New Canon 100D not focusing correctly

R2D2 wrote:

Thanks for posting the samples.

The real crux of the problem stems from shooting in Auto mode.

I'd highly recommend shooting in one of the "Creative Modes." This will allow the photographer to select the single center AF point with which to track the vehicle. Use AI Servo AF. I suspect that the busy background threw the (multi) AF off.

Not sure where my reply went. Someone must have gotten upset and complained.

The OP wants to use the camera in the same manner as the old one. It's embarrassing to advise to have to use more complex settings on the new camera to get as good as the results as with his old camera!

The "Creative Modes" will also let you set a higher ISO to combat both camera shake and subject motion blur (both of which are evident in your sample). I highly recommend starting at ISO 400 (which would have increased the shutter speed dramatically). Race cars (planes, helmeted athletes, etc) can withstand copious amounts of both sharpening and noise reduction.

And don't forget that the camera is now producing almost double the megapixels as the old one. Couple this with the 50% increase in focal length with the new lens, and the images viewed at 100% will look significantly different than those from the old setup.

Also, be sure to remove any protective filters from the lenses to improve both autofocus acquisition and IQ.

Good luck!

R2