Would the Focus Limit Switch have helped

[nigel_farmer]

<p>I have done a couple of shoots of waterskiing and wakeboarding recently from the back of a speedboat with a D7100 and 70-300 vr for the first shoot and then my new 70-200 f4 on the second (thanks again for the advice) . <br>

I was using AF-C, dynamic-area AF (21 points initially then 9) and the centre AF point or 1 above/below and nailed the vast majority of shots focus-wise, but in some cases the AF was fooled by spray from the boat coming into the frame. I have never thought of using the focus limiter other than with my macro lens, but I wondered if I could have prevented these shots or some of then being out of focus if I used the focus limiter, since the spray would be within 3 metres? Or would the focus just be somewhere else, but likely not on the subject or the spray? Could I have done something different. </p>

<p> </p>

[john_demarco]

Although my camera(D200) doesn't have an autofocus system as good as yours, I have recently set mine up to use just

the center point for focus. I have been shooting a bunch of soccer, and was having a similar issue as yours when other

players would be near the main player that I wanted in focus. I have also been shooting some auto racing in the past few

weeks. In both situations I have been getting what I think is better results, and more keepers. I use my AF-S 80-200 with

the focus limiter NOT set to full. As far as I know, I believe the limiter is more for focus speed rather than sharper focus,

but someone else could probably explain it better than me.

[elliot1]

<p>Custom setting A3 set to 'LONG' would likely resolve your issue. The focus limit switch would not.</p>

[anthony_bez]

<p>Nigel,<br>

If you are shooting from the boat, switch to manual focus. The skier or rider will stay the same distance from you.<br>

<br />Also you can lock on the subject with AF when the rope goes tight, then switch to MF. Or the best method is to set your AF button to focus, and disable AF from the shutter button.<br>

<br />Cheers</p>

[nigel_farmer]

<p>Thanks for responses. Will look into custom setting A3. I was using AF-ON to focus. I did think about switching to MF.</p>

 

[anthony_bez]

<p>Nigel,<br>

Obtain focus with AF-ON on the face of the skier, rider, when the rope goes tight. You have no need to refocus unless he shortens the ski rope. <br>

The hard contrast of the water spray will fool the AF of your camera whatever setting you use. <br>

<br />Cheers</p>

[john_r._fulton_jr.]

<p>I'm with Anthony Bez on this. Forget AF. Just manual. The person is on a fixed length rope. Should be fairly (!) easy. If it's boat to boat then I'd still use manual. Too much movement in both boats plus skier to proper AF it. BTW, if your lens has VR you probably should turn it off. I don't think it likes being 'on' in something moving altho I could be wrong on that. Good luck with your shoot.</p>

[john_demarco]

Hey Nigel, here is a thought for you. If your VR is on, is it set to the active setting? I use the 70-300 VR often, and In the

lens' manual it mentions if you are shooting from a moving conveyance to set VR to active.

[nigel_farmer]

VR is one of those things that I often

leave on and forget to switch off. In this

situation I was shooting at 1/1000 to

1/1500th of a second so shouldnt have VR

switched on. With VR on I noticed that

images where not as clean and up close faces

seemed a bit noisy, but no such problem with

VR off.

When the wakeboarders jump, then you get a

fair amount of slack in the rope and the

boat may slow down a bit too. I tried using

a higher than centre AF point to avoid the

spray, but when they jump this puts them too

close to the top of the frame for my liking.

preselecting focus using af-on is a good

option for the normal shots and the skiers,

but perhaps not for the boarders when they

are doing big jumps and turns.

[john_demarco]

Hmmm, interesting. Have you tried using just the center point and following the wakeboarders when they jump? Kind of

like a vertical panning shot.