Read up on a technique called "panning"..

Consider prefocussing. Manual focus on an object you know the drivers will pass closely. Then leave your focus there and just press the button when they pass. Works better at high shutter speeds.Don't wait for the Nikon D-whatever, have fun now!http://www.flickr.com/photos/j_wijnands/..

If your DSLR is a Canon, you probably have a "custom function" you can set which will separate the locks-exposure and locks-focus features. I have set autofocus to the * button, so I focus only when I want to focus, and that's completely separate from when I want to shoot..

[ e d @ h a l l e yc c ] http://www.halley.cc/pix/..

And if you don't have a feature like that just focus and flip to mf.Don't wait for the Nikon D-whatever, have fun now!http://www.flickr.com/photos/j_wijnands/..

Thanks for the replies guys..

Panning. If I auto focus on the object as it is approaching (holding the trigger half way) and follow the object, will the camera continue to adjust focus as the object gets closer?.

As far as the exposure/focus lock goes, I've been doing some reading on it but I can't seem to wrap my head around it. My thought is if I focus on the object early then use the focus lock feature, will that prevent the camera from re-adjusting focus as the object gets closer or will it keep the object that you have locked in focus by re-adjusting as it approaches?.

Boy, I hope that makes sense...

Gouie wrote:.

Thanks for the replies guys..

Panning. If I auto focus on the object as it is approaching (holdingthe trigger half way) and follow the object, will the camera continueto adjust focus as the object gets closer?.

If you have an AF-C mode then yes..

As far as the exposure/focus lock goes, I've been doing some readingon it but I can't seem to wrap my head around it. My thought is if Ifocus on the object early then use the focus lock feature, will thatprevent the camera from re-adjusting focus as the object gets closeror will it keep the object that you have locked in focus byre-adjusting as it approaches?.

The former but check your manual..

You're missing pre-focus though. The whole idea of that is that you focus where your subject will be and just pay attention to shooting at the right time.Don't wait for the Nikon D-whatever, have fun now!http://www.flickr.com/photos/j_wijnands/..

I see. So, lets see if I've grasped this..

If I'm not using AF-C and I pre-focus using the focus lock, the camera will not adjust as I move to find the object. Theory is it will still be in focus based on the area I pre-defined. Track the object and when it enters the pre-focused area things should be in focus..

As far as continuous focus goes, find the object before it enters the target area then press the trigger half way. Continue holding the trigger, following the object. When it gets to where you want it to be, take the picture. The camera will be continually focusing as the camera is moved...

Or you could just use the sport mode which will switch it to AF-C mode. exposure lock on the D40 from what I've found is quite easy. half click, focus, hold the exposure lock button down (near the shutter release button, i'm sure you already know where it is)..

I'm wondering though, if you use exposure lock... you're almost going to have to guarantee that the next bike is going to cross your field of view at the same distance... am I right in assuming this?..

Gouie,.

You have got that right..

Chris Elliott.

*Nikon* D Eighty + Fifty - Other equipment in Profile.

Http://PlacidoD.Zenfolio.com/..

That's what has me confused about the exposure/focus lock. I just can't think of a situation where this would be useful. If you are following an object, waiting for it to enter your shooting area, I would think that you would want both exposure and focus to adjust as the camera moves. If not you would have to shoot at the exact moment the object enters your pre-determined area..

Having said that, I did do some practicing last night and the panning is a great technique. With a little practice I was able to add the impression of speed to my wife slowly walking through the frame..

Pretty cool stuff but still have tons to learn!..

You've "got it" now....

Prefocus is a good technique, but is more valuable for cameras with contrast AF. Your D40 has phase AF..

Contrast AF is slower and to compensate for that, I often use the prefocus technique. With that, I do a manual focus on an object of interest (pylon, hay bale, basketball net, grass clump, etc.). The camera does NOT even TRY to focus...it just takes the picture when I push the shutter. I also use M-mode (manual exposure) and this eliminates another small delay. With this technique, my goal is to make the shutter lag almost zero, which a fully electronic dSLR (w/o a mirror) can get down to a few milliseconds..

