I set the crosshair length to 500 pixels but I think in a perspective view this looks wrong.
The screenshot is a screenshot of a screenshot so I was able to draw the second circle around the first center snap. The black curve is a circle too and the white crosshair would need to be scaled in the cplane otherwise this hurts my eyes 
@mary My preference is the crosshairs are always vertical and horizontal on the screen, not parallel to the Cplane u and v axes. The current small cross with a hole icon works this way.
Sometimes I’m working in Perspective view and need to select a location on a photo-textured surface. I need the crosshairs to remain vertical and horizontal as I rotate the view.
a little or adjustable dot would be my preferred crosshair. if we could even make our own?
@mary I using using cursor crosshairs today, working with photo textured meshes placing points and making measurements. Several times while in the perspective viewport it would have been very helpful for the crosshairs to remain horizontal and vertical on the screen, as if fixed to the camera, rather than aligned with the Cplane.
