BEYOND 720nm

diving deeper down into the waves

720 nanometers (millionth of a millimeter) is commonly held as the boundary beyond which visible light shifts into infrared, and becomes no more visible to our eyes.

In this session, I will get deeper into technical details about my experience with Infrared photography.

I would like to give a sense of what IR photography is about, beyond shiny trees and lollypop landscapes; if you are a bnw enthusiast like me, IR will give you the opportunity to experiment with a totally different rendition of luminosity, depending on how anything around absorbs or reflects infrared radiation.

Each camera sensor responds in a slightly different way and even the best lenses - that are optimized for visible light - may sometimes show issues that make their use impractical.

All this is part of the equation, and you don't really know the outcome until you go out, shoot and postproduce.

Postproduction is a fundamental part of the process: no way you can get anything good straight out of the camera;

it might look good for the first few times, but you'll get soon bored of IR if you only stick to that.

If you keep on reading, you will learn more about IR photography and you will have the opportunity to go deep into technical details with some cool graphs.

Should you at any time feel uncomfortable with all the tech-talk, just hit the HOME button and go back to look at some good relaxing pictures.

I hope you'll enjoy.

my IR photography equipment

How it's done

the basics of IR photography

Infrared Photography has nothing to do with night vision:

in fact, it has to be shot in full daylight, the Sun being the major source of Infrared radiation.

What we normally refer to as “light” is a band of electro-magnetic waves, ranging approximately from 400 to 700 nanometers (millionth of a millimeter) in wavelength.

Shorter wavelengths (400nm) are perceived as blue light and longer ones (700nm) as red; all the colors and shades that our eyes can see fit in between these boundaries.

Our receptors are not sensitive to wavelengths that fall out of this narrow band.

Digital sensors, on the contrary, are very sensitive to longer wavelengths up to 1.200nm, far beyond our biological capability and for this reason, digital cameras out of the factory are equipped with a filter that blocks out almost anything from 700nm up.

I modify my cameras by removing the hotmirror (the
IR-block filter mounted in front of the sensor) and then cover the lens with a filter that completely blocks out visible light and lets only waves longer than 720nm

reach the sensor: i.e. infrared light.

What I show in my pictures is technically invisible

to the naked eye.

Postproduction

showing the invisible

There are two basic postproduction techniques when shooting infrared: False Color and BnW.

Filter choice on the shoot makes the difference between what you can and cannot do in postproduction: as you cut deeper into the NIR spectrum, you gradually lose the ability to use color information from the sensor and push your image more and more towards a harsh contrast bnw.

The most characteristic trait of IR photography is how it renders bright foliage opposed to dark skies.

As a personal choice, I generally go for bnw, but I have been experimenting with false color on some occasions and came up with some interesting results.

false color IR 720 nm

RAW and JPG files will give far different results out of the camera; I generally shoot both for this very reason and postproduce JPG files for false color or RAW for bnw.

There is a way in between the two, which is kind of resembled by the JPG straight out of the camera; the final result is a monochrome picture with an altered color sky.