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Michael Scarpitti's Revised Paterson Data

Paterson developers are superlative products and are especially valuable, if not indispensable, for the miniature worker. The Paterson developers are the brainchildren of Geoffrey Crawley, editor of the British Journal of Photography for many years. His researches into the inter-relationship of grain, speed, and sharpness, performed in the late 1950's and early 1960's, led him to design several developers that more fully and successfully exploited the potential of the 35mm black-and-white film format. Paterson developers and chemistry are marketed by Paterson in Britain and are again available in the US after several decades of absence.

Paterson developers are specialized products, not general-purpose do-everything developers, and as such they can provide superlative performance to the critical worker when handled properly. The sharpness of all Paterson developers is particularly advantageous to miniature workers who demand the ultimate quality from their negatives.


Among the first of the developers was Acutol, still the flagship of the Paterson line. Several other Crawley-designed Paterson developers have come and gone, but Acutol remains popular. It is designed to work best on conventional films of moderate speed, such as Kodak Plus-X, Ilford Pan-F and FP4 Plus, etc., but Acutol has been found to work well even with high-speed films such as HP5 Plus, when development is kept moderate. Unlike other acutance developers, Acutol does not compress mid-tones.


FX-39 was introduced to suit the tabular-grained films such as the Kodak T-Max and Ilford Delta ranges, which respond differently to most developers than conventional films do. Unlike other acutance developers, FX39 does not compress mid-tones.


Aculux-2, a revised version of Aculux, is the fine-grain entrant in the line, and is suitable for all film types, both conventional and tabular-grained types.


FX 50 is a new type of developer, which Paterson claims produces negatives with the fine grain and tonal qualities of Aculux together with the definition normally associated with acutance developers such as FX-39.

Important note on technique:

The developing times presented here are for the perfectionist who wishes to achieve the very finest results from 35mm film negatives. The way to obtain the finest grain and highest sharpness is simply to develop the film for the shortest time possible, and to use a slightly higher-contrast paper (#3) as 'normal'. Condenser enlargers provide more contrast in the projected image than do diffusion enlargers. Variable contrast heads and color heads are typically diffusion types, and thus produce less contrast than condensers.

The use of the condenser type of head, though, will allow even less development to be given to the negative, further improving the sharpness and fineness of grain. So, the best results possible from 35mm film are achieved using #3 paper and condenser enlarging.

The times and dilutions recommended by Paterson have been found by the author to be excessive for condenser enlargers and 35mm film. The times and dilutions given here have been determined to provide approximately correct contrast for #3 paper and condenser enlarging with the author's 35mm equipment. Instead of 1+9 as the basic dilution, the author recommends 1+14. Comments and corrections are welcomed!

-- Michael Scarpitti

Paterson Film Developers ˆ Times for 35mm film using condenser enlargers*

The following are suggested times which may need to be modified to suit your own enlarging equipment. Agitation during development should be standardised at two inversion once per minute. Dilute 1+14 unless otherwise noted.

*Times given below are for 35mm work. For roll or sheet film, extend times approximately 20%.

Bold entries are verified. Non-bold entries are extrapolated from Paterson data.

Developer Aculux 2 Acutol FX-39
Film 1 + 14 1 + 14 1 + 14
Acupan 200 6 3.5 5
Acupan 800 12 NR 10
Agfapan APX 100 8 8 7.5
Agfapan APX 400 9 10 9
Fuji Neopan 100 Acros 9 8 (1+15) 9 (1+19)
Fuji Neopan 400, EI 400 NR 8 8 (1+17)
Fuji Neopan 400, EI 160 8 NR NR
Fuji Neopan 1600, EI 400 8.5 NR NR
Fuji Neopan 1600, EI 800 NR 8 (1+16.5) 8 (1+19)
Ilford Pan F Plus NR 9 (1+21) NR
Ilford FP4 Plus 7 8 (1+16.5) 8 (1+19)
Ilford HP5 Plus EI 400 NR 8 (1+15) 7.5 (1+17)
Ilford HP5 Plus EI 200 9 (1+17) NR NR
Ilford 100 Delta pro 8 7 8 (1+19)
Ilford 400 Delta pro 8 8 8
Ilford 3200 Delta pro, EI 500 10 NR NR
Ilford 3200 Delta pro, EI 800 NR 10 10
Ilford SFX 7 8.5 6.5
Jessop Pan 100 8 10 6
Jessop Pan 400 10 NR 10
Kodak Plus X Pan 6 7 6.5
Kodak Tri-X Pan 8 8.5 7.5
Kodak T-Max 100 9 8 7.5
Kodak T-Max 400 9 9 8
Kodak T-Max 3200, EI 1000 NR NR 7.5
Kodak T-max 3200, EI 500 8 NR NR
Kodak H/S Infra-red 10 9 10
Kodak Tech Pan NR NR 7 (1+19)
Phototec 100 7 5.5 6
Phototec 400 10 NR 10

Paterson black-and-white Film Developers

The dilution is 1+14 for each developer unless otherwise specified.

Characteristic FX-39 Aculux 2 Acutol
Finest possible grain-Yes-
Ultimate sharpnessYes (Tabular-grain films)-Yes (Conventional films)
Good PictorialYesYesYes
Best possible tonal rangeYes (Tabular-grain films)YesYes
Maximum shadow/highlight detailYes (Tabular-grain films)-Yes
Film speed adjustmentYes*(slight)-Yes
General purpose fine grain developerYes-Yes
Designed for advanced technology filmsYesYes-
High contrast films/subjects--Yes (Dilution change required)

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