09.16. | The Decisive Moment, Censored: How to Fake the Bresson Look with Gemini AI

Let's use the tools of the digital age to summon the spirit of Henri Cartier-Bresson, the godfather of street photography. (If you'd like to know more about him, you can read the post from our previous session here.) Bresson—who reportedly dismissed the idea of being called the greatest photographer of the 20th century with a rather blunt “bullshit”—stood out not only for the famous “decisive moment” but for his extraordinary instinct for composition.

Let's start with the most important thing: equipment.

1. Bresson Commando: Gear and Philosophy

The Camera, or the Anarchist Arsenal

HCB famously worked with a 35 mm Leica rangefinder and a 50 mm lens.

Our Setup: Don't worry if your budget doesn't stretch to a Leica. On a digital Micro Four Thirds camera such as an Olympus | OM System, a 25 mm lens gives roughly the same angle of view as a 50 mm lens on full frame. And if all you have is the phone Bresson never had—but you love using it—use that and apply his principles.

Film and Colour: Black and white, always. Kodak Tri-X rated at ISO 400 was a classic choice. With a digital camera, switch on a monochrome preview so you can already judge light and shadow in the viewfinder.

The Sacred Triangle: Aperture controls how much light enters, while a shutter speed around 1/125 second is a useful starting point for this kind of street work.

Shallow Depth of Field Is Banned: Forget F1.5 for this exercise. If the depth of field is too shallow, the layers disappear—and the people in the background matter. Here we're not only looking for emotion; we're looking for form and geometry.

The Sin of Flash: Don't use it. Cartier-Bresson famously disliked flash and felt it disrupted the natural moment.

2. The Decisive Composition, or Geometric Compulsion

For Bresson, form, geometry and structure were central. You have to learn to look like an artist or painter who has spent years studying visual relationships.

Leading Lines: The easiest place to begin. Look for lines that guide the eye straight towards your subject.

Rule of Thirds: Divide the frame and place the subject near one of the intersections. Simple, useful, done.

Frame within a Frame: Use architecture or other elements to frame your subject inside the picture. Bresson did this beautifully.

Rule of Odds: Embrace a little visual strangeness. Look for groups of three or five, or for one person who breaks the pattern—for example, a moving figure between two static groups.

Juxtaposition: A fashionable word for meaningful contrast. Youth beside age, movement beside stillness, elegance beside decay—the relationship creates the image.

Golden Ratio: The difficult one. Don't worry if you don't consciously see it while shooting. You may only discover later, looking through the images, that your composition accidentally made you look like a genius.

The Bresson Paradox: Bresson was famous for preferring to compose in-camera rather than crop afterwards. Yet one of his best-known photographs—the man leaping over a puddle behind the Gare Saint-Lazare—did require cropping because his viewpoint was physically constrained. A photographer's life is full of irony.

3. The Gemini “Nano Banana” Function: A Shortcut to Geometry

But what if we simply asked AI for a perfect “Bresson”?

The Theory of Gemini's Nano Banana Function

Google Gemini can perform powerful image manipulation and generation. From our point of view, it's almost like waving a magic wand over some of the effort that traditional photography demands.

After signing in to Gemini, you can use it in several ways relevant to our experiment:

Instant Style Transformation: Upload an image and describe the high-contrast, geometric, documentary black-and-white character you want. Rather than relying only on a famous artist's name, describe the actual visual features: monochrome, layered street composition, strong geometry, candid movement, natural light.

Contrast Correction: If the image isn't working, you can ask for a black-and-white, higher-contrast interpretation and use that as a visual reference for what you might later do more carefully in your own edit.

Inspiration Partner: Use AI for previsualisation. If you have an idea in your head, create a rough visual direction and send it to a client with the message: “I'm thinking along these lines.”

Generating the “Decisive Moment”: If you're tired of searching the streets for the exact choreography you imagine, AI can even generate a conceptual scene or motion study. That doesn't make it documentary photography, of course—it makes it a generated reference or artwork.

Important Notes About the Nano Banana Experiment

Watermarks and Provenance: AI tools may add visible branding or embed provenance information in generated files. Don't treat that as an inconvenience to be secretly removed; if an image is AI-generated, transparency about its origin is the better practice.

Quality Caveats: Generated images can still fall apart under close inspection or at large output sizes, while a carefully made and retouched original photograph may retain far more genuine detail. The technology is evolving quickly.

So if you choose machine generation instead of machine-like concentration, you'll still need a story about what you're trying to communicate. Our own approach is more useful: go outside, design the moment deliberately, make the photograph, then experiment with AI only as a secondary creative layer—not as a substitute for seeing.

Then we left the virtual world and went into the streets to hunt for photographs in the evening light.

The objective? One perfect image.

Forget the thousand pictures you'd delete anyway and concentrate. Black and white or colour? Your choice. If you work in colour, try lowering saturation for a softer palette. On a phone, experimenting with the black point and exposure can create a hazier, more graphic mood.

And here's the twist: don't only look for spontaneous moments now. Construct movements. Anticipate them.

Give yourself no more than five minutes to decide what you want to make from whatever is in front of you. That's not time pressure; it's creative discipline. Practise in the evening when the streets are calmer. Use the city's existing lights. On a phone, tap to expose, then drag the exposure down until the scene gains the darker, more dramatic mood you want.

If you enjoy discovering the great figures of photographic history, join our next online Zoom session on Tuesday, October 7 from 18:15. If you can't make the live time, it's still worth registering: we send the complete session by email two days later. Free registration and details are available here.

Now let's look at what our team created this week. And if you'd like to join us in Vienna on Tuesday evenings, you can read the details here. You can join at any time.

Part of the BANHALMI ecosystem

For the professional context and practical side of portrait photography, visit the BANHALMI professional website. Related art series, books and exhibitions are preserved in the BANHALMI ART archive.