Filming Fast things in HDV at DVinfo.net

Brian Luce · October 16th, 2008, 06:40 PM

Can anyone here give me some guidelines for shooting fast moving objects such as racing cars? It's my understanding that the JVC codec struggles with this. Filming a race car might also include a fast pan as the car whizzes by, would that introduce additional complications?

What might be some settings to consider/avoid in terms of shutter speed, frame rate etc?

Adam Letch · October 16th, 2008, 07:55 PM

Brian?
You didn't say whether its the 100 series or 200 series. I shoot horses and helicopters and motox with JVCs 720 25p no probs, just up my shutter to a min of 1/120 to 1/200 sec. Shooting at 50p is of course better, but I wouldn't touch this unless you use a SDI type recording option as it artifacts terribly.

If have to do a real fast whip pan with the subject close to you, you will get the image degrade, but if your panning with it from a distance then it should hold up.

regards

Adam

Brian Luce · October 16th, 2008, 08:10 PM

Quote:

Originally Posted by Adam Letch

Brian?
You didn't say whether its the 100 series or 200 series.
Adam

Hi Adam, it's a 100 series so 60p is SD.

Ben Lynn · October 16th, 2008, 08:44 PM

Brian,

I think that Adam's on the mark with what he said. It's probably better to avoid the 60p SD because of the long codec. I've shot fast objects using 30p-shutter 60 and it can look great if shot right.

Adam mentioned one of the keys; be careful of your pans. If your too close to the cars, don't bother with the pan, make it a slow tracking speed shot. If you have the distance, then go ahead and make the pan.

Basically, you run into problems when the object you're tracking has too much movement within the context of the frame. In other words, you can follow a fast car and it will hold up as long as you keep it centered in the frame (or on the left side or where ever). But make a slip with the tripod during the pan so that the car moves from say the left side of the frame to the right, and then you'll get artifacting within the image.

The shutter will help you dial in the image sharpness you want.

Here's a frame grab from a day at a dirt bike track: http://www.benlynn.tv/Pictures/South...the_camera.jpg

30p shutter-60

You can see that as the rider's coming by, he looks fine. Forget about background artifacts, at playback speed the backgrounds a blur and the rider is in focus and free of artifacts.

Ben

Justin Ferar · October 17th, 2008, 01:01 AM

I'm not sure 480p60 has the same artifact problems as 720p60- has anyone tested it?

I'm thinking that it's not HDV so it should look sweet. It's just that to get it on DVD you have to convert it to 480p30, thus throwing out half the frames- but this is not a bad thing as you still have all those other frames for killer over-cranked slo-mo if you need them.

Brian, if I were you I'd go shoot some trees and shrubs in the back yard and shake the camera around to see if you can break the codec down. I'd try it myself but I have the HD200 which oddly doesn't shoot 480p60!

Brian Luce · October 17th, 2008, 01:44 AM

Quote:

Originally Posted by Justin Ferar

I'm not sure 480p60 has the same artifact problems as 720p60- has anyone tested it?

I'm thinking that it's not HDV so it should look sweet.

I should know this one and to make it worse the camera isn't with me right now, but if I'm not mistaken the SD60p still uses the HDV codec in the HD100.

Stuart Campbell · October 17th, 2008, 02:02 AM

My advice would be to use another format. HDV handles motion terribly. If you have to use HDV DON'T shoot in 50 / 60p. All depends on how important your project is.

http://www.dvinfo.net/conf/jvc-pro-h...gh-motion.html

I learned the hard way. The results are really horrible.

This is one camera which will definitely be staying on the shelf the next time we shoot any motion!

It's worth pointing out that the camera on the above referenced shoot was not panning. It was locked and moving at the same speed as the moving objects it was filming.

I might as well have shot it with a mobile phone!

Ben Lynn · October 17th, 2008, 07:03 AM

I think it depends on the content. Stuart, you emphasized my point, that motion within the frame is bad for the codec. Horses are in constant motion and the results were really bad. I agree with you and wouldn't want to shoot a horse show with these cameras.

Motorsports are more stable and tend to have few moving parts on them so they'll look better. The cars may be going fast, but the only thing really moving in the image are the wheels and the background.

It's a judgement call about what you think will work. But I think that for motorsports the HDV codec is adequate.

Don Bloom · October 17th, 2008, 07:42 AM

het Ben,
how do you know so much about shooting motorsports? ;-)

o|o
\_/

Don

John-Paul Bonadonna · October 17th, 2008, 11:01 AM

Here's a real-world example for you, using the HD200...

http://www.dvinfo.net/conf/jvc-pro-h...g-detroit.html

Ben Lynn · October 17th, 2008, 12:33 PM

Great stuff John-Paul. That clip says it all.

Ben

John-Paul Bonadonna · October 17th, 2008, 04:23 PM

Does it?! What is your verdict? FYI - I used a 250 shutter.

Ben Lynn · October 17th, 2008, 04:56 PM

I still say that the codec and camera hold up for motor sports. The clips shows that under the right conditions (i.e. knowing how to shoot racing) the footage looks great.

John-Paul Bonadonna · October 18th, 2008, 12:10 AM

I think you can get the results you need. If you had to key the footage or something like that, or it was for a Blu-Ray quality demonstration disc, well, you might have issues. But for something that is going to end up as a 16:9 DVD or even broadcast (where satellite and digital cable compression kills you anyway) you'll be just fine.

October 16th, 2008, 06:40 PM	#1
Brian Luce Inner Circle Join Date: Jan 2006 Posts: 2,290	Filming Fast things in HDV Can anyone here give me some guidelines for shooting fast moving objects such as racing cars? It's my understanding that the JVC codec struggles with this. Filming a race car might also include a fast pan as the car whizzes by, would that introduce additional complications? What might be some settings to consider/avoid in terms of shutter speed, frame rate etc?

