Ilford Delta 400 is a medium-speed, fine-grained mild-contrast black and white film. This emulsion uses a relatively modern development in photochemistry — T-Grain — which was first implemented in consumer products in the 1980s. This ingenious method of growing photosensitive crystals is behind Delta 400’s silky-smooth grey tones — contrasting the chunky grain of HP5+, Tri-X, and other classic film recipes.
In this review of Delta 400, I’ll discuss its grain structure, compare it to non-T-Grain films, and cover its key attributes in detail with sample scans: resolution and dynamic range. I will also share my scanning workflow and examine how this film responds to post-production edits.
What is T-Grain film?
T-Grain is a product of shaping film’s photosensitive crystals into tabular structures, which makes them more efficient at absorbing light.
If you look at the surface of photographic film under a microscope, you’ll notice a scattering of light-sensitive crystals of various sizes. Those crystals are designed to absorb light particles (photons). But not all light gets absorbed; instead, some rays pass through the space between the crystals. Plus, it takes a few photons to activate the reaction, so some smaller specs never get triggered until they receive ample radiation.
Larger nets catch more fish. By the same account, larger crystals “catch” more photons on their expanded surface. This means they don’t need as intense or prolonged exposure to light as the smaller crystals.
This is why faster, more sensitive films require larger grains (crystals) to work in low-light conditions.
Up until the 1980s, those crystals resembled grains of sand; they were small and 3-dimensional. But in 1982, Kodak released Kodacolor VR 1000, which was the fastest-ISO film ever produced at the time. And the reason it was able to achieve such sensitivity was the new “tabular” (tablet-like, flat) shape of the film grain crystals.
The flatter, 2-dimensional tabular grain (T-Grain) absorbs light more efficiently by preventing light scattering. Whereas the 3-dimensional grains have several surfaces pointing at various angles (which sometimes causes the photons to bounce off and affect the nearby crystals), T-Grain films form flat surfaces that face the light at a right angle and avoid light scattering.
This improved crystal efficiency lets manufacturers create faster films with finer grain. However, closer attention must be paid to development times for those who process film at home.
Above: Ilford HP5+ vs Ilford Delta 400 film grain comparison. This is a 6x crop of 35mm film, scanned with PrimeFilm XAs at 34MP. You may or may not notice the difference in grain size and shape — depending on the screen you’re viewing this on and where you look. The most obvious difference can be seen in the top half of the image.
Delta 400 grain and resolution.
You may or may not have noticed the difference T-Grain makes for Ilford’s Delta 400 when compared against the “traditional” HP5+ emulsion (above). Indeed, on smaller screens, not much can be discerned. But in print, this can be significant.
Looking at the scans, I’ve noticed less noise in the highlights (sky region) with Delta film as compared to HP5+, giving it an overall smoother look. The T-Grain doesn’t appear as sharp, however, so the details don’t look any more legible in mid-tones with the newer tech (although they probably could after some post-processing). Finally, in the shadows, Delta 400 performs significantly better, with fewer details disappearing into the blackness and less overall “fuzziness.”
Without cropping, photos shot on 35mm Ilford Delta 400 may even get confused with fully digital photographs as there’s virtually no visible grain. Although under-exposed regions may still reveal its distinctly-analogue character.
Delta 400 dynamic range.
If you look closely at the graph, you’ll notice that the toe has a sharper bend than the shoulder which means less latitude for mistakes in the shadows and more in the highlights. In practice, this is exactly how this film renders — at least when developed at box-speed in Ilford DD-X.
This uneven contrast profile is similar to that of Fujifilm Acros II, which retains plenty of detail in the highlights but loses shadow information fairly quickly. However, Delta 400 shows more grain in the shadows than Acros and thus doesn’t look appealing when under-exposed.
For best results with Delta 400, I would try to measure my exposures precisely and err on the side of over-exposure.
If you find that Delta 400 isn’t giving you strong-enough contrast with your developer, you may increase it in post-production, although I recommend using optics to do that instead — more on that below.
Scanning and post-processing Delta 400.
Delta 400 responds well to digital contrast manipulation. Its grain will appear larger with contrast increases; however, the scans don’t seem to lose detail or create harsh-looking grain — which could happen with other films, i.e.: Fujifilm Acros (a T-Grain film) and Kodak Tri-X (a classic-grain film). Delta 400’s grain can resemble HP5+ after a medium contrast gain.
If you decide that your scan needs adjustment, I recommend you pay particular attention to your deep shadows, as they tend to become unnaturally black quickly.
However, given that Delta 400 costs about 20% more than HP5+, I would try to take advantage of this film’s smooth, fine grain not replicable with any traditional emulsion. To do so, I’d choose a high-contrast lens and put on a yellow filter to get stronger contrast optically while keeping my post-processing to a minimum.
How much does Ilford Delta 400 cost, and where to buy it.
Film prices have been going up consistently during the past four years. Like other products, these costs follow monetary inflation, raw material markets, and the photograhers’ demand. The tumulous 2020s brought us supply chain disruptions, record inflation, and significant growth of interest in film photography. However, the most significant increases in Ilford film prices happened in 2018-2019, with only slight bumps in cost recently.
If you’re interested in film prices and would like to stay on top of them, the best way is to subscribe to the free semi-annual reports on film costs. I do all the hard work surveying a curated variety of film stores across the world on this and many other film stocks.
Finding Ilford film online isn’t difficult — this article alone lists a few places that can sell you Delta 400 today. It is certainly not rare; offline, this film is usually sold at most photo retailers, although HP5+ is probably an even more available choice.
❤ By the way: Please consider making your Ilford Delta 400 film purchase using this link so that this website may get a small percentage of that sale — at no extra charge for you — thanks!