Lense focus

[goatydude]

Hi, how do I tell if my lense is focusing properly is there any sort of test.

I find when shooting motorsport even with small apertures I seem to struggle to get the whole car in focus from front to back, usually the back is slightly out of focus when focusing on the front of the car when the car is coming towards me.

Was using apertures of up to f18 on the weekend and found I had this problem in say 70% of shots where the car is coming towards me.

Have tried a different camera body and had the same problem, trying to work out if it is my technique or equipment issue.

example taken at f10 1/250 iso100, with 30D 70-200 2.8L


http://i268.photobucket.com/albums/jj38/canno1_2008/31mayhillclimb1150.jpg


Thanks
Daniel

[ryant35]

With the slow shutter you need the car to be moving perpendicular to you to get the entire car in focus. This isn't based on depth of focus, but the movement of the car. This is a tough angle to pan correctly.

[Bicknell55]

Take the same shot at 1/800 or faster, that should answer your question.

[k_wakasugi]

Yup yup, 1/250th is too slow to capture moving that fast.

[Cadwell]

Yup yup, 1/250th is too slow to capture moving that fast.

Oh... right.

http://www.racepicsuk.com/

52,000 plus motorsport images none taken at faster than 1/320th and most at 1/250th or slower.

[ryant35]

Yup yup, 1/250th is too slow to capture moving that fast.

Not if you do it right.

[k_wakasugi]

Sorry, my fault! Definitely wasn't specific enough. Obviously it would depend on the direction it was heading, the distance from the camera, panning technique, ...on second thought, I don't know what I was thinking when I posted that. I guess I meant to say in that particular instance.

[goatydude]

Thanks guys,

So its more to do with the way the car is travelling across the frame in this particular shot.

How should I tackle the the situation next time??? The car Had just come through a reasonably tight left and was into a sweeping right, this shot was taken in the middle of the transition from left to right.

Obviously I could pan as the car comes past or pick a different angle that would have the car coming more towards me.

Would a faster shutter speed work while keeping the wheels blurry??

Cadwell you have a lot of shots taken from a similar angle. What do you do????

Thanks
Daniel