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Bill Prouty April 30th, 2004 04:43 PM

Filming an action sequence on DV
 
This July I am filming a five-minute high-speed chase through the streets of London and would welcome any advice regarding camera selection and capturing action sequences on DV. My apologies in advance for the mixture of questions.

Here are my constraints:

1) The film must be broadcast on 16:9 anamorphic PAL and distributed on 16:9 anamorphic PAL DVD. There is also potential for a 35mm blow-up.
2) 90% of filming will occur with only natural summer daylight. The remaining 10% will be shot at night using light from streetlights
3) The film has no dialogue and all sound design / effects will be recorded after the picture is locked.
4) The film is 75% action (200 cuts) with many handheld and POV shots. Static shots will have significant motion within the frame.
5) The camera must be light enough to operate with one hand.
6) The project must be edited on FCP 4. Fire, Flame After Effects and Magic Bullet are available for the final conform, grade and deartifact.


Here is my GENERAL shooting approach:

1) Matte box and ND filters to address daylight contrast
2) “cinematic” composition, avoiding whip pans/tilts in particular
3) wide angle lens for greater depth of field and accentuation of speed. Possible fish-eye and teleconverter to mix things up.

I’m interested in any techniques to overcome the “stutter” or “strobe” effect so often associated with deinterlaced video. Experiences with shutter speed in relation to motion blur would also be very useful.

Should I film in progressive scan, or shoot interlaced and use software to deinterlace later? 24p, 30p or 60i? Has anyone had any luck "overcranking" DV using some sort of software interpolation on 60i?

What camera do you believe is best suited for the project given my shooting restraints? At the moment I am particularly interested in a comparison of the Panasonic DVX100A (25p PAL) and the JVC-HD10U (30p). In relation to the Panasonic, if I use an anamorphic adapter, does this mean I cannot shoot wide angle? I’ve also heard mixed reviews about the cameras 16:9 “squeeze mode”. In relation to the JVC, I’ve read that the 30p to 25p/24p conversion can be a nightmare, and I am concerned that the MPEG compression format will show significant artifacting when forced to cruch very active frames. I’ve also seems that the HDV post-production workflow has not been perfected. Still, the greater resolution would excellent if the film is blown up to a 35mm print.

Much of the chase will be filmed by an operator on rollerblades. Our tests have come back with an excellent floating sensation, but a high frequency buzz is being transmitted from the wheels through to the operator's arm. Does anyone know of dampener to reduce this buzz? Something like a rigid hoop connecting to a central camera mount with elastic chords?

Any other experience / advice on capturing an action sequence on DV would be extremely helpful.

Happy Trails,

Bill

Shawn Mielke April 30th, 2004 06:09 PM

- Yes, the DVX does sound like the cam for what you want to do, offering you the most choices in how to treat motion, although being able to convert to either 30p or 24p at any given time, later on, via software, does seem to be an issue. It sounds like you somehow need to do test shoots/processing for all of this, first. Have you seen this "buzz" in 30 or 24p? Did you shoot your tests on the actual surface that you'll be filming? Do roller blade wheels differ, and is there a wheel that would work better/best? Handheld camera stabilizer?

Fastshutterspeeds seem to be very much a part of the action film vocabulary these days, is that true? I find it interesting and effective.

Dan Euritt May 1st, 2004 02:51 PM

i think that the absolute worst thing you could do would be to try converting the frame rate to pal... shoot it at the same frame rate you want to end up with.

panning would be a definite no-no.

i don't see the point of having a camera man on rollerblades... why not shoot out of a camera car instead? you'll go a lot faster, and it'll be a lot smoother.

your scenario begs for the use of some kind of an on-board camera... maybe one of those multi-suction cup rigs, or bolt it to the roll cage, etc.

also take a look at that "ronin" movie... great chase scenes in europe, at film frame rates, i'd be duplicating some of those shots.

Bill Prouty May 1st, 2004 03:57 PM

Foot chase
 
Thanks for the thoughts.

I should add some clarification.

The action sequence is a foot/bike chase through public areas of London, so the operator on rollerblades is being used instead of a dolly. I will test various wheels to see if that helps with the buzz.

I'm still torn between the two cameras.

Bill Pryor May 1st, 2004 07:54 PM

I would go with the DVX100a, especially since you're in a PAL country. The JVC may record to an HD format, but remember that it's still a single chip consumer camera. I think any of the 3 chip 1/3" chip cameras will give you better results.

Since you're doing hand held work from roller blades, I would eliminate the matte box and keep the camera as light and balanced as possible. It already has built in ND filter, so you don't really need another one. That has nothing to do with contrast. You can adjust settings in the camera to help out with that (read the manual and do tests first).

