Potential Film Developing Problems

• Negatives too "thin" or transparent - two possible reason for this are: a) negatives received insufficient exposure in camera, and/or b) negatives didn't receive enough development (developer time too short, developer temperature too cool, developer excessively diluted with water). These negatives will be difficult or impossible to print well.
• Negatives too "dense" or dark - two possible reasons for this are: a) negatives received too much exposure in camera, and/or b) negatives received too much development (developing time too long, developer temperature too warm, developer not sufficiently diluted with water). However you may be able to get a good print from dense negatives.
• Clear Film, no frame numbers - caused by non-development of the film, most often caused by accidentally using fixer before developer. Label your chemicals to reduce confusion.
• Clear Film, frame numbers visible - no exposure in camera. Look for mistakes in loading film in camera or camera mechanical problems. Check to see if your rewind knob turns (if you have one) when advancing film.
• Black Film Overall - film was exposed to light outside of the camera.
• Black Streaks on Film - light leak in camera, film canister, or during developing steps.
• Excess edge density in sprocket hole pattern - dunk and pump agitation or other non-turbulent developer agitation. With 4-reel steel tanks, load only the bottom 3 reels with film, leaving the top reel empty for larger airspace to achieve better agitation. (See George Post, "Shake it Up", p 20, Darkroom Photography magazine,  March/April 1986 for an in-depth comparison of different film agitation techniques in both plastic and metal tanks.)
• Excess edge density - rotation of tank instead of inversion during developing, stainless reels especially prone.
• Goose-bump appearance (in miniature) on film surface, print has an odd "grainy" appearance - reticulation caused by a sudden, large temperature change while processing.
• "Lightning bolts" exposed onto film - static electricity discharge due to rapid film handling (film advanced too quickly, bulk loader rolling speed, etc). Most prevalent in dry winter conditions.
• Mottling - caused by bromide drag resulting from insufficient agitation.
• Lengthwise streaking - caused by rotational agitation, not inversion.
• Scratches - if long and straight, particle of dirt on felt or in camera. Bulk loaders especially prone when cassettes are old. If scratches are short and not perfectly straight, probably caused by rough squeegeeing (dirt or carelessness) or sponging of wet film, or dragging film on rough surface. Scratches through the emulsion will print dark, while scratches on the non-emulsion (shiny) side will print light.
• Pinholes (small clear spots) in negative, produces round dark spots in print - Air bubbles or "air bells" clinging to film in developer, caused by dissolved air in water supply. More prevalent in winter. Try a water pre-soak before developer and add a couple of drops of Photo Flo in developer.
• Density variations in negative, shaped like drips - fill marks from developer pouring into the canister too slowly. Tip canister for rapid fill, and/or use a water presoak.
• Opaque blotches on film, often an ugly brown or bluish color - adjacent wraps of film touching on reel. Fairly common occurrence with beginning darkroom workers.
• Crescent creases on negative print as white "moons" in picture - rough film handling before developing bends film base and creates dense crescent-shaped artifacts.
• Fairly abrupt division between dense and thin halves of a roll of film along its length - insufficient quantity of developer to keep the film submerged at all times. Don't confuse the film developing issue with flash synchronization speed errors which could give a similar appearance.