Kodak Portra 400 will not let you down. Without sounding too snobbish ("oooh I only shoot Portra 400 cos it's the best"), I hope to keep my review as honest as possible because of the cult following of this film stock. Insofar, the colouration, grain, versatility, and dynamic range across 120 and 35mm formats are spectacular.
Portra 400 is by far the most versatile film stock I have shot. I feel with most other film stocks, they have a temperament which begs some kind of log keeping or shooting diary to document how film reacts under different conditions. However, my notes for Portra 400 is surprisingly short simply because it does well in most conditions. When it's under exposed, the muddiness is warm and consistent and not too off putting. Not like Fuji Superia Premium 400 where shadows tend to be a little to greenish when underexposed. On the other hand, when overexposed, the colours don't get washed out but it becomes more airy and crisp. I usually overexpose Portra 400 by 1 stop (ISO 200) because it handles saturation so well. But with other film stocks like Portra 160 or Kodak Ultramax 400, I will only go as far as a 2/3 stops overexposure because of desaturation.
Grain and Versatility
90% of the time I shoot Portra 400 overexposed by 1 stop to also clean up some of the noise and also for crispier and less in-your-face colours. I do this more for a lighter look when I don't want "film" to be the ultimate goal but instead let the pictures to speak for themselves. In the rare occasion where I shoot at box speed, I do this just to achieve that "film" noir look - slightly more grain, underexposed shadows, less-than-precise metering. But given the cost of Portra 400, for the latter purpose I tend to just use the other cheaper filmstocks like Kodak Gold 200 or Fuji C200. Nevertheless, Portra 400 at box speed is still very decent and you don't get too much noise issues.
Very balanced and just a tad towards the warmer side depending on your lens. Portra 400 definitely embodies the Kodak yellow glow. Amidst the fine balance, you get a very luscious yellow that screams Kodak. Blues are not too deep, usually pale and accommodating. When well exposed, cowgrass tends to be greenish yellow and not overly saturated. When underexposed, greens tend to be a strong blue, which is why I shoot at ISO 200 most of the time because I personally don't like too overly saturated greens in my photos. This is such a step beyond Fuji C200 or Industrial 400 where I find the greens too strong - especially in Singapore. Because of the calm blues and warmer tones, I really enjoy shooting Portra 400 near the seas during sunset or mid-day when I'm near colourful subjects.
Resolution is factor of 3 things - the film stock, your lens' resolving capability, and your scanner. I have put Portra 400 through thick and thin and I can say it is the best film for scanning in high resolution (64 base on 35mm format) if you have a lens and scanner that can produce this detail. Definitely excessive for film because most mid-range film lenses don't reproduce that kind of clarity. But if you absolutely need this kind of resolution and you have the lens for it, as well as an understanding and nice lab that's willing to go out of the way to do a 64 base scan for you, such as grainsandsuch, erhm erhm *insert shameless publicity*, it's doable. Personally, I scan all my pictures at mid-range, 16 base because it's enough for most purposes. But I got cheeky once and decided to give my Portra 400 roll some extra 64 base TLC. Not disappointed at all, especially when you want to crop for printing or social media.
Sidetrack: Just a disclaimer tho, not all high res scans turn out well. I once had a customer who asked me to re-scan 64 base for a Fuji Disposable camera after scanning it at 16 base. I advised against this because of the disposable's plastic lens resolving capability and the film quality. The re-scans turned out more pixelated and grainy because there was nothing more to the picture other than the grain of the film itself! Customer never came back.
Portra 400 is highly versatile and reproduces colour very well. If you are a professional shooter and colour accuracy matters to you or if you are a serious amateur looking for something balanced to play with and a lower risk of mistakes, Portra 400 is for you because of its versatility and colour stability. If you are looking for that grainy and distinctive film-look, you can save some money and go for the cheaper Kodak and Fuji options.
If you like the way I scan, show some support by sending me your film in the link above!