Who knows shutter speeds??

I shot some water sports (tubing) for the first time yesterday and the results were 'hit n miss'. Using a 40D + 70-200 2.8L, many of my panning shots were soft. I am guessing the tube was coming by at 15-20mph. Shutter speed was 1/1600. I never really understood why anyone would ever need a shutter speed of 2000 or 4000/sec. Is this a fine example of that need? Seems that shots where the tube was coming right at me or maybe not as fast gave sharper results. Please confirm. Thank you.
SAMPLES HERE:
http://photocamel.com …oads/9784/14935​01_001.jpg
http://photocamel.com …oads/9784/14935​01_002.jpg
http://photocamel.com …oads/9784/14935​01_021.jpg
http://photocamel.com …oads/9784/14935​01_041.jpg

Pictures?

But it sounds reasonable.

you simply need more practise in panning

I would hazard a guess that it's not the shutter speed that's the issue here, it's the focus point and depth of field.

A high shutter speed would imply a wide aperture, and that gives you a relatively narrow depth of field.

Is there any chance you can post some images to confirm?

Need more practice? The shots are perfectly centered as I followed the tube "dead on". Aperture was F4 -F6.3 at 200mm from about 40 feet away. Photo links have been added to original post above. Any help is appreciated.

Well at 200mm with f/4 at 40 feet your DOF is only about 1.8 feet, and a f/6.3 only gets you up to 2.9 feet. If the subject was moving and your AF was not set to servo, or to auto track the movement and update the focus you easily could have been off enough to make it soft.

I you are trying to pan you need a much slower shutter speed. I shoot at a max of 1/250 for a race truck moving at over 100 mph, and get as low as 1/40 or 1/60 sec for effective panning. 1/1600 sec will freeze everything especially at only 20 mph.

And shooting at iso 100, Tv mode, in sunlight, you will end up with an aperture value around f/10-f/14 or so. This will help with your depth of focus.

Also panning that slow is difficult even for someone who pans a lot and is good at it.
Example: Tv mode, iso 100, 1/100sec, f/11. 40D, 70-200mm f/2.8, shot at 125mm.

Ryan, that picture is awesome!

Ryan, nice picture..how did you get that picture..did you move the camera to the left while taking that picture?

Yes I followed the truck through a 180 degree turn with a slow shutter. I picked a spot on the truck and kept my center focus point on that spot.

I only increase my shutter speed when the trucks are coming at me, to 1/500 sec, to keep a little blur in the back ground, but mostly to keep the tires blurry to show speed.

example:

snyper77 wrote in post #5730481
Need more practice? The shots are perfectly centered as I followed the tube "dead on". Aperture was F4 -F6.3 at 200mm from about 40 feet away. Photo links have been added to original post above. Any help is appreciated.

I didn't see it mentioned so I'll ask, Which AF focus mode were you using? If you're using One Shot AF then by the time you take the picture your subject maybe be out of focus, which wouldn't take too long at 20 mp/h!

Yes defiantly AI servo.

Dermit wrote in post #5730517
Well at 200mm with f/4 at 40 feet your DOF is only about 1.8 feet, and a f/6.3 only gets you up to 2.9 feet. If the subject was moving and your AF was not set to servo, or to auto track the movement and update the focus you easily could have been off enough to make it soft.

That looks like the problem to me, too.

On most of the shots you linked the lettering on the edge of the tube seems pretty sharp and, as that is in the middle of the image, I presume that is what you focused on. With the wide aperture you were using the DOF just isn't enough to keep the rider sharp as well, so they become soft and (as they are the main subject) the whole image gives an impression of softness.

You need to either focus on the rider's face, or slow your shutter speed down and close down the aperture to increase DOF (preferably still focusing on the rider of course). A slower shutter speed will also give a better impression of movement and excitement. At 1/1600 they just seem to be floating there, rather than doing 20mph.

Terbo wrote in post #5733458
I didn't see it mentioned so I'll ask, Which AF focus mode were you using? If you're using One Shot AF then by the time you take the picture your subject maybe be out of focus, which wouldn't take too long at 20 mp/h!

I am sorry for leaving that info out. I was in fact using ONE SHOT focusing. Is this my problem?

snyper77 wrote in post #5734249
I am sorry for leaving that info out. I was in fact using ONE SHOT focusing. Is this my problem?

Along with your depth of focus and shutter speed yes.