A breathtaking portrait of an enchanting mermaid with flowing, luxurious hair, surrounded by a swarm of delicate goldfish against a vibrant backdrop of diverse marine life. The scene is illuminated softly, as the sunlight struggles to penetrate the depths, creating a mesmerizing cinematic effect. Captured in rich detail with a 35mm lens at F/2.8, the composition features a subtle vignette and 4k resolution. The spotlight casts an elegant, intricate glow over the scene, highlighting the mermaid's ornate scales and ethereal beauty, while the underwater ambiance is enhanced by the cinematic lighting, presenting an insanely detailed and exquisite underwater fantasy realm.