Hey friends, Happy Wednesday!

Last week, I hosted a board game night and dinner at my place for the first time with a couple of my friends on Ramzan. Eid Mubarak!

I’m including an extended summary of how a gadget works in my newsletter, from which you can understand the essence in less than 3 minutes. But you can choose to read the blog posts for a more detailed version involving the nuances, from the links I attach.

Let’s look at how an Instant Camera works this week. I aim to write my newsletter issues in a way one can follow them while traveling on a bus, having a coffee, waiting for your food, etc. Let's jump in!

Tweet of the week

I’m sharing a cool fact about gadgets every day on Twitter. And here is one of them for you

Chendur Singaram @ChendurSingaram A spoon under a stream of tap water deflects the water stream to flow along the curvature of the spoon due to a phenomenon called Coanda Effect! It is the tendency of a fluid jet to stay attached to a convex surface due to pressure differences. pic.twitter.com/0pTM5auLyS April 20th 2023 0 Retweets 2 Likes

How does an Instant Camera work?

Firstly, what is an Instant Camera?

Basically, once you click a picture, a blank-white photo film pops out from a slot (Figure 1. Left). And, it takes a few seconds to generate an image of what you clicked (Figure 1. Right) right away! Let’s see how this magic happens!

Simplified Physics of Image Generation

The stack of 10 photo films (Figure 2. Left) is bunched together in a box and placed inside the rectangular slot (Figure 2. Right) of the Instant Camera. The final image is generated on the individual photo films and each of them has all the components & chemicals needed for instant photo generation.

When we click a picture using Instant Camera, the outside natural light from the scene we aim at enters the camera lens for a brief period. This light chemically reacts with the sensitive silver-halide crystals packed together very closely on the individual film. The crystals absorb photons, coming through the lens. Different colors like blue, red, yellow, etc. naturally have different wavelengths. Different wavelengths have different energy so they react differently with the film. Thus, a record of the light is left. Later when the ink is spread over this film, the final image is generated after a chemical reaction.

Motors, Gears, and Roller mechanisms to apply Ink and process

Figure 3 is the side view of an Instant camera with the photo coming out from the top and the lens on the right. I have only shown the internal components in this drawing, to better explain the mechanism without confusion.

1. Once the photo film is exposed to the light, a red lever shaped like a claw (marked in red) slides for about half an inch along the length of the camera and pushes the first photo film from the stack (marked in yellow) linearly.
2. Between the photo film stack and the rollers marked in brown, the frame of the camera (marked in light blue) has a horizontal protrusion and is in contact with the photo film. This helps in squeezing the ink from the solution pod that comes with each photo film and spreading it. It is because of the ink solution pod attached to one end of each photo film, that they look like yellow spoons in my drawing.
3. The pair of rollers with the one on the right being powered, helps in evenly spreading the ink on the film by applying pressure.
4. Finally, the photo film exits through the slot on the Instant Camera.
5. In order to create the colors in an image, the film also employs dyes with three different pigments: cyan, magenta, and yellow. When the ink is applied and spread over the exposed photo film, they react with crystals and other layers in the photo film to generate an image.

Question of the week

How do you think a Smartphone camera works? Let’s look at this next week! Reply with your thoughts, and would love to have a discussion with you.

Blog posts

My blog post S2E7 exploring Instant camera is out! It has additional photos, videos and a more detailed explanation. So I would highly recommend reading the blog post to get a complete understanding of the same. Happy learning!

Also, by replying to this email, let me know if you’d like to read about a specific gadget/device. And I can write about it.

Gadget of the week

Generally, I share software or a hardware gadget/app every week that’s new in the market. But once in a while, I’m sharing products I use. So here we go. This is my daily calendar that has a positive quote every day.

Thank you for reading!

Have a nice rest of the week, and take care!
Until next Wednesday,
Chendur