Hi Craig,
The set up that you have is pretty large. The spray-cans are larger than an average human is. The settings are for a wide angle lens. I can see you like to counteract both [?} with a F/0.1.
If the results works—the numbers are of minor priority ;o)
Depth Pass. This is an information channel. Not an image channel. Each pixel, if the camera is set up, represents one single measurement in space. Hence why it never should be Anti-Aliased for example. It is since the late ‘90s a discussion that comes up from time to time, but oversampling is the only answer here. I mentioned it, as the HD settings is given in both, your Product as well as in the export (Ausgabe). For any use this channel needs to be at least in UHD or better the 8K version of it. Yes, there is a lot of nonsense on the web about this. Please ignore it. Information passes loses their usefulness if calculated with AA. The quality would be weak, to say the least.
The reason why it has no “eye” symbol is given in the fact that it is an information channel, like a normal pass or a position-pass. It is, again, not an image pass, so it doesn’t calculate inside of the Multi-Pass representation.
The Depth path is based on settings of the camera {detail] and optional based on Render-Settings. It has NOTHING to do with the physical camera nor is in sync with any of its setting regarding DOF.
Real DOF goes though glass, smoke, mirrors, etc. in other words, sometimes it contains several layers of depth per pixels, which is not possible with the “depth pass”. To AntiAlias these several values is not possible. Hence why “Deep Compositing” was invented a while ago, but not available so far here.
One of the main problems with 2D is based on the fact that with a sensor size we leave the idea of an one ray per pixel only. Which is more complex. Hidden objects can become visible again…etc. However, the main problem is DOF and motion blur, which is not solved in compositing with 2D representations. It never will.
DOF is certainly anchored in photography/cinematography and not originally in 3D. The understanding and its implementation of it is retrieved from practical measurements and examples taken with typical lenses. Since Cinema 4D has changed the idea of Units to real world measurements based on many needs, e.g., dynamics, the DOF settings follow real world measurements. To set up things ten times larger makes everything a little bit more complex, but yes sometimes it makes more sense. I’m not certain if a spray can in, e.g., “20+ cm” would be more complicated ;o)
The differences between a 3D based DOF (shallow/bokeh) and a 2D based (post and plug ins) might not be visible always, but most of the time an educated eye can spot it a mile away ;o)
Since million of peoples are now into professional photography, this educated eye will be more and more standard, to say the least.
I hope I could clear your question and as you requested, “explained” it. Let me know if you have any questions. I do photography with SLR since the late ‘70s, and have recently published nearly 200 tutorials about—for 3D artists, see below. All well researched and based on long time practice. (... and I avoid the typical trap to extrapolate knowledge from analog photography, which is a different beast all by itself)
All the best
Images, this is the MP, and it looks OK. You can also see that the Depth pass is black, which is explained in the image on the right, this information pass is not set up, [not adjusted later in the render setting options]. The second camera has a set up for it, I saw that! :o)