Lesson 03 · Midjourney Mastery
Pro
~11 min read
Updated June 2026
Parameters: the dials that do the work.
Midjourney has many parameters, but a few earn their keep daily. Learn these and you control output instead of hoping for it.
01Aspect ratio (--ar)
Sets the shape: --ar 16:9 for widescreen, --ar 9:16 for vertical, --ar 1:1 for square. Set this first — it changes composition more than almost anything else, because the model frames the subject for the canvas.
02Stylize (--s) and Chaos (--c)
Stylize controls how much Midjourney imposes its own aesthetic — low for faithful-to-prompt, high for prettier-but-looser. Chaos controls how varied the four grid images are — low for consistent, high for wild divergence when you want options.
Seed (--seed) — the consistency leverA seed fixes the starting randomness. Reuse the same seed with a tweaked prompt and you get a controlled change instead of a totally different image. It is how you iterate on one idea rather than gambling each time.
Parameters go at the enda misty pine forest at dawn, cinematic photograph, soft light --ar 16:9 --s 250 --c 10
Do not stack every parameter at once. Change one, see the effect, then the next. Most images need only --ar plus maybe --s; the rest are for specific problems.
Frequently asked
Midjourney — your questions, answered
What does --ar do in Midjourney?
It sets the aspect ratio (image shape) — for example --ar 16:9 for widescreen or --ar 9:16 for vertical. Set it first because it reshapes the composition.
What is the difference between stylize and chaos?
Stylize (--s) controls how strongly Midjourney imposes its own aesthetic; chaos (--c) controls how different the four grid images are from each other.
What is a seed in Midjourney?
A seed (--seed) fixes the starting randomness so you can re-run a tweaked prompt and get a controlled change instead of a completely new image.
Which Midjourney parameters should I learn first?
Aspect ratio (--ar) and stylize (--s) cover most needs; add chaos and seed when you specifically need more variety or repeatable iteration.