Ilford Delta 400

Delta 400 occupies a specific niche between HP5+ and the T-grain speed it shares with Kodak T-MAX 400. The tabular grain structure produces finer-looking grain than HP5+ at the same speed, but the curve is steeper. Midtones are contrastier and shadows clip more abruptly if you underexpose. It rewards accurate metering more than HP5+ does, and pays you back with cleaner highlights and better scan density when you expose correctly.

For photographers who want tight grain at 400 speed and are willing to meter carefully, Delta 400 is one of the best choices available. The 120 negative is genuinely impressive for a 400-speed stock. Compared to HP5+ in 120, the grain reads finer and the midtone transitions look more photographic than reportorial. Still-life, portrait, and documentary work in available light all benefit.

In D-76 or Ilfotec DD-X, development is predictable and the contrast builds evenly. It pushes reasonably to ISO 800 with a one-stop bump in time, though the shadow-end clipping gets more pronounced. Most photographers find box speed with good light the sweet spot rather than pushing, which is the opposite of how they tend to use HP5+.

Delta 400 is available in 35mm and 120 only. No sheet sizes, which limits its use in view camera work.

The reciprocity exponent is 1.41, which is one of the steepest values in the B&W catalog. Past one second, exposures climb significantly faster than other Ilford stocks. A 30-second meter reading becomes roughly 130 seconds at the negative instead of the 75 to 90 seconds typical for Delta 100 or HP5+. Zone Light Meter applies the 1.41 curve automatically, which is important because guessing from another stock's correction will produce underexposed long exposures.