door at the top of the stairs, 15m away. Great view of some sunspots at the time. You have to savour these things when they occur and Physics makes its presence felt.
 

Similar threads

Replies
4
Views
11K