APS-C vs Full Frame. Examples and Comparisons.

So far, the digital camera I want does not exist. I would like a small lightweight full frame digital camera about the size of the Fuji X100 series cameras, or better yet, smaller and lighter. The interest is there because the best small 35mm film compacts are selling for $200 to over $1000 for a used camera. And it’s more than just the film-only crowd that are paying $1000+ for a used Contax T3. Gorgeous camera by the way.

My favorite walk-around prime lens focal length is 35mm or 40mm on a full frame camera.  When using a camera with an APS-C size sensor the equivalent focal would translate to between 22mm to 24mm to match the full frame's angle of view.

My conundrum is do I really need a small, lightweight full frame digital camera when there are so many APS-C, MFT, and 1.0 inch sensor cameras that are the perfect size and weight for me?

I'm sheltered at home because of the COVID-19 directives, and it's raining outside. What a great time to test and compare APS-C to full frame sensors when used with my favorite semi-wide angle focal length lens.

The equipment that I used...
APS-C sensor: Fuji XT-1 with the Fujinon 23mm f2

Full frame sensor: Nikon D750 with the Nikkor AF-D 35mm F2

The subject is a Heath Ceramics coffee mug. Sorry, my model couldn't make it over here.

I'm testing for the overall "look", out-of-focus appearance, noise, as well as noting highlight and shadow detail. Not a scientific test, but an observational one. The images are unedited RAW files which is why the color and exposure are different from each camera. (There is one image example where I exposure matched the other camera.)

Fuji 23mm @ f2 ISO 800

Nikkor 35mm @f2 ISO 800

Fuji 23mm @ f4 ISO 800

Nikkor 35mm @ f4 ISO 1250

Fuji 23mm @ f8 ISO 3200

Nikkor 35mm @ f8 ISO 3200

Here I edited the Fuji exposure in Lightroom to try to match the Nikon original.

Nikkor 35mm @ f4 ISO 1250

Fuji 23mm @ f4 ISO 800

Predictably, the larger sensor has less noise at ISO 3200, and as far as the "look" is concerned, the full frame image has a "smoother" look, or should I say the smaller sensor has more micro-contrast?

Both of these systems produce wonderful images, and if I had used a Sony, Olympus, Panasonic, Leica, Canon, Sigma, Ricoh, Pentax they would also be as good or better. So, do I still want the small, lightweight full frame digital camera that does not yet exist?

Yep.