Depth of Field

I wonder if DOF would be better with a Canon 50MP Camera or a Nikon D8100, as against say a 7D2? or a 16MP Camera?

That is a very long and involved topic.  There are many articles on it.  Here's a start:
http://www.cambridgeincolour.com/tutori ... r-size.htm

And then this takes it a bit deeper:
https://photographylife.com/sensor-size ... h-of-field

Make sure you read about circle of confusion - it will help answer all your questions. 

Robert,

Given that you shoot with mostly super telephoto lenses wide open or minimally stopped down the difference would not be huge. Bigger concern is with the new 5D bodies is the to lack of weather sealing which in the conditions you like to shoot in I think would be an issue. Not sure about the Nikon body.

Lou

What I meant to covey is is the DOF the same on Two equal sensor sizes with a great disparity in Pixel quantity?
Say a Canon 5D2 with about 22mp, vs. a Canon 5DR with 50+mp?

The links I provided above will answer the question.  It all depends on how you evaluate those pixels.  Since the two sensors are the same size, a print of equal size viewed from the same distance will have similar DOF but the 50mp one might be able to resolve more detail, not because it has more DOF but because it is sampling the subject at a higher frequency.  But to really understand it, you have to select a circle of confusion appropriate to the size of the pixel and that will be different for those two sensors.  This is covered in the links above.

There is not a simple answer to your question.  

E.J. Peiker wrote:The links I provided above will answer the question.  It all depends on how you evaluate those pixels.  Since the two sensors are the same size, a print of equal size viewed from the same distance will have similar DOF but the 50mp one might be able to resolve more detail, not because it has more DOF but because it is sampling the subject at a higher frequency.  But to really understand it, you have to select a circle of confusion appropriate to the size of the pixel and that will be different for those two sensors.  This is covered in the links above.

There is not a simple answer to your question.  

Actually in my opinion it is a simple answer. 

DOF is defined as a certain acceptable blur on an output medium.  Given two camera bodied with the same lens and the same lens diameter, making the same size output (e.g. print with a bird 6 cm tall), the depth of field will be the same.

In fact change out the lenses but keep the aperture diameters the same and the DOF is still the same.

Only if you want to change the lens aperture diameter, or redefine the size of the circle of confusion, will the DOF change.  For example, in the 50 mpix camera enlarges more or you make the circle of confusion smaller because the print will have more detail, then the DOF changes, but only because you changed the circle of confusion size.

rnclark wrote:

E.J. Peiker wrote:The links I provided above will answer the question.  It all depends on how you evaluate those pixels.  Since the two sensors are the same size, a print of equal size viewed from the same distance will have similar DOF but the 50mp one might be able to resolve more detail, not because it has more DOF but because it is sampling the subject at a higher frequency.  But to really understand it, you have to select a circle of confusion appropriate to the size of the pixel and that will be different for those two sensors.  This is covered in the links above.

There is not a simple answer to your question.  

Actually in my opinion it is a simple answer. 

DOF is defined as a certain acceptable blur on an output medium.  Given two camera bodied with the same lens and the same lens diameter, making the same size output (e.g. print with a bird 6 cm tall), the depth of field will be the same.

In fact change out the lenses but keep the aperture diameters the same and the DOF is still the same.

Only if you want to change the lens aperture diameter, or redefine the size of the circle of confusion, will the DOF change.  For example, in the 50 mpix camera enlarges more or you make the circle of confusion smaller because the print will have more detail, then the DOF changes, but only because you changed the circle of confusion size.

Well that's pretty much what I said but when you enter circle of confusion into the mix, as we both have, for many, well, the subject becomes confusing.  It is simple for you and me but the question alone posted by Robert and our answers proves that it is not so simple