Lens Filter

Spectral Sensitivity of B&W Film – A Deep Dive into Orthochromatic, Panchromatic and All the Rest

Even if you’re new to film photography, you’ve probably heard about the various types of B&W emulsions which are out there: orthochromatic, panchromatic, infrared and so on. If you’re a bit more experienced – or just a nerd – you might even know what these terms mean. They refer to different spectral sensitivities – how sensitive the film is to different wavelengths (colours) of light.

The term spectral sensitivity might sound boring and/or scary – the kind of jargon which photography veterans use to bamboozle and discourage newbies. In this article, I’ll try to demystify the term, and to explain how an understanding of film characteristics can help us get the kind of results we want.

There are so many different types of B&W film out there. Exploring their variety and complexity can expand our creative options. Besides, it’s fun!

Colour Theory for Black and White Photography Part 1: Digital and Analogue Filters – by Sroyon

A black and white photograph “translates” the colours of the original scene into shades of grey. This “translation” or conversion is done by the film (in film photography), or by the sensor and software (in digital).

Some colour-to-B&W conversions seem simple enough. If the original scene has blacks, whites and greys, in a B&W photograph we would expect them to be rendered as blacks, whites and greys respectively. Likewise, we would expect a dark green to be rendered as dark grey, and a light green to be rendered as light grey.

What about a dark green and a dark red? That’s where things get more complicated. In a B&W photograph, we would expect them both to be rendered as shades of grey. But will they be the same shade of grey, or will one be darker than the other? The answer depends not just on the original shades of green and red, but also on the conversion process.

So how does this conversion process work? How can we control it? Why would we even want to? This is the first of two posts in which I try to answer some of these questions.

Pro Mist Filters

Tiffen Black Pro Mist Filter (1/8), on Digital & MF film – by Pierre-Alix Favillier

I always look forward to seeing 35mmc articles popping into my inbox on a daily basis and read most of them avidly. I also listen to podcasts, read about lenses, watch YouTube videos, and love experimenting with photography. Why do I do that? I guess because a little bit like Hamish, I enjoy the process of photography almost as much as I enjoy the results. That way when I get a keeper, it’s an even better feeling, because I’ve also enjoyed sourcing and choosing the camera, a focal length, the emulsion and finally thought about how I would expose my shot before I released that shutter.

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