Black and White and Infrared All Over
With paper newspapers in such declined, does that joke even mean anything any more?
It was known as the newspaper riddle:
Q. What’s black and white, and red all over?
A. Newspapers
Red/read being the operative pun (in case I have readers who don’t know what a newspaper is, like the grandkids maybe).
Anyway, in this case, infrared. (Does everyone know what infrared is? It’s like that has a longer wavelength that the color red does, and is thus invisible to the eye.)
Ahem. What a long prelude, and possibly unnecessary, but unless you want to do a zoom with me every day, I guess I’ll have to assume. Which makes me a…donkey (one-joke limit, sorry).
So I had one of my cameras modified, so that is instead of being sensitive to visible light, it is sensitive to infrared light. The cut-off is 720 nanometers, which is at far end of red in the color spectrum. (Some typical wavelengths: 300nm is ultra-violet, which are very short wavelengths and also invisible to the eye; blue can be found in the range of 450-500; green 500-570; yellow 570-590; orange 590-620, and red is 620 to 750nm.
So the 720nm cutoff lets in deep reds, and infrared (figure 750-1200nm for IR). Various sensors respond different to deep infrared, so my idea was to test my camera’s sensor on a sunny day and see just what it records. As you would expect from a 720nm cutoff, there’s still a little bit of color, so I set up my camera to record in black and white. That covers up the red nicely.
The other good news is that the sensor remains nice and sharp; the details are really impressive. The camera is recording reflected infrared, so most plants show up as quite bright (they use light in the range of 400-700nm for their chemistry). The grass and the leaves and needles on the trees show this very clearly.
The blue sky is quite dark compared to the clouds, which means that clouds are reflecting not just the colors we humans can see, but also a lot of IR light as well.
This doesn’t quite look like a normal black and white picture because of the IR light reflecting from plants, but…I rather like the look of it. I think this is going to be a fun and artistic way to do B&W photos.
The sunlight really makes this shot pop; test photos I took under cloudy skies down have quite as much punch. This interior shots shows the value of this setup for B&W indoors:
The details are very sharp in the focused areas, with very nice film-like gray tones in both focused and soft areas. That’s our living room, lit just by daylight, so the camera also remains quite sensitive to infrared light, which is handy for sure.
I’m looking forward to using this setup for my creative B&W work.