Darkroom Chemical Guide
Reference times, dilutions, and temperatures for common darkroom developers, stop baths, and fixers. All times at 20°C / 68°F unless noted.
Developers
Stop Bath
Fixer
Paper Dev
Kodak D-76
Film Developer — Fine Grain Standard
1:1
Stock dilution
9–11 min
HP5 @ 400
20°C
Standard temp
One-shot
Use mode
Versatile, widely available, affordable. Slight compensation at highlights. Use stock for finer grain, 1:1 for more exposure latitude. Ilford ID-11 is identical.
Kodak HC-110
Film Developer — High Contrast, Fast
1:31 (B)
Common dilution
5–8 min
HP5 @ 400
20°C
Standard temp
One-shot
Use mode
Syrup concentrate — very economical. Dilution B (1+31) is most common. Higher contrast than D-76. Great for push processing and orthographic film.
Ilford Ilfosol 3
Film Developer — Sharpness-Oriented
1:9
Standard dilution
7.5 min
HP5 @ 400
20°C
Standard temp
One-shot
Use mode
Good acutance (edge sharpness). Slight grain enhancement. Excellent for medium and large format. Works well with slow films like Delta 100.
Rodinal (R09 / Stand)
Film Developer — High Acutance, Long Shelf Life
1:50 / 1:100
Typical dilution
60 min stand
Stand develop
20°C
Standard temp
One-shot
Use mode
Legendary formula, nearly infinite shelf life once diluted only fresh. Stand development (1:100, 1hr, 2 inversions only) gives incredible sharpness and local area compensation.
Acetic Acid Stop Bath
Stop Bath — Standard
1:19
Dilution (28% AA)
10–30 sec
Film time
~pH 4
Working pH
Reusable
Use mode
Immediately halts development. Use indicator stop bath (turns purple when exhausted). Agitate continuously. For prints: 30–60 seconds minimum.
Water Stop Bath
Stop Bath — Alkaline Alternative
Undiluted
Running water
60 sec
Min rinse time
20°C
Water temp
Free
Cost
Gentler on film/paper but less effective at stopping development. Use when you want to continue development slightly during the rinse (zone system tricks). Multiple changes of water recommended.
Kodak Rapid Fixer
Fixer — Ammonium Thiosulfate
1:4 film
Film dilution
2–5 min
Film time
1:7 paper
Paper dilution
Reusable
Use mode
Ammonium thiosulfate works faster than sodium. Fix until film is clear + equal time again (2× clearing time rule). Test clearing time: place an undeveloped film scrap in working fixer and time until clear.
Ilford Rapid Fixer
Fixer — Modern Rapid Formula
1:4 film
Film dilution
2–5 min
Film time
1:9 paper
Paper dilution
Reusable
Use mode
Reliable and widely used. Capacity: ~25 rolls of 35mm per liter at working strength. Discard when it takes more than 2× the original clearing time.
Ilford Multigrade Dev
Paper Developer — Universal
1:9
Dilution
60–90 sec
Dev time
20°C
Temp
Reusable
Use mode
Clean, neutral tone. Works with all Ilford VC papers. Develop until full shadow detail appears, then give 30 more seconds. Exhausted solution yellows highlights.
Kodak Dektol
Paper Developer — Warm/High Contrast
1:2
Dilution
60–90 sec
Dev time
20°C
Temp
Reusable
Use mode
Classic cool tone with high contrast. The industry standard paper developer for decades. Diluting 1:3 softens contrast and gives slightly warmer tones.