Who Cropped My Sensor?

by | Dec 23, 2019

Today’s Rant from Joe Farace

For reasons that I don’t fully understand, the term “crop sensor” gets tossed around on Internet forums when people refer to digital cameras with sensor sizes that are smaller than the 24x36mm full frame 35mm film standard. But is it really a standard? Unlike Who Shot Roger Rabbit?, it’s why somebody cropped my sensor.

in 1925, when Oscar Barnack  developed the camera that came to be known as Leica he wanted to use movie film sideways doubling it’s 18x24mm format to 24x36mm. One story about the 35mm motion picture film format, perhaps apocryphal, was that when Thomas Edison was asked by his workers how wide to cut the film, he held up his thumb and forefinger and said, “about this wide.”

Lately, with new full frame mirrorless cameras popping up all over the place, 24x36mm is being treated like the Holy Grail of imaging. It’s not. That first Leica may have used 24×36 but other early 35mm cameras, including the original Olympus Pen, used 18x24mm and early Nikon, Minolta and other Japanese rangefinders initially adopted 24x32mm before standardizing om 24x36mm.

How I made this shot: I photographed Stevie with a APS-C format Canon EOS 60D with its 22.3 x 14.9mm sensor. Lens was an EF2 8-135mm f/3.5-5.6 IS USM (at 65mm) with an exposure of 1/125 sec at f/11 and ISO 100. Lighting was provided by two Multiblitz monolights: The main light with an umbrella mounted is at camera right, the second with standard reflector attached is at camera left and aimed at Stevie’s back. Backdrop was a large, inexpensive muslin that was later destroyed in the flood that damaged my basement, including my home studio.

What’s talking about film cameras have to do with sensor size? Nikon’s D1 was introduced in 1999 with a 23.7×15.6mm sensor. When Canon introduced the D30 in 2000, the camera’s sensor size was 22.7×15.1mm. Even after Canon introduced the full frame EOS-1D in 2001, Nikon insisted their 23.7×15.6mm was more than adequate and didn’t join the full-frame parade until 2007’s launch of the D3.

Olympus, much like Sony, was always willing to go their own way and introduced their Four-Thirds system at photokina in 2012 and I was there at the launch looking at a wooden prototype while listening to a German professor explaining why 18×13.5mm was the “perfect sensor size” for digital imaging. The Four-Thirds system is now long dead but the format lives on in sensors used by Micro Four-thirds mirrorless cameras from Olympus and Panasonic.

Some people, like my friend Jack, thinks the term “mirrorless camera” is synonymous with Micro Four-thirds but it’s not. Some mirrorless cameras use full-frame sensors, others use APS-C or 23.5x 5.6mm formats. For younger reader APS refers to the Advanced Photo System that Kodak launched in 1996. It was an experiment in film formats but before it could catch on was overtaken by digital capture and quickly became obsolete. The APS system used multi-format capture, including APS-C or 25.1×16.7 mm, which as you can see is not quite the same as what digital camera makers call this same format.

And so, dear readers what does “crop sensor” mean? If film shooters refer to roll film as 6×6, 6×7, and 6×9 and sheet film as 4×5, 5×7, and 8×10, why can’t we refer to the sensor size by its actual measurements because as you can see, their ain’t nothing standard about ”crop.”

If you enjoyed today’s blog post and would like to buy Joe a cup of Earl Grey tea or maybe a cup of hot chocolate ($2.50), click here. And if you do, thanks so much.