Wolfen P400

Wolfen P400 is ORWO's still-photography rebrand of their N74plus surveillance stock, modified by removing the anti-halation backing layer so it behaves in standard B&W chemistry. The film is panchromatic, coated on a polyester base, and made on the same Bitterfeld-Wolfen line that produces the NC400 and NC500 color stocks. ORWO has been running film through this site, in various corporate forms, since 1910.

The character is high contrast with a fairly straight tonal curve and grain that sits closer to Tri-X than to T-Max 400. There is real edge bite in Rodinal 1:50. HC-110 dilution B around eight minutes gives cleaner negatives with less grain texture but loses some of the cinematic feel that drew people to the stock in the first place. D-76 stock works but feels middle-of-the-road. Most reviewers settle on Rodinal or HC-110.

Rated at box speed, P400 behaves like a normal 400 ASA film with a slightly steeper midtone curve than HP5+. Push it to 800 and it holds; push to 1600 in Microphen and you start seeing the surveillance-stock heritage in the way the highlights blow before the shadows recover. The polyester base is thinner and stiffer than acetate, which loads cleanly but can fight scanners that expect a softer base.

Compared with HP5+ the grain is more visible in 35mm but the lower midtones run darker. Against Foma 400, P400 is sharper and less grainy. Against Tri-X it gives up some salt-and-pepper texture for cleaner highlights.

Available in 35mm 36 exposure currently. No 120 or sheet sizes from ORWO yet, which is a limitation if you want this look in medium format.

The reciprocity exponent is 1.31, consistent with traditional silver-grain motion picture stocks. Zone Light Meter applies the correction past one second. A 30-second meter reading lands at about 90 seconds on the negative. At ISO 400 the threshold comes up less than with slower films, but it is real once you stop down past f/8 indoors.