Silverstone GP

[andrewcliffe]

for trackside work I use a Sigma 100-300 f/4 EX lens. 100-300 is about right for most circuit motorsport, although Silverstone is the worst circuit on the calender due to the F1 levels of run-off area!

Spectators require a bit more, or crop more on the computer as they are that bit further away.

[samier]

Good setup, the Canon 7D is new isnt it? How are you finding it? Is that a good replacement for the 5D? Im looking to upgrade my Canon 450 for something new. Just looking at my options.

BTW, theres a couple of pictures here.. looks a bit photoshopped to me...

http://www.karlbowdrey.co.uk/

[andrewcliffe]

The Canon 7D is just over a year old now and they gave it a single number designation, as per all their top bodies. The autofocus in particular is a step up from that used on the xxxD range and the xxD range and is an ideal body for those looking for sports or wildlife photography.

The 5D and 5D Mark II are full frame cameras, whereas the 7D is a crop camera, so they compliment each other rather than replace each other. Full frame cameras are better for people shots and landscape shots and low light level shots. You'll get the same image on a 5D that you would on a traditional 35mm film camera, but on a x1.6 crop camera you get the central 60% of the image, the rest of the image is not recorded. Your 450D has the same crop factor, so the view through the viewfinder between this and a 7D will be the much the same and the lenses will behave in a similar way.

The new 550D and recently announced 60D have the same amount of megapixels, but the autofocus system is not as advanced or quick to react.

[samier]

I do find that on my camera the auto focus is slow to react, just pot luck sometimes if it gets a good focus lock.

Any reason why they have this X1.6 factor, cost?? Surely what you see from the view finder is what you want to have recorded as an image.

[andrewcliffe]

The crop sensor is really down to cost as most people won't either a) care or b) notice, as they will choose lenses to suit their needs.

Focus speed is partly down to the body and partly down to the lens. A 450D with a fast foccusing lens will track things well, a faster camera but with a slow moving lens will produce lots of missed shots. For motorsport you need to use AI-SERVO focussing mode and to half press the shutter button early, track the car and then fully press the button when you're happy.

If you go into a camera shop and handle a full frame camera next to a crop frame camera you'll notice the viewfinder much bigger. The downside is that the frame rate is generally slower.