The problem of depth of field is that it is not a direct physical optics quantity, that is, it is not defined completely by the characteristics of the lens but also involves the film grain size or the resolution and size of the sensor. And there is a lot of subjectivity in evaluating a given printed (or otherwise displayed) photograph and how much of its depth is in focus.

So, for me, I can live with me learning to know my lenses and cameras and light conditions (leading to a choice of film speed, f-stop, and shutter speed). Experience seems, to me, to be the key rather than a nebulous calculation. --Richard

P.S. I know that the Edmund Scientific Imaging tutorial series has an article, "Depth of Field and Depth of Focus," appears to have a lot of quantitative data supporting its definitions, but they derive from some subjective definitions and definitions that are not helpful to use in a calculation in the field or studio.

Heh..it costs more because it does more.
You want less...you'll get less.

Prices aren't plucked out of thin air...everyone is in competition to sell their products...competition keeps it all relative.

That info comes from a site for Sony which has tested which lenses work best on Sony cameras.
There were only two clear winners...which I listed.

If you want to shoot manual...buy a cheapie.
Anything else...pony up.

Unless you are going to keep your Canon lenses...you might want to do that math of selling C lenses...not buying adapter...and pick up two good dedicated Sony lenses instead...used if need be.

or not...