Black-and-white negative film · In production

CatLABS X FILM 320

CatLABS X FILM 320 is a black-and-white negative film rated at ISO 320, developed in Black-and-white. Below: specs, an exposure guide and similar stocks.

ISO 320Black-and-whiteIn production135
ISO 320
Box speed
Black-and-white negative
Type
Black-and-white
Process
In production
Status
2019-
Years made

Film specifications#

Manufacturer
CatLABS
Film
X FILM 320
Speed
320
Process
B&W
Formats
135
Base
Triacetate
Made in
USA
Status
In production

Character & history#

Medium-speed film, with distinct grain quality, contrast and tonal range, wider exposure latitude up to EI of 1600. Hand rolled onto reloadable cassettes, film edge markings state '5222' indicating this to be Kodak Double-X film stock.

Description adapted from Wikipedia’s “List of photographic films” (CC BY-SA 4.0).

Exposure guide at ISO 320#

Sunny 16 for this film: f/16 at 1/320 s in bright sun. Negative film tolerates 2–3 stops of overexposure; slide film needs accuracy within about ⅓–½ stop.

Lightf/2f/4f/8f/16
EV 16 · Snow / beach, bright sun——1/3200 s1/800 s
EV 15 · Bright sun——1/1600 s1/400 s
EV 14 · Hazy sun—1/3200 s1/800 s1/200 s
EV 13 · Cloudy-bright—1/1600 s1/400 s1/100 s
EV 12 · Overcast / open shade1/3200 s1/800 s1/200 s1/50 s
EV 10 · Sunset1/800 s1/200 s1/50 s1/13 s
EV 8 · Bright interior1/200 s1/50 s1/13 s0.3 s
EV 5 · Home interior at night1/25 s1/6 s0.6 s2.5 s
EV 3 · City street at night1/6 s0.6 s2.5 s10 s

Push & pull options#

Tell your lab how many stops you pushed or pulled so development is adjusted for the whole roll.

AdjustmentRate the film atEffect
Pull 1 stopEI 160Lower contrast, finer grain
Push 1 stopEI 640More contrast and grain
Push 2 stopsEI 1,280Strong contrast, coarse grain, blocked shadows
Push 3 stopsEI 2,560Strong contrast, coarse grain, blocked shadows
Developing Black-and-white: Traditional black-and-white development (e.g. D-76/ID-11, HC-110, Rodinal, XTOL) — easy to do at home.

Long exposures#

Most films suffer reciprocity failure beyond about 1 second: they need more exposure than the meter says. As a rule of thumb add ⅓–1 stop for 1–10 s and 1–2 stops beyond 10 s for older emulsions; modern T-grain films (and Fuji Acros) need much less. Check the manufacturer's datasheet.

More CatLABS films#

Frequently asked questions#

What ISO is CatLABS X FILM 320?

320 — set your meter to ISO 320 for box speed.

Is CatLABS X FILM 320 still made?

Yes, it is currently in production (2019-).

How do I develop CatLABS X FILM 320?

B&W process. Traditional black-and-white development (e.g. D-76/ID-11, HC-110, Rodinal, XTOL) — easy to do at home.

Is CatLABS X FILM 320 available in 35mm?

Yes — formats: 135.

Sources & licences#

Last updated October 03, 2026 · How we calculate · Sources