Thanks for the critics, and so true about the backgrounds :) I was experimenting in PS, made a copy of the image, blurred it fairly strong, made a hide-all mask and then brushed in the background.
It seems that the big decision to make is aperture vs. shutter speed. (isnt it always) getting some blur of spokes, etc., or blurrier backgrounds. Also have been thinking about the best distance and lens zoom, to lower the depth of field. The MX pics were ISO 100, and the light was strong enough to make the settings selection a compromise.... or so I think!
What do you think, arperture first, even if the shutter is oh, 1/1000th ?
Practice and experience ! just like riding
:ride:
for those interested, I use a D200. the MX pics I used a Sigma 50-150 f2.8, which seems to do well. The Flattrack pic I used a Nikkor 28-105.