This would help me a lot

surv0101

As I was working with Daz the other day and using depth of field a lot, I realized that with camera shots that were at angles to the subject, I was "eyeballing" the exact location of the focal distance. I have increased the size of the crosshairs but I thought what would be even better is a plane that you could adjust the opacity of. Then, if you want to put the focal distance right on top of an eyeball, for instance, it would be no problem knowing exactly where it is, and if you could adjust the opacity of the plane to barely visible, it wouldn't hinder your vision getting the shot right. Maybe this is already possible...if it is, I would love to know how to do it.  

CES3D

Here's a tool that's useful when working with DOF:
https://www.daz3d.com/camera-dof

If you choose not to use this tool, you can achieve your idea as follows:

1. Create a new camera by selecting Create > New Camera.
2. Reset the camera's transforms to zero. An easy way to do this is by using Edit > Object > Zero > Zero Selected Item(s) Pose.
3. Create a new Plane Primitive by selecting Create > New Primitive. Set the Primary Axis to Z Positive or Z Negative. The size can be adjusted as needed, and setting Divisions to 1 is sufficient.
4. Make the Plane Primitive a child node of the camera.
5. In the Surfaces Pane, lower the Cutout Opacity of the Plane Primitive to make it semi-transparent.
6. Move the camera to your desired position.
7. Adjust the Z Translate and Scale of the Plane Primitive to position it at the focal point you want for the DOF.
8. Set the camera's Focal Distance to the negative value of the Plane Primitive's Z Translate.
9. During rendering, either hide the Plane Primitive or set its Visible in Render property to Off.

Richard Haseltine

Why not use the built-in guides, looking at the camera from Perspective View (or another camera) to see where they are?

crosswind

Using built-in guides in a Camera will do as Richard said, change value in Sight Line Opacity, FOV Opacity and DOF Plane Color etc. to make them much emphasized.

For repetitive use, you can save a Properties Preset of a Camera with these tweaked properties. Each time you add a Camera with DOF, apply the preset to it.

Or, directly create a Camera Preset with all these emphasized properties ~~ 

Then tweak the camera with Perspective Wiew or Top View

surv0101

CES3D said:

Here's a tool that's useful when working with DOF:
https://www.daz3d.com/camera-dof

If you choose not to use this tool, you can achieve your idea as follows:

1. Create a new camera by selecting Create > New Camera.
2. Reset the camera's transforms to zero. An easy way to do this is by using Edit > Object > Zero > Zero Selected Item(s) Pose.
3. Create a new Plane Primitive by selecting Create > New Primitive. Set the Primary Axis to Z Positive or Z Negative. The size can be adjusted as needed, and setting Divisions to 1 is sufficient.
4. Make the Plane Primitive a child node of the camera.
5. In the Surfaces Pane, lower the Cutout Opacity of the Plane Primitive to make it semi-transparent.
6. Move the camera to your desired position.
7. Adjust the Z Translate and Scale of the Plane Primitive to position it at the focal point you want for the DOF.
8. Set the camera's Focal Distance to the negative value of the Plane Primitive's Z Translate.
9. During rendering, either hide the Plane Primitive or set its Visible in Render property to Off.

I am definitely going to give this a try. But I also love everything Riversoft does, but this might help me understand more things that Daz is capable of...thank you!