Pinhole camera

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allhoest
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Pinhole camera

Post by allhoest »

The small experience to practice during eclipses: the “Pinhole” camera.

What diameter should the hole have?
How big will the image be?
What is the resolution of the image?

This post on Cloudynights gives the answers:
https://www.cloudynights.com/topic/5700 ... -eclipse/


To reproduce this effect, I made a plate with holes of 1.5, 2, 3, 4 & 5mm.
The threaded rod towards the center of the plate serves as a solar finder.

Image



Here is the result during the eclipse.

Image


Alex


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Re: Pinhole camera

Post by christian viladrich »

Nice demonstration Alexandre !


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Re: Pinhole camera

Post by KMH »

Very nice!

Kevin


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Re: Pinhole camera

Post by rsfoto »

Good idea.

In your case it look like 1mm gave the sharpest image but also I guess it is a question of distance. The bigger the hole the farther away it has to be. Look at the result using the leaves of a tree. The distance of the holes is big but also the distance of this holes to the ground is big.


regards Rainer

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Re: Pinhole camera

Post by allhoest »

rsfoto wrote: Thu May 09, 2024 3:51 pm In your case it look like 1mm gave the sharpest image but also I guess it is a question of distance. The bigger the hole the farther away it has to be. Look at the result using the leaves of a tree. The distance of the holes is big but also the distance of this holes to the ground is big.
Yes the pics are sharper with the smallest hole, but also fainter, as less light is passing through. Hence, I went for 1.5mm as the smallest hole.
The distance of the pinhole plate to the white cardboard was about 1.1m, so the same for all.

You can experiment this distance / diameter without the eclipse but with a tree (any "sharp" piece) in the path.
The image of the piece will be sharper with the smaller hole.


Alex


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Re: Pinhole camera

Post by rsfoto »

allhoest wrote: Thu May 09, 2024 8:35 pm
rsfoto wrote: Thu May 09, 2024 3:51 pm In your case it look like 1mm gave the sharpest image but also I guess it is a question of distance. The bigger the hole the farther away it has to be. Look at the result using the leaves of a tree. The distance of the holes is big but also the distance of this holes to the ground is big.
Yes the pics are sharper with the smallest hole, but also fainter, as less light is passing through. Hence, I went for 1.5mm as the smallest hole.
The distance of the pinhole plate to the white cardboard was about 1.1m, so the same for all.

You can experiment this distance / diameter without the eclipse but with a tree (any "sharp" piece) in the path.
The image of the piece will be sharper with the smaller hole.


Alex
Hi Alex,
The image of the piece will be sharper with the smaller hole.
Did you test different distances and the smallest hole was always sharper?


regards Rainer

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Re: Pinhole camera

Post by allhoest »

Sorry, I have not done the test. Maybe for the next eclipse.
I'm quite busy and will concentrate on other tests first.
CS
Alex.


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Re: Pinhole camera

Post by Montana »

That's a lovely little experiment, I had never thought of size and distance before. I took a sink strainer with me and just moved it about till I got focus :)

Alexandra


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Re: Pinhole camera

Post by rsfoto »

Montana wrote: Fri May 17, 2024 10:22 am That's a lovely little experiment, I had never thought of size and distance before. I took a sink strainer with me and just moved it about till I got focus :)

Alexandra
Hi,

I guess that proofs my Theory about distance and hole size

:?


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