October 16th, 2008, 07:55 PM	#2
Adam Letch Major Player Join Date: Feb 2006 Location: Perth, Western Australia Posts: 414	Which were you shooting with Brian? You didn't say whether its the 100 series or 200 series. I shoot horses and helicopters and motox with JVCs 720 25p no probs, just up my shutter to a min of 1/120 to 1/200 sec. Shooting at 50p is of course better, but I wouldn't touch this unless you use a SDI type recording option as it artifacts terribly. If have to do a real fast whip pan with the subject close to you, you will get the image degrade, but if your panning with it from a distance then it should hold up. regards Adam

October 17th, 2008, 01:01 AM	#5
Justin Ferar Major Player Join Date: Aug 2006 Location: Larkspur, CA Posts: 378	I'm not sure 480p60 has the same artifact problems as 720p60- has anyone tested it? I'm thinking that it's not HDV so it should look sweet. It's just that to get it on DVD you have to convert it to 480p30, thus throwing out half the frames- but this is not a bad thing as you still have all those other frames for killer over-cranked slo-mo if you need them. Brian, if I were you I'd go shoot some trees and shrubs in the back yard and shake the camera around to see if you can break the codec down. I'd try it myself but I have the HD200 which oddly doesn't shoot 480p60! __________________ www.justinferar.com www.weddingsonfilm.com

October 17th, 2008, 11:01 AM	#10
John-Paul Bonadonna Regular Crew Join Date: May 2008 Location: Windsor, ON, Canada Posts: 47	Example Here's a real-world example for you, using the HD200... http://www.dvinfo.net/conf/jvc-pro-h...g-detroit.html

October 18th, 2008, 12:10 AM	#14
John-Paul Bonadonna Regular Crew Join Date: May 2008 Location: Windsor, ON, Canada Posts: 47	Agreed. I think you can get the results you need. If you had to key the footage or something like that, or it was for a Blu-Ray quality demonstration disc, well, you might have issues. But for something that is going to end up as a 16:9 DVD or even broadcast (where satellite and digital cable compression kills you anyway) you'll be just fine.

October 16th, 2008, 08:44 PM	#4
Ben Lynn Major Player Join Date: Mar 2003 Location: Bloomington, IL Posts: 636	Brian, I think that Adam's on the mark with what he said. It's probably better to avoid the 60p SD because of the long codec. I've shot fast objects using 30p-shutter 60 and it can look great if shot right. Adam mentioned one of the keys; be careful of your pans. If your too close to the cars, don't bother with the pan, make it a slow tracking speed shot. If you have the distance, then go ahead and make the pan. Basically, you run into problems when the object you're tracking has too much movement within the context of the frame. In other words, you can follow a fast car and it will hold up as long as you keep it centered in the frame (or on the left side or where ever). But make a slip with the tripod during the pan so that the car moves from say the left side of the frame to the right, and then you'll get artifacting within the image. The shutter will help you dial in the image sharpness you want. Here's a frame grab from a day at a dirt bike track: http://www.benlynn.tv/Pictures/South...the_camera.jpg 30p shutter-60 You can see that as the rider's coming by, he looks fine. Forget about background artifacts, at playback speed the backgrounds a blur and the rider is in focus and free of artifacts. Ben

October 17th, 2008, 02:02 AM	#7
Stuart Campbell Major Player Join Date: Nov 2006 Location: Hannover, Germany Posts: 400	My advice would be to use another format. HDV handles motion terribly. If you have to use HDV DON'T shoot in 50 / 60p. All depends on how important your project is. http://www.dvinfo.net/conf/jvc-pro-h...gh-motion.html I learned the hard way. The results are really horrible. This is one camera which will definitely be staying on the shelf the next time we shoot any motion! It's worth pointing out that the camera on the above referenced shoot was not panning. It was locked and moving at the same speed as the moving objects it was filming. I might as well have shot it with a mobile phone!

October 17th, 2008, 07:03 AM	#8
Ben Lynn Major Player Join Date: Mar 2003 Location: Bloomington, IL Posts: 636	I think it depends on the content. Stuart, you emphasized my point, that motion within the frame is bad for the codec. Horses are in constant motion and the results were really bad. I agree with you and wouldn't want to shoot a horse show with these cameras. Motorsports are more stable and tend to have few moving parts on them so they'll look better. The cars may be going fast, but the only thing really moving in the image are the wheels and the background. It's a judgement call about what you think will work. But I think that for motorsports the HDV codec is adequate.

October 17th, 2008, 07:42 AM	#9
Don Bloom Inner Circle Join Date: Jan 2003 Location: Chicago, IL Posts: 6,609	het Ben, how do you know so much about shooting motorsports? ;-) o\|o \_/ Don

October 17th, 2008, 12:33 PM	#11
Ben Lynn Major Player Join Date: Mar 2003 Location: Bloomington, IL Posts: 636	Great stuff John-Paul. That clip says it all. Ben

October 17th, 2008, 04:23 PM	#12
John-Paul Bonadonna Regular Crew Join Date: May 2008 Location: Windsor, ON, Canada Posts: 47	Does it?! What is your verdict? FYI - I used a 250 shutter.

October 17th, 2008, 04:56 PM	#13
Ben Lynn Major Player Join Date: Mar 2003 Location: Bloomington, IL Posts: 636	I still say that the codec and camera hold up for motor sports. The clips shows that under the right conditions (i.e. knowing how to shoot racing) the footage looks great.