Hand a wedding photographer both Portra 400 and Fuji 400H and ask which one they'd load for the ceremony, and you'll get a real answer rather than a shrug — the two stocks aren't interchangeable options in the same speed class so much as two different bets about what a portrait should look like.
Portra 400's color rendering isn't warm by accident or by a vague overall bias. Kodak engineered its red and yellow response specifically around the 590–620nm band — the range where human skin pigmentation actually sits, regardless of the individual's skin tone. Tuning the film's response tightly around that specific band is what produces skin that reads as warm and flattering rather than clinically neutral: the film is doing targeted work in exactly the wavelength range a face occupies, not applying a general warm cast across the whole image.
Fuji 400H, now discontinued but still widely shot from remaining stock, took the opposite philosophical direction. Where Portra warms, 400H cools — pushing greens cooler and lifting highlights into a soft, almost pastel range rather than concentrating its tuning on the skin-tone band the way Portra does. Skin under 400H doesn't get Portra's warm treatment; it renders a touch cooler and cleaner, with the airy, luminous quality that made the stock a wedding-photography staple in its own right — particularly suited to bright daylight and high-key work, where holding detail in a white dress under harsh sun mattered more than concentrating warmth in faces.
Why This Isn't a White-Balance Difference
Neither of these outcomes is a global color-temperature shift you could reproduce by nudging a white balance slider on a scan. Portra's targeted response in the 590–620nm band affects how strongly that specific range of wavelengths gets rendered relative to everything else in the frame — it's a band-specific behavior baked into the emulsion, not a uniform tint over the whole image. Shifting a scan's white balance moves everything together and can't selectively recreate what a different stock's dye chemistry does to one wavelength range and not another. That's why photographers describe switching between these two stocks as changing the character of skin and light, not just the temperature — because what's actually different is where in the visible spectrum each film concentrates its attention, not a single global cast you could dial in afterward.
Neither Choice Is a Compromise
Portra's tight focus on the skin-tone band makes it the more forgiving stock for mixed skin tones and less-than-ideal light, since it's solving specifically for the problem a portrait photographer cares about most. Fuji 400H's broader, cooler, airier approach made it the stock of choice for photographers who wanted a lighter overall palette and were willing to trade some of Portra's skin-tone precision for that mood. Both were built to serve the same category of work — natural-light portraits and weddings — and arrived at genuinely different answers, which is exactly why photographers who've shot both tend to have a strong, specific preference rather than treating the two as roughly the same film at two different price points.