How to Set Aspect Ratio in MidJourney？

The aspect ratio (--ar) is one of the most important parameters in MidJourney, allowing you to define the proportions of the generated image. This is especially useful for different types of compositions, such as square portraits, wide landscapes, or tall vertical images.

Here’s a step-by-step guide to setting the aspect ratio in MidJourney:

1. What is Aspect Ratio?

Aspect ratio defines the proportional relationship between an image’s width and height. It is expressed as width:height.

  • Common Aspect Ratios:
    • 1:1 – Square images, good for Instagram or symmetrical compositions.
    • 16:9 – Widescreen, great for cinematic landscapes or wide scenes.
    • 4:3 – Standard photography ratio, balanced for most scenes.
    • 2:3 or 3:4 – Portrait photography, ideal for vertical images.
    • 9:16 – Tall vertical, great for mobile screens.

2. How to Add Aspect Ratio in a Prompt

You can specify the aspect ratio by using the --ar parameter in your prompt.

Syntax:

  • Add --ar [width]:[height] at the end of your prompt.
  • Example: --ar 16:9 for widescreen or --ar 3:4 for vertical.

Prompt Example:

a breathtaking sunset over a mountain range, cinematic lighting, vibrant colors --ar 16:9

3. When to Use Different Aspect Ratios

Here are some common scenarios and the recommended aspect ratios:

  1. Square (1:1):
    • Use for: Instagram posts, minimalist compositions, or symmetrical designs.
    • Example:
      a minimalistic geometric pattern, symmetrical design, vibrant colors --ar 1:1
  2. Widescreen (16:9):
    • Use for: Cinematic landscapes, epic scenes, or group portraits.
    • Example:
      a vast desert with rolling dunes under a dramatic sky, cinematic style --ar 16:9
  3. Portrait (2:3 or 3:4):
    • Use for: Character portraits, book covers, or focused subjects.
    • Example:
      a detailed portrait of a medieval knight in armor, dramatic lighting, ultra-realistic --ar 3:4
  4. Tall Vertical (9:16):
    • Use for: Mobile wallpapers, vertical banners, or elongated designs.
    • Example:
      a futuristic skyscraper piercing the clouds, glowing neon lights, cyberpunk style --ar 9:16
  5. Classic Photography (4:3):
    • Use for: Balanced compositions, street photography, or documentary-style images.
    • Example:
      a bustling marketplace at dawn, natural light, vibrant colors, realistic detail --ar 4:3

4. Default Aspect Ratio

  • If you don’t include the --ar parameter, MidJourney defaults to a 1:1 (square) aspect ratio.
  • To create other shapes, always specify the desired --ar.

5. Combining --ar with Other Parameters

You can combine the aspect ratio with other parameters for better results:

  • Quality (--q): Adjust image quality.
    • Example: --q 2
  • Style (--style): Control the stylization of the image.
    • Example: --style 250
  • Chaos (--chaos): Add randomness to your results.
    • Example: --chaos 20

Example Prompt Combining Parameters:

a lush rainforest with a hidden waterfall, sunlight streaming through the canopy, photorealistic, cinematic, --ar 16:9 --q 2 --style 500

6. Experimenting with Aspect Ratios

It’s always a good idea to test different aspect ratios to find the one that best suits your composition. For example:

  • A wide ratio like 16:9 works great for landscapes.
  • A tall ratio like 9:16 adds drama and verticality to architectural scenes.
  • A square ratio like 1:1 keeps the composition clean and simple.

Tips for Best Results:

  1. Match the Aspect Ratio to Your Subject:
    • Wide ratios for scenery, tall ratios for vertical subjects like trees or buildings.
  2. Keep Your Prompts Detailed:
    • Pair your aspect ratio with keywords like “cinematic,” “portrait,” or “dynamic composition” for better framing.
  3. Iterate and Refine:
    • Test multiple aspect ratios to see which one delivers the most satisfying result for your idea.

Final Thoughts

Aspect ratios are a powerful tool in MidJourney that allow you to control the framing and layout of your generated images. By understanding how to use --ar, you can create visuals tailored to your specific needs, whether they are for cinematic scenes, character portraits, or dynamic storytelling. Experiment, refine, and explore the possibilities that aspect ratios unlock!