Hi Lewis,
These look ok but it's pretty clear you suffered from the bright sunshine which has softened a few of them up. The ones from Brooklands look to be taken in better conditions (in terms of sun position) which has limited the effect of the fence. I'm not sure if you shot in jpeg or raw, the latter would allow you more scope for corrections. #4 looks like a good shot to me, but your sharpening is way OTT. #1 is a classic angle but just hasn't achieved critical sharpness (same with #3 but down to shutter speed), this is probably down to a combination of glare and the use of a TC which has hindered your AF accuracy - this happens (a lot) and, at least for me, means taking a lot of shots and hoping that a few come out properly. #2 & #5 look like the highlights and shadows are all over the place (i'm guessing this is a result of post process in an attempt to compensate for crazy contrasty light), they look borderline faux HDR so could be improved in that respect. #6 is technically perfect (in terms of camera capture) ... I'd be tempted to tweak the highlights, shadows, white and black points just to make it as good as it can be, artistically though the angle isn't quite as interesting and he isn't pushing on this lap.
A CPL can provide a greater margin to work with when shooting through the fence but you often lose 2 stops of light, this can hurt AF performance significantly when using a TC on f5.6 lens.
All this said, it depends what your objective is... for me the majority are not sharp enough where they need to be or do not have enough blurred motion to be considered intentional (this is a fine balancing act in my experience), at web sizes that probably doesn't matter but a print will draw attention to any shortcomings in the image. #1 is the best for visual impact - but needs to be sharp, #4 has great colour and is well captured, just needs some tweaks to processing and I think it could be a great shot, #6 technically spot on but artistically questionable
Personally I would have ditched the TC for Brooklands to give myself the best chance at accurate focus - the same goes for Copse (at least as an experiment for a few shots) and crop (limited size images as a result), using your lens at f5.6 would give you a better chance at avoiding the fence but the trade off is obviously reach.
Similar conditions to what you faced at copse... with bare 400 f5.6 - fullsize it pushed 3500px wide
On the Limit by
Jonny Henchman, on Flickr
An example of the processing required to get there, you can see similar contrast issues and the familiar hint of grey in the original (different light conditions though)
Compare by
Jonny Henchman, on Flickr
The key when working with FF and under reach limitations through the fence, is to accept that you'll have to do some form of processing to get the most out of your images - so the main concern is to get the best raw materials to start with.
Sorry to go on so, hopefully that's helpful
rubbish by lewis wilson, on Flickr
Josh Brookes by lewis wilson, on Flickr
Jakub Smrz by lewis wilson, on Flickr
James Ellison by lewis wilson, on Flickr
Josh Brookes by lewis wilson, on Flickr
Shane "Shakey" Byrne by lewis wilson, on Flickr
James Rispoli by lewis wilson, on Flickr
