I am a long time visitor to Silverstone and have heard so many times that it is not a good circuit for photographers. i don't agree with this 100% although to some extent my opinion is influenced by the types of images I try to take and, importantly, what grandstands are open (and if your ticket gives you access to them).
For example, I was at the Williams 40th birthday event last Friday and from the front row of Club grandstand, I was able to take numerous photos with uninterrupted views of the cars (albeit from a slightly "down" angle).
Over the years, I've walked the track so many times (both outside and inside the circuit) and there are probably few areas I haven't tried to take a photo from. Grandstand wise, I've taken photos from virtually every location around the circuit and I have my favourites. For "head on" /freeze action, I prefer Copse and Stowe grandstands. For panning, which I do about 90% of the time, I enjoy Club, Becketts, Village (B?) and, in my opinion, the best location - the F1 paddock grandstand which has been open for the last couple of Silverstone Classics and the 2016 WEC in April. Sadly it wasn't open for the WEC this year.
Please bear in mind though, that I only go into tnose grandstands which are open on days when there is a "roving grandstand" ticket. I haven't gone to the F1 GP for years and have no idea if any of the Friday/Saturday tickets give roving grandstand access. The one grandstand I would love to take photos from would be the BRDC grandtsand at the end of the new pit straight. Absolutley zero chance!
At ground level there are a couple of locations around the circuit where there are narrow "slits" in the fence - the one I have in mind is a few feet wide and only about 9" tall - just enough to poke a zoom lens through. It tends to be very busy, though, and I often have to queue up with 5/6 others. It's all very good natured though as most of the time you are amongst like minded souls!
When all else fails and I have to shoot through the fence, I normally focus manually and use the widest aperture on the lens to give the best chance of making the fence "invisible".
Come to think of it, there are also a few raised areas where you can just about see over the fence but they tend to be busy. Of the ones I have used, there are tiered concrete steps at Luffield but it is a relatively "slow" corner. Also, if you manage to get into the rear of the pits, there is a raised grass bank (opposite Club grandstand). This is on the inside of the circuit and you can "pan" with success provided not too may people are there.
The only other thing to say is if you're shooting from a grandstand then the further back in the grandstand you are, the more chance you have of getting one of the roof pylons in shot if you pan. Obvious I know.
I have only ever taken photos from the designated spectator areas.
I hope the above is some help. I would encourage you to "walk the circuit" next time you go, stopping at as many grandstands which are open as you can. Go and sit down, if only for 5 minutes and see what sort of shots might be possible. SImilar with taking photos through the outer fence. Stop frequently, go manual focus and see what you get.
Hope this helps. I have the time to answer more questions if you have any. I have never posted any of my motor racing photos on -line before, but if it helps, i might be persuaded!!!
I appreciate that there will be far more experienced photographers who have been to Silverstone more times than me and who may have different opinions to mine.
Regards
Ps I also frequently hear/read that 300mm is not long enough for Silverstone. That may be true if you are shooting "head on" from distance, but if panning, then 300mm is more than enough for me (I use a Canon 70-300 L).
PPS just remembered that I've taken some super slow panning shots over the fence (could be armco, not sure) at Brooklands. This was at last year's Classic. Not sure how close you can get at other times. Also, Aintree grandstand (not sure if it's called that) was open for the Classic and I managed to pan at about 1/40 or 50.
