Digital Zone System ~ Validation Testing

I wanted to prove to myself something about a Digital Zone System that I've been working on.  

What I wanted to prove was that once I'd set up an input correction curve for each camera I own that the result would match the output of my other cameras, each with their own unique input correction curve.

The cameras I own span recent digital sensor development and manufacturing.  For this validation I chose two different formats, two different megapixel counts, and three different years sensor implementations.

In each case I spot metered the light area to Zone 7 and let the shadows fall where they will.  I did this because in digital I meter for the highlights and process for the shadows.  Keeping in mind, of course, this is the exact opposite of what we do with film.

Here's what I see ->

 

 

To my eyes this is an excellent match. Each input correction curve accurately matches the 1EV step as described by the original Zone System and adapted here to digital.

So here's a little game.  Want to win a free beer?  Tell me which camera made which image.

For me that's an easy bet for the house.  I seriously doubt anyone will be able to pass this test.  In fact, it's rather irrelevant.  Though it does make the point that if we understand our tools and set up our processing environments correctly, manufacturer to manufacturer variations, sensor to sensor variations, and generation to generation developments can all be "leveled" to the point good image making doesn't depend on tools as much as some would have us believe.