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Set the Camera Lens

Goal: Choose the focal length for a shot's camera so you control field of view, depth compression, and the visual feel — from wide-angle drama to telephoto intimacy.

Lens choice is one of the most powerful creative decisions in cinematography. The focal length determines how much of the environment the camera sees, how compressed or expanded the depth of the image feels, and what emotional register the shot sits in. A wide-angle lens makes environments feel vast and characters feel exposed; a telephoto lens compresses space and pulls characters closer to the viewer, making the shot feel more intimate or claustrophobic depending on how you use it.

If you're new to camera work: think of this as the difference between the camera on the back of a phone (wide angle, sees a lot) and a pair of binoculars (telephoto, sees far away, feels compressed). Both are useful — for different things.

Steps​

  1. Open a shot. Click on the shot you want to configure in the shot list. The Shot panel opens on the right.

  2. Go to the Camera tab. In the Shot panel, click the Camera tab. This section contains all camera settings for this specific shot: lens, movement, angle, and framing.

  3. Find the Lens selector. The Lens field appears near the top of the Camera tab. It may currently show a default lens value or Not set.

  4. Understand the lens options. ACT3 AI offers the following focal lengths:

    LensFocal LengthCharacter
    Ultra-Wide12mmExtreme environment emphasis, dramatic distortion
    Wide24mmExpansive, environmental, slightly dramatic
    Normal50mmNatural, neutral, closest to human eye
    Portrait85mmFlattering, slight background compression
    Telephoto135mmStrong background compression, subject isolation
    Long Telephoto200mm+Maximum compression, surveillance feel, extreme isolation

  5. Select the lens for this shot. Click the Lens selector and choose the focal length that fits the shot's purpose. For example: an establishing wide shot of a city → 24mm. A close-up on a character's face during a tense moment → 85mm or 135mm. An action shot showing a character running through an environment → 24mm or 35mm.

  6. Understand what each lens does visually. Beyond field of view, focal length changes the relationship between subject and background:

    • Wide lenses (24mm and below): more environment visible, background feels far away, space feels large
    • Normal (50mm): balanced — subject and background feel proportionally natural
    • Telephoto (85mm+): background compresses toward subject, environment feels smaller, subject is isolated and dominant in the frame

  7. Consider how lens interacts with shot type. A close-up filmed on a 24mm lens produces a distorted, confrontational effect because the camera must be very close to the subject — the face looks slightly stretched. The same close-up on an 85mm lens, with the camera further back, produces a natural flattering look. A wide shot on a 135mm lens, with the camera far back, compresses the environment and makes a crowd look denser than it really is.

  8. Preview the change in the prompt. After selecting a lens, look at the AI Prompt Preview section below the Camera settings. The lens choice is automatically included in the generation prompt as a descriptive modifier. You can see how the lens description affects the overall prompt context before rendering.

  9. Apply the lens to this shot. Your lens selection is saved automatically. Render the shot to see the result. If the visual feel isn't right, return to the Camera tab and try a different focal length — re-rendering a single shot to compare options is a fast iteration cycle.

Tips​

  • 50mm is the closest to how the human eye sees the world — default to it when you're unsure what lens to use. It never looks wrong, even if it isn't the most dramatic choice.
  • Use 85mm to 135mm for character close-ups. These focal lengths have been used in portrait and film photography for decades because they produce natural, flattering compression without distortion.
  • Use 24mm and wider for establishing shots and action sequences where you want the audience to understand the environment. Wide lenses are disorienting when used for close-ups but feel exciting and spatial for big moments.

Next steps​