I think we need to put this into perspective. The EX1 is probably the most expensive camera with autofocus. Take the next step up and you don't get it at all, I don't think there's even a SD 1/2" camera with it.

Think it through, what do you want the AF to focus on. You can easily get shallow enough DOF where the most visible edge might not be where you want focus anyway, do you want to focus on the talents ears, eyes or nose. The first option will be the easiest for the AF to lock onto, the latter could be a problem and the eyes might be difficult too as it tries to find an edge. My DSC has a centre focus marker which is handy but hardly useful with moving images. Even more of a problem is with 16:9, it's quite common not to have the subject centre frame.

You can solve this to some extent with a rangefinder but without a scope / laser marker how do you know what it's measuring the distance to. Great if you're shooting set pieces, for gun and run largely useless.

I'm dead set hopeless at focussing and I wish there was a magic solution but I bought an EX1 knowing I'd need to hone my skills. I've mostly shot with a PD170 in the past or hired a good cameraman who could do the three ring dance while he danced around the talent.
The good news is if you're shooting exteriors you've probably got enough light so you can iris down and get enough DOF so focussing is less critical, as others have said staying wide will also help. One thing to check regularly is backfocus. The old zoom in, focus, zoom out trick will bring you unstuck if the backfocus is out.

Bob,
I thought I made it fairly clear that I don't normally use AF.
I'm not trying to make excuses for focusing a camera.

It's ovbvious AF can't read your mind on what you want in focus.

The thread was to understand why the EX1 AF is hunting even though the conditions are optimal. I just would like to know if the problem is across all cameras, or tied to just mine. I layed out a simple test for those who have the camera.

True about back focus. I've been nailed on that several times with my JVC HD100.
Ideally, you need to check it before any shoot and check it during the day, especially if there are temp changes.

Fortunately, no need to worry about back focus on the EX1, although, I hear there is a service menu option for adjustment in the factory or service.

Not fast. I was working through features last evening and auto focus was one. I'm used to giving the FX1 a jab for quick auto focus but on the EX I thought nothing was happening. So confirm slow and hunting, but not having noticed this thread I didn't quantify. Too slow to grab focus for run & gun but haven't checked how capably it tracks dynamic focus (ie. full auto focus). Peaking looks good for manual focus and so far I seem to be able to focus using the VF.

Thanks Serena.
When you get a chance, try the test I mentioned in this thread. I'd be interested if it shows the same symptoms.

Yes, the EX1 peaking really works great. The LCD is capable of making decent focus judgements. I was very surprised.

I was referring to the WA lens (add-on) made especially for the EX-1 (VLC-EX0877). There are or will soon be third party WA lenses available, although they will probably not be able to take advantage of the CA (chromatic aberration) reduction capability the Sony combo offers. In practice, no one yet knows how well this works.

Steven,
sorry mate I thought we'd already determined that your camera was performing much the same as everyone else's.
I just did a pretty quick and sloppy test as I don't have a good set of sticks at hand and it's getting dark. However what I did notice was panning along the edge of a table at an angle so the distance to focus slowly increased the AF would suddenly loose the plot and go through a complete refocus.
First time I tried I had Macro on, turning it Off seemed to help but it still did the same dance just not quite as dramatically. I was panning quite slowly but hand held, perhaps someone with a good tripod and better setup should repeat this test but I'd say you certainly cannot rely on the AF to do a rack focus for you. The speed to find focus was around 2 seconds and I didn't notice any hunting once it'd found focus but that wasn't under good test conditions but certainly nothing unlike what you'd encounter under gun and run where you just have to get the shot and anything can happen.

My slightly better times might be because the camera was in 50i.

Thanks Bob,

This is why I am interested in the test I posted.
My camera when stationary and staring at high contrast objects in good light will nail focus for 1 second and then start to slightly move in and out
as if it did not find it. It should disable servo when it finds its peak.

While it's auto focusing, I can see where the peak is using the peaking function. I'm not sure why it does not disable servo once it rolls over the peak. I understand the camera should continue to adjust AF if the camera is moving across a different focus plane, but in this case it's stationary.

You're not seeing this, so this is starting to confirm my original thoughts that there's a problem with my camera.

"I suspect the slow autofocus is simply the price we have to pay for having a true mechanical lens - it's got to be much easier to make a fast, smooth and quiet autofocus when you don't have to have the lens elements coupled to gears meant to be turned by a large outer ring."

This is the reason I suspect. Most all the other AF cameras use an inner-focus system. Think of a lens carried within a speaker voice coil. Near instant response because there's almost no mass.

The question of the INDICATED hunting -- perhaps the VF read-out shows the sensor output. But, also perhaps, this signal is not being sent directly to the lens servo. Perhaps a "damped" version is sent to the servo. So, when you see the "hunting" do you see the mechanism moving? Or, do you see the focus change on a monitor?

Assuming it does hunt -- then the Push-to-Focus button is the key. I tend to hold it down for a second or two. The other is to use the Assist function to rapidly get close and manually find the final focus.

Steve,

On the EX1, I've never seen the outer focus ring move with the AF, regardless on how far focus was off. I'm assuming this is all done via an interval servo driven optic?

Well,
After more experimentation using all image modes, I did find that 1080 60i was the most stable. I was under the assumption, since the AF is time sampled based and needs a high frame rate that 720 60P would be sufficient.
Well, I was wrong! 60P hunts and rarely locks.

This is odd, when I tired the SAME tests yesterday, 1080 60i seemed also unstable; although, most of my testing was on 720 60P.
So I guess the bottom line is you can not use progressive, even at 60P when using AF mode?
From previous AF cameras I know this is true, but I sure thought 60P would of worked well enough.

Resurrecting old thread...
 

...but I want to confirm Steven Thomas' EX1 focus hunting behavior on my camera.

On a tripod, if I move the small switch to manual focus, the dof display is stable. If I thereafter press the AF button, the DOF display hunts continuously. I was expecting a one-time movement from this.