ADOXCHS 100 II

ADOX CHS 100 II is an ISO 100 black-and-white negative film from ADOX Fotowerke in Bad Saarow, Germany. Its emulsion is orthopanchromatic, coated in a single layer on a clear polyester (PET) base, and ADOX pitches it as a classic-looking film with “classical grain” [1]. It is sold in 35 mm, 120 and sheet film [1].

Look and color

CHS 100 II turns colors into grays according to a sensitization that differs from most modern films, and the sources disagree on what that means for skies:

• Strong blue response. The datasheet curve is highest in the violet and blue [1]. The reviewer at 35mmc reports “much greater blue sensitivity” than on panchromatic films, and expects a yellow filter to have a stronger effect [2].
• Little deep red. The curve is cut off sharply near 660 nm [1]. Fotoimpex says this gives “deeper skies with standing-out clouds” [3], a retailer’s commercial text.
• A contradiction we do not settle. Strong blue sensitivity would usually make a sky lighter, while the retailer promises deeper skies. The dip near 495 nm in the curve could explain both: pure blues render light, blue-green tones of a low sky render darker. On our test RAW files the style made a sky 5.3 L* lighter and skin 5.1 L* darker than the base render [7].
• Faces and clouds. ADOX says the film separates lips and face, clouds and sky, and water and land better than modern films [1]. Fotoimpex adds “balanced tonal reproduction in portraiture” [3].

Tonality

• Shoulder and latitude. ADOX describes “a distinct shoulder in the highlights” that prevents them from “blowing out”, and a very large exposure latitude [1]. The datasheet has no characteristic curve, so this rests on the text alone.
• Contrast is set by development. The published times target a beta of 0.65, a medium contrast. Sheet film needs about 10 % less time to reach it [1].
• Open shadows, or dull? Fotoimpex describes “delicate, soft, airy images with open shadows, creamy highlights and a smooth tonal transition” [3]. The reviewer at 35mmc found the film “duller” than FP4 Plus, with midtones less separated from highlights and shadows, better in strong sunlight than in flat light [2]. In 2013, Bruce Robbins saw “decent shadow detail” and “a good range of gutsy-looking tones” at box speed in Rodinal 1+50 [5]. The maker’s account and the reviews do not fully agree.
• Long exposures. No correction up to 1 s; from 2 s, 1.5x to 3x (3 s at 2 s, up to 45 s at 15 s) [1].

Grain and sharpness

ADOX publishes no RMS granularity and no print grain index, and no resolving power figure, so grain cannot be compared with other datasheets in a table. The sources describe it in words:

• The datasheet says “classical grain” [1]. Fotoimpex says the film has more grain than a standard ISO 100 film [3].
• At 35mmc, scans developed in Rodinal showed “more intrusive grain” than FP4 Plus. The reviewer described the difference as one of micro-contrast rather than size and suspected the developer [2].
• In 2013, Robbins called the grain “reasonable”, comparable to Agfa APX or HP5 Plus rated at ISO 200, with good sharpness [5].
• The 35 mm and 120 versions have two anti-halation layers: one between emulsion and base, and a tinted backside layer that also fights light piping and curl [1]. Retailers say this helps sharpness [6].
• Handling. PET can guide light into the cartridge, so ADOX says to protect the leader from bright light, and 120 rolls can spring open once the tape is cut [1]. Robbins saw light piping once despite the tinted layer [5].

Spectral sensitivity

The datasheet plots one curve from 400 nm to roughly 660 nm, with no vertical scale and no stated light source. It shows a high level in the violet and blue, a marked dip near 495 nm, a plateau from about 575 to 630 nm and a steep cut-off beyond 640 nm [1]. In practice, saturated blues render light, reds and oranges render dark, and the cut-off means little deep red is recorded. Because the axis is unlabeled, the exact weight between blue and red depends on assumptions we describe with the style [7].

Names, status and history

• CHS 100 and CHS 100 II. 35mmc says the original CHS 100 ran into problems that led to its discontinuation, and that CHS 100 II was released in 2013 [2]. Wikipedia describes it as introduced in 2013 “as a modern coating on a polyester base”, sold out by 2016 and not reintroduced until 2018 [4]. The Online Darkroom’s first look is dated October 2013 [5].
• The classic ADOX film. Wikipedia links the ADOX name to a 1950s orthopanchromatic film, sold as Efke KB 100 until 2012 [4]. We found no source that says CHS 100 II has the same emulsion as that film, so we do not claim it.
• Status. Wikipedia lists CHS 100 II in the current range, in 135, 120 and sheet film [4]. On September 30, 2026, the Fotoimpex 35 mm page showed it sold out for mail order [3] and CineStill listed the 35 mm roll as out of stock [6]: stock varies.
• Datasheet. The one we used is dated July 11, 2024. The original ADOX link returned an error, so it is cited through a copy hosted by Fotoimpex [1].
• Reversal. ADOX says the film, sheet film included, can be reversal processed [1].