CHS 100 II

Tonality: long, gently rising curve with generous shoulder. Highlights hold on much longer than a modern 100-speed film before blocking up; midtones are where it separates best.

Grain: cubic, clearly visible, sharp-edged rather than mushy. Not fine by modern standards — closer to the look of a 1960s emulsion than to Delta or T-Max.
Sharpness: excellent. The thin single-layer coating gives strong edge definition, which is a large part of why the grain reads as crisp rather than soft.

Red sensitivity: extended, so reds and warm skin render lighter than expected and skies go paler without a filter. A yellow or orange filter has a stronger effect here than on most panchromatic films.

Glow: highlights bloom slightly around hard light sources — a characteristic of thin classic emulsions and a large part of why people choose it.

Latitude: wide on the overexposure side, less forgiving under. Many shooters rate it at EI 50–80 to open the shadows.

Developers: Rodinal/Adonal 1+50 is the traditional pairing and emphasises the sharpness and grain. Atomal 49 or D-76/ID-11 tames the grain and gives a softer, more compact scale. XT-3 sits between.

Handling: the emulsion is softer than modern films. Wash and squeegee carefully; avoid hardening-free workflows getting warm, and expect 120 to curl.

Best suited to: landscape, architecture, still life, portraiture in soft light — subjects with long tonal ranges and time to expose carefully. Less suited to fast handheld work or scenes needing clean shadow detail at box speed.
In one line: the closest thing currently in production to what black and white film looked like before multi-layer coating.