Let's fork this thread since people seem to be as fascinated by this topic as I am…

This process happens in nature. Any lens (a camera lens, the eye) 'calculates' the #FourierTransform of the object being imaged.

Read on…
[1/n]

#Fourier #Optics
The Fourier Transform coincides with the plane of the lens. So small lenses cut out the higher spatial frequencies that are furthest from the centre.

Therefore, these higher frequencies do not go through the lens and they're lost…

[2/n]
So when the remaining frequencies are recombined at the image plane (say the back of the camera or the back of the eye), the terms that are needed for the fine detail are not there…

The image is blurred.

This is diffraction.

[3/n]
So, if you want to calculate the Fourier transform, all you need is a lens!

[END]

• • •

Missing some Tweet in this thread? You can try to force a refresh
 

Keep Current with Stephen Gruppetta

Stephen Gruppetta Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!

PDF

Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @s_gruppetta_ct

Apr 11
What's an image made of?

There are many correct answers.

But the most fascinating one is: << sines & cosines >>

Read on if you're intrigued👇🧵🪡

#python #images #fourier
*Any* image can be reconstructed from a series of sinusoidal gratings.

A sinusoidal grating looks like this…

#sinusoidal #grating Sinusoidal grating
It’s called a sinusoidal grating because the grayscale values vary according to the sine function.

If you plot the values along a horizontal line of the grating, you’ll get a plot of a sine function Cross-section of a sinusoidal grating
Read 18 tweets
Apr 10
A quick introduction: I used to be a physicist, which is where I learnt coding.

As a university academic, coding and teaching were both things I enjoyed.

👇🧵🪡
thepythoncodingbook.com/about/
#coding #python
I always felt that explaining abstract and complex concepts in an accessible way was something I'm good at.

My undergrad students agreed…

And now, so do my coding students, young and, er, not so young…

#teaching #learning
Now I spend my time:
—> running @codetoday_
—> teaching coding to kids & adults
—> writing articles and books on #coding and #Python
—> creating and running Python courses and workshops (coming soon…)

You can read my articles on:
º thepythoncodingbook.com
º @realpython
Read 4 tweets
Apr 9
What frustrates you most when learning to code from books, tutorials, or video courses?

I’ll start… 🧵🪡

#coding #python #learntocode #100daysofcode
1. The instructor cannot understand what a beginner knows and doesn’t know, and assume some things are basic when they’re not for a beginner.
2. “It clearly follows that…”
When following a tutorial, key steps are skipped which are not trivial for a beginner.
Read 7 tweets
Apr 9
Who's Monty & what's a White Room got to do with *truly* understanding concepts in #Python #coding?

What’s more challenging in the early days when you learn coding is to join the dots between various topics you learn, viewing them as a coherent set of tools

🧵🪡
#100daysofcode Image
Here's The White Room analogy in brief:

I call the computer program Monty.

Monty is the one who’s busy doing things, performing all the actions required in your computer program.
But Monty/the computer program needs some infrastructure to be able to operate.

This infrastructure is the White Room: an empty room with white walls and white ceilings–a blank canvas.
Read 11 tweets
Apr 9
One of the best ways to understand a new topic in many non-computing fields is to write a computer program using that topic.

One of the most recent examples for me was drawing using the two-point perspective technique…

#python #drawing #twopointperspective #coding Image
I don't know anything about art or drawing.

My son asked about perspective drawing, so we found some YouTube videos.

They sort of made sense, but…

it's only when I wrote a Python program to draw using two-point perspective that it *really* made sense.
I'm writing a blog to document this learning process, and to go through the code I wrote.

So stay tuned...

#drawing #python #coding
Read 4 tweets

Did Thread Reader help you today?

Support us! We are indie developers!


This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Don't want to be a Premium member but still want to support us?

Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal

Or Donate anonymously using crypto!

Ethereum

0xfe58350B80634f60Fa6Dc149a72b4DFbc17D341E copy

Bitcoin

3ATGMxNzCUFzxpMCHL5sWSt4DVtS8UqXpi copy

Thank you for your support!

Follow Us on Twitter!

:(