Car shots - drifting blurry front or back

[Yella Fella]

Guys,

I'm having some issues (I've noticed as of late) when capturing car stuff, I have a lot to learn with panning etc, but I've noticed when capturing cars facing around 30/45 degrees to me i.e. drifting sessions. Shooting using Tv mode at 1/125 speeds, so apertures are usually around f11 onwards on a bright noon day.

It seems that my camera only captures around 2/3 in focus, its either the front part that's in focus, or the rear part that's in focus; bringing the other end out of focus/blurred.

Have I got my settings wrong as such? Or just not shooting correctly?

[sandpiper]

Could be you are using too wide an aperture to get sufficient DoF to get the whole car in focus.

More likely though, the car is sharp at the point you are panning with and the other end is moving at a different speed (relative to your position), due to the drift, so you are seeing some motion blur.

Kinda hard to say for sure, unless you post a pic for us to look at we are just guessing.

[EDIT] Just read your post again and at f/11 the former seems even less likely to be the problem, depends on your focal length and distance though, but it is probably motion blur.

[DC Fan]

It seems that my camera only captures around 2/3 in focus, its either the front part that's in focus, or the rear part that's in focus; bringing the other end out of focus/blurred. Have I got my settings wrong as such? Or just not shooting correctly?

Nothing's wrong. That's what happens sometimes when you use a slow shutter speed to capture a rapidly moving object.

http://www.kevinlillard.com/racing/20100703a0829.jpg

Focal Length: 115.0mm
Aperture: f/16.0
Exposure Time: 0.020 s (1/50)
ISO equiv: 100
Exposure Bias: none
Metering Mode: Matrix
Exposure: shutter priority (semi-auto)
White Balance: Auto
Flash Fired: No
Color Space: sRGB


http://www.kevinlillard.com/racing/200907250228a.jpg


Focal Length: 220.0mm
Aperture: f/10.0
Exposure Time: 0.017 s (1/60)
ISO equiv: 100
Exposure Bias: none
Metering Mode: Matrix
Exposure: shutter priority (semi-auto)
White Balance: Auto
Flash Fired: No
Color Space: sRGB


The short explanation: the different sections of a moving car are moving at different speeds in relation to a camera's position during a panning shot. The use of slow shutter speeds exaggerates that difference and can make different parts of a car appear to be out of focus. The only solutions are to use a much higher shutter speed - which defeats the purpose of the panning shot - or to take lots of pictures and hope one or two are perfect.

[Heavy D]

There is a post somewhere that explains all this. From the focal plane of your lens different parts of the car are going at different speeds ie. front to back. So effectively the only way to get the whole car in focus is to have the car in perfect parallel with the focal plane of your lens. I'll search for the thread and see if I can find it, but be assured your doing nothing wrong.

[Heavy D]

http://photography-on-the.net/forum/showthread.php?t=487139

This is not the post I had in mind but it works....pretty darn good explanation with drawings..plus a GREAT shot to view.
Hope that helps.
Heavy D

[afviper]

I have the same problem with most of the panning shots I take, although a few do come out perfect. The way I understand the problem is that the angle of the front of the car in relation to you is changing at a certain rate for the duration of the exposure. If you pan at that rate the front of the car will be in focus. The angle of the rear of the car in relation to you is changing at a slightly different rate and the rear of the car will be a bit blurry. The link above explains it all clearly.

[PhotosGuy]

Nothing's wrong. That's what happens sometimes when you use a slow shutter speed to capture a rapidly moving object. I agree. You can up your shutter speed, or lower it some more & shoot for the effect:
Dream Cruise 2010 - Sitting on the curb... (http://photography-on-the.net/forum/showthread.php?t=920630)