Shooting High Speed Action (Autoracing) with EX1 Advice Needed

[Bob Jackson]

Hi
This is my first post here.
I have been trying my EX1 shooting traffic on a freeway.
They are coming towards me at a 30º angle. Approx. 70mph.
1080p-30
Shooting 1/125 sec, action is blurry until shutter angle is 45º or less.
Shooting 1/60 sec , action is blurry until shutter angle is 22º or less.
I am going to try 1080i-60, and 720p-60.
I am very disappointed with my results.
I have been using camera on full manual.
Will try manual aperture and auto focus, which i dread.
Perhaps i have a setting wrong somewhere.
Any advice would be greatly appreciated.
Bob

[Craig Seeman]

You'll get much better temporal resolution at 1080i60 or 720p60. 60 images a second is better temporal resolution than 30. That should be obvious.

Faster shutter speed will give you sharper individual frames but you're get the "Saving Private Ryan" motion at some point (steppy). There's a juggle between sharp individual frames and fluidity of motion (motion blur) and the choice is aesthetic.

Why would you use autofocus unless you were tracking an individual car with a constantly changing focal plane (maybe that's what you're doing)?

[Steven Thomas]

Bob,
Post us an example of what you are seeing. Use vimeo to post.

This is the ONLY way anone can help you.

[Jason Bodnar]

For Motocross Racing I shoot 1/500 or even 1/1000 as long as I have enough light and that is in HQ 1080 30p and 720 24p set to 60fps for slo-mo these high shutter speeds sharpen up the frames and allow for post motion blur if needed. No stepping for me but certain types of pans could introduce stepping with these high shutter speeds, I try to avoid those...

[Perrone Ford]

Might also be helpful if you give us an idea of what you are TRYING to achieve. Shooting high speed action, whether with a still camera, motion picture camera, or a video camera, requires skill and understanding.

If you take a hard look at feature films that have chase sequences or highway scenes, you'll begin to note how they are filmed and why they are filmed that way. For an EXCELLENT example of this, watch The Matrix part 2. The highway chase scene is an absolute lesson in filming automotive action. For other examples, try Ronin, or Grand Prix. Or the original Italian Job.

[Brian Karr]

Jason,

Curious about your experience with 30p vs 60i? I havn't had the chance yet to really compare 30p vs 60i rendered to 30p with high speed action. Any comments?

[Nick Stone]

Hi Perrone,

Can you shed some light on what you mean? I don’t have these films in front of me and would like to hear your thoughts.

If I have to chase something, lets say a horse chase up and down a paddock and it moves out of focal plane I use auto focus which I hate doing. Manual focus is very hard to get right for me in this instance. I’m using a Sony 1/3 chip Z1

Nick

[Bob Jackson]

Originally Posted by Jason Bodnar

For Motocross Racing I shoot 1/500 or even 1/1000 as long as I have enough light and that is in HQ 1080 30p and 720 24p set to 60fps for slo-mo these high shutter speeds sharpen up the frames and allow for post motion blur if needed. No stepping for me but certain types of pans could introduce stepping with these high shutter speeds, I try to avoid those...

I have used digital high speed shutters on my old betacam and the strobing effect is not what i want.

[Perrone Ford]

What I mean is this:

There are only a couple of viable ways of filming high speed action and doing it well.

1. Use an adequate depth of field to maintain critical focus of the subject performing the action. If you want to film cars in a chicane on a track, use enough depth of field so that the cars entering, progressing through, and exiting the chicane are in focus without adjustments.

2. Use pre-focus so that cars come into a zone of focus and leave it again. I see this one often when one wants to get a tight shot of a driver in action, or have some critical piece of film in focus. It adds a surreal effect and is used a lot with slo-mo.

3. Use a chase vehicle. This places the viewer in the action. The blur of the background and static objects offers the sense of motion we want. We can frame tight or loose and still get that sense

4. Use longer shots at wider angles. This is the classic establishing shot, but can offer a wonderful sense of motion at about the 28-35mm focal length. We get our subject and enough surrounding elements to really heighten the motion. John Frankenheimer was a master at this, and it's one reason Ronin stands out for it's car chase scenes.

If we look at feature films that have car chase scenes, we tend to see all these techniques and a few others (cranes, car dollys, etc.) used. But the cuts tend to happen quite frequently. 2-5 seconds and out. This is why I suggested the highway chase scene from the Matrix 2. It's a 15 minute or so sequence that uses nearly every technique in the book, and to great effect.

In terms of "the look", there is certainly a difference between allowing the natural motion blur that occurs at 24 frames with a 180 or 90 degree shutter, and the very staccato or stroboscopic feel of a 22 degree shutter or something similar. It really does depend on what feel you want.

Originally Posted by Nick Stone

Hi Perrone,

Can you shed some light on what you mean? I don’t have these films in front of me and would like to hear your thoughts.

If I have to chase something, lets say a horse chase up and down a paddock and it moves out of focal plane I use auto focus which I hate doing. Manual focus is very hard to get right for me in this instance. I’m using a Sony 1/3 chip Z1

Nick

[Jason Bodnar]

Brian, I love shooting progressive... Every frame is usable... and I love to be able to capture stills from my video..I have not done extessive testing 60i vs 30p


Bob, I am not getting any Strobing with 1080p 30 nor do I see any with 720p 24 overcranked at 60 for slo-mo. I am not familiar with the older Betacam...but The EX1 is fine with 1/500 and 1/1000 as long as you have suffcient light.

Now if I shoot 24p it is strobing for sure and I do not like 24p for this reason...

Bob, also I would not use Autofocus, unless you have upgraded to FW 1.11 as the lock on seems to have improved along with the drifting of focus or hunting so to speak. it was horrid until I upgraded now it seems to be improved...but I still go manual on everything.. unless in a Heli.