With a mechnical dSLR, I'd not use the prefocus technique, unless the subject is VERY fast. One of the advantages of a mechanical dSLR is that it is faster than an electronic dSLR (everything except the shutter), so I'd use the AF and exposure speed, put it in Continuous Focus Mode, and PAN...then "lead" the action a bit to compensate for the 50-150 millisecond shutter lag (which becomes intuitive)..

Unless you have a good VR lens and steady hands, get a monopod, as it helps keep the camera steady as you pan with slow shutter speed to blur the background..

Gouie wrote:.

Thanks for the replies guys..

Panning. If I auto focus on the object as it is approaching (holdingthe trigger half way) and follow the object, will the camera continueto adjust focus as the object gets closer?.

As far as the exposure/focus lock goes, I've been doing some readingon it but I can't seem to wrap my head around it. My thought is if Ifocus on the object early then use the focus lock feature, will thatprevent the camera from re-adjusting focus as the object gets closeror will it keep the object that you have locked in focus byre-adjusting as it approaches?.

Boy, I hope that makes sense..

Charlie DavisNikon 5700 & Sony R1CATS #25PAS Scribe @ http://www.here-ugo.com/PAS_List.htmHomePage: http://www.1derful.info'I brake for pixels...'..

Apart from using CONTINUOUS focus which you use when pushing the shutter button halfway and then following your subject... there is also focus area - which tells the camera what part of the scene to focus on. A moving object such as a dirtbike you probably want to use Dynamic Focus or if nothing is in front of you, Closest Subject. Lastly, you want to make sure your shutter speed is fast enough to prevent any blur and I'd recommend at least 1/500th of a second. This may be impossible to do indoors if the lighting isn't bright enough unless you have a very fast lens. Good Luck! Post some of your pictures..

Image control:Zoom outZoom 100%Zoom inExpand AllOpen in new window..

... when editing the picture and getting in close, you can see that the focusjust isn't there. The edges are quite blurred..

If the edges of the subject are blurred, but other portions of the subject are sharp, then the problem may not be bad focus: it might be motion blur, or it might be inadequate depth-of-focus (DOF.).

Here's what motion blur looks like. In this example, focus is perfect, and the dancer's body is sharp, but her right foot is blurred because it was moving so much faster than the rest of her body:.

Image control:Zoom outZoom 100%Zoom inExpand AllOpen in new window.

To eliminate motion blur, you need to shoot at a higher shutter speed..

Here's what inadequate DOF looks like. In this example, I used a very large aperture in order to get a fast shutter speed (to avoid motion blur) and one consequence of large apertures is shallow DOF. Note that the dancer on the right is sharp (because I focussed on her) while the dancer just behind her on the left is soft:.

Image control:Zoom outZoom 100%Zoom inExpand AllOpen in new window.

While the above example shows two subjects separated by a couple of feet, one can have cases where even a single subject is too deep (compared to the DOF) for the entire subject to be in focus. Depending on what you want to achieve in the photo, this can be a good thing ....

Image control:Zoom outZoom 100%Zoom inExpand AllOpen in new window.

If you need more DOF to get your entire subject in focus, you must shoot at a smaller aperture...

Often, you're going to have unsharp spots on shots like these, which aren't setup..

In motocross, there's a lot of bouncing around. Although you must pan as someone is moving across the plane in front of you, if they're also bouncing up and down, there's no way for you to pan two directions at once..

Start simple. Slow jumps are relatively easy, as are tight turns. Learn to use the manual exposure mode. Use AF-C, but also experiment with pre-focusing, especially in those single-line slow turns..

You can do it, but it's a learning process. Trying to shoot someone coming toward you in the whoops is probably the most difficult shot in motocross...