@M3RCHLZ4 Nikon D90 and if I remember correctly these were taken with a Sigma 10-20mm, except for 2 which I think is my Tamron 17-50 f2.8
Thanks for the reply....how do you find the sigma 10-20? i'm looking of buying similar lens but am not sure what to get....
I would do some quick guessimates in my head - for example lets say the cars my photo were travelling at 60km's per hour (roughly 40mph), thats 1000 metres per minute, or roughly 16 metres in a second or 1 metre in 1/16 of a second. Closest shutter speed I have is 1/15. Thats probably a reasonable starting point, may need to tweak it depending on how much blur you need and obviously it depends on how fast the cars are moving
Its one of my favourite lens, I look the look from ultra wide angle lens - check out my flickr stream for loads more examples.
(Ok yes I guess if you start peeking at individual pixels you might see some flaws, but don't let that worry you)