Zooming with the magnifier isn't going to change how many pixels are used to draw a grid cell. If you make the window small enough you will see the entire grid disappear because the calculated cell width will fall below zero. If you drag the window handles large enough you will see the handles. I think my explanation should be very intuitive.
Gil, I was using magnifier to magnify the view, I didn't expect anything more out of it. I understand the grid will not appear until the window is a specific size.
I did some more testing. I made two small 2x2 pixels matrix. I then created a group for these two matrix. I kept the default minimal grid. When I opened effect assist I saw a huge grid. I then went back to the group and changed from 400 to 10. I then saw the circles.
So this poses another question, if minimal grid is selected then why is the effect assist showing what's in the grid size, shouldn't it use the minimal size necessary?
Gil, your explanations are always very intuitive.
James