Rollei Ortho 25 Plus ~ 35mm 36 Exposures

Rollei Ortho 25 Plus is One of the finer grained and more interesting low speed films out there….lovely tones, it’s a technical, orthochromatic black and white photographic film with a nominal sensitivity of ISO 25/15

This lovely film is characterised by a high sensitivity reserve of up to two f-stops, depending upon development.

The results are reminiscent of properties and qualities obtained by a Technical Pan film.

Features: 
• low-speed orthochromatic black and white film
• spectral sensitivity 380 to 610 nm ~ Extremely high resolving power, 330 line pairs/mm, depending on the developer
• special coating to improve the transport properties of the film in the camera
• suitable for use in daylight and artificial light, without any restrictions
• polyester base with high tear resistance, suitable for archiving LE 500.
• very fine grain and high sharpness as a base for excellent-quality negatives
• ideal for scanning and digital processing

Nice eh…but many people are left wondering with exactly is Orthochromatic film?

Well, put simply it’s a bit like this, similar to old fashioned early 20th century emulsions it’s a type of photographic film that is sensitive to blue and green light but not red light.

It has the advantage in that it allows for handling under red safelight and creates a unique visual effect with reds appearing dark, it can offer more contrast than the panchromatic films we’re so used to.  So there!