You might also want to consider a Marzpak (www.marztek.com, I think is the web site--if that's the wrong spelling, do a Yahoo search under Marzpak). Basically, it is a vest the operator wears with an upside down J-shaped plastic support tube that goes over his head. Inside the J-tube is an adjustable bungee cord. The camera mounts to the cord, and the elasticity of the cord allows the camera to "float" and absorbs vibration. It's sort of a poor man's Steadycam. They sell for around $400 (USD) in the U.S.

For daytime shooting, you might experiment with higher than normal shutter speeds, such as 1/125 or 1/250, assuming there is enough light.

Since you may go to film, you need all the resolution you can get, so using the electronic 16:9 mode of the DVX100a is probably not the best option. You can purchase an anamorphic adapter and that will give you better quality 16:9, although the image in the viewfinder will be distorted during shooting. Some people have used the electronic 16:9 on Sony cameras and have done transfers to film successfully, but I haven't heard of anyone doing anything like that with this camera. The best thing to do would be shoot a test and send it to the lab you plan to use for your transfer. I'd shoot a test with the camera's electronic 16:9 and with an anamorphic adapter and see if there is a serious difference. At any rate, it is essential to discuss the project with your lab first. Since you're in London, Swiss Effects would be a good place to start. In fact, I would talk to somebody at the lab before buying anything. Those guys have seen everything and can probably give you some tips that may save you a lot of grief.

I'm not sure what you mean by "buzz" from the wheels. Obviously the camera's mic will pick up the sounds of the wheels. If you want other sounds, use a wireless mic and put it on the subject being shot or something like that.

The smartest thing to do, if possible, would be to rent the camera you're interested in for a day and shoot some tests.

Shawn Mielke May 1st, 2004 07:59 PM

He's doing all sound in post, so I think he's using the word "buzz" in visual terms, like an undesirable vibration in the image.

Bill Pryor May 1st, 2004 08:08 PM

Oh...I guess buzz is British for vibration. OK, I get it. In that case, my recommendation of the Marzpak might be useful. I think a real Steadycam or Glidecam would put the roller blader too off balance.

Shawn Mielke May 1st, 2004 08:33 PM

Frame rate and/or shutterspeed would affect something like that, also, I should think, for better and worse?

Adam Burtle May 2nd, 2004 12:36 AM

we shoot on rollerblades all the time.. never an issue.. maybe it's his blades?

if your budget includes flame for post, does it also possible include rental of a pro cam? anything that can shoot 60p fps can be slowed nicely to 24p. just a thought.

Bill Prouty May 2nd, 2004 07:58 AM

Thanks for the thoughts.

I had a look at the MARzPAK and it looks interesting. Has anyone shot with it?

The "buzz" I'm referring to is a high frequency image vibration, that would probablly go unnoticed on DVD or video projection... but could be annoying when blown up to film. The frequency is so high that the optical stabilization cannot cannot correct for it... at least on the cameras I've played with so far. I'll play around with a mixture of surfaces and wheels until I find the right mix.

Can you mount a telephoto or wide angle lens in front of the anamorphic adapter? Has anyone transferred an image to film captured by the DVX100a in 16:9 THIN squeeze mode? Has anyone seen a comparison of the anamorphic lens image vs the 16:9 squeeze?

My roommate works for a post house... thus my access to all the fun finishing kit. I haven't done much research, but it seems that the pro cams are still a bit to bulky for what we're trying to do.

Looks like I still have to do some tests, but thanks for the tips.

I should have something to show around October.

Bill Pryor May 2nd, 2004 12:12 PM

I've shot with the Marzpak. It's a useful thing in certain circumstances. I think it might help out your situation, but you wouldn't know till you tried. What works best for me when I use it is to tighten up the cord very high, then put downward pressure on the camera when shooting out to the side, about waist high. It's also nice for lower angle shots too. It's not a Steadycam, but it can help smooth out things. I'd think it would help with your vibration problem, but again, you'd have to test it out.
I don't know if you can put a wide angle or telephoto adapter on the anamorphic adapter. My guess is that if you did, you probably wouldn't be able to zoom back very wide when using it, because of vignetting.
One nice thing about the DVX100a is that it has a wider angle lens than the other 1/3" chip cameras in its class.

Hugh DiMauro May 3rd, 2004 11:54 AM

My Two Cents
 
Check out www.Stickypod.com. AWESOME suction cup camera mount for a fantastic price. I've come to the conclusion that you should shoot interlaced and de-interlace on your editing software. The theory seems to be that you should keep your original image acquisition as clean as possible. Which brings me to the anamorphic squeeze function in cameras. That seems to reduce resolution so might I suggest matting off your location moitor with tape or using the Canon XL1s which has the viewfinder 16 X 9 guides to you can frame it in 16 X 9 and letterbox in post with a matte. As far as fast moving dolly shots, shooting from a convertible or out the sliding side door of a van is great. The van method allows you to keep the cam on a tripod which can, believe it or not, give you pretty steady results.

Just a thought.


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