Rollei Ortho 25 Plus

Orthochromatic film is blind to red. This single fact shapes everything about Rollei Ortho 25 Plus and why you would or would not choose it. Lips render darker than their surrounding skin. Red objects go dark gray or black. Skin tones lose the warmth that panchromatic film picks up from subcutaneous blood color and render cooler, flatter, and more alabaster. Portrait painters and certain fine-art photographers have wanted exactly that for a century.

The film itself comes from a document copy lineage, which means the original design intent was sharp separation between black text and white paper at high contrast. That high-contrast bias carries over into pictorial use: the curve is steeper than HP5+ or Delta 100, and the highlight-to-shadow separation is more compressed at the extremes. For still life, product, and architecture work this produces clean, graphic negatives. For portraits it creates the waxy, sculpted quality associated with nineteenth-century wet-plate work.

Rating at ISO 25 is accurate under tungsten or daylight. The spectral blind spot means that under heavy red or orange light sources you may need to adjust, but ordinary ambient shooting is straightforward. Develop in Rodinal 1:50 for tight grain and high acutance; try a staining developer like Pyrocat-HD if you want to hold shadow detail with a softer gradation.

It is available in 35mm, 120, and sheet film in 4x5, 5x7, and 8x10. Adox Ortho 25 covers similar territory in 35mm and sheet for shooters who prefer that emulsion.

The reciprocity exponent is 1.31. At ISO 25, one second of metered exposure arrives quickly in indoor or filtered situations. Zone Light Meter starts correcting automatically at that threshold, which matters for close-up still life work where depth of field demands f/16 or smaller.