Using Pro-Sumer for Matchmove montage

[Michael Sechman]

Howdy all,

I know this is too long but I don't have the "speak" to make it shorter so please bear with me.

This is my first time on this forum so if I hurt someones feelings by not playing by the rules I apolgize in advance. This is a very tech area and question/quest.
I have shot some pretty good footage with a cameraman, a Sony F900, shooting at 29.97 progressive (why I don't know but the owner of the Camera shouted on the cell phone to do it this way). I turned out ok. We were shooting from a Jet Ranger over the Oakland, CA Estuary an atrchitectural project. The Camera man had a "Tyler mount with 3 large Gyro's for stabilizing the x,y and z axis. He and the pilot were experienced in this and it turned out to be like a ballroom .dance as they were both trying to be as graceful as I was looking through a monitor directing the center of interest and how close and what zoom length we should use. This was my first time directing a camera man/helicopter. In the end we ended up with some very good 1080p footage. We had to scale it down to 720p becuase of the limitations of our hardware. We are ordering a computer capable of handleling 1080p uncompressed and it is getting really expensive. In the end we had to scale the Matchmove down to 480 to get it on the final DVD production. Crying shame.

So here comes the question (I think the only way I will get my answer is by renting a couple of cameras from Studio B in Berkeley.) but there are so many variables and "hidden" capabilities from the Camera makers I am really confused. Before I got the job I rented the first Sony HDV camera. We really didn't know what we were doing but I convinced the client we could pull this off with a Sony F900 even though the Video Editing Company had a Varicam. They went up to shoot some footage to prove to the client that the Varicam was good enough. They must have given the Varicam to the monkey 'cause it looked really bad. I don't think the monkey knew anything about lighting, exposure and anything variable. The client was kind of like in this dream world so anything we showed him he passed on.

I couldn't stand it so I funded a shoot with a Jet Ranger, Cameraman, Tyler Mount and Sony F900. It cost me 6k for an hour. The kids had to eat rice cakes for a month. We are going after several other jobs like this but the clients are the exact opposite of our first. They have to see it to believe/understand the possibilities. I can't afford another 6K hit right now so I'm looking at HDV. I have heard everything from the Sony Z1U being able to do 1080p with a flip of a switch on a vtr. The best that I can see is the Varicam set correctly and shooting at 720p. What I need is the most stable/still frames. No movies here. I need rock solid frames to use our Matchmove software on. We can make it movie like in post if we want to. It sounds like I shoud be shooting as fast a frame as possible,i.e., 60. I noticed even in the Sony F900 that any sudden camera movement and the frames would blur and we couldn't get a lock on a trackable object or would loose good ones before and after. I can load up some frames and .mov's if someone would care to see them. Our ftp site will hold 400 gigs (got to get another ISP) If I had my druthers I would be shooting a Nikon film camera at 30 frames per second at 1000 shutter speed. Any info will help. I think the best test will be to rent the best cameras sans Sony F900 until Blueray can be used to show my clients what a 1080p movie looks like projected 12' wide to an audience of 30 or more. I think/hope that it will blow their minds.

Some of our work and like most folks it has not be updated for about 3 years.
www.msechman.com
All the best to you all,
Michael Sechman

[Nate Weaver]

Michael,

Ok, I read carefully and I think I got the gist of what your company is trying to do...shoot aerials for 3D architectural renderings?

If it's motion-blur-less video you're after, you're right to shoot progressive (could be done interlaced, but you'd have to render at least twice as many frames, and is easier to mess up). But higher frame rates is not what you're after, you need higher shutter speed.

When you're F900 guy went up, he was shooting 30 whole frames per second, with likely either shutter speed of 1/60th of a second, or 1/30th. A whole lot of camera and aircraft shake can happen in either time span, and the result is, you guessed it, motion blurring. These shutter speeds are what every day TV is shot with, so that's the standard. Do some step-by-stepping on your Tivo and you'll see everything you see on tv has plenty of motion blur. It helps sell the illusion.

The way to make less motion blur in each frame is to shorten the length of time the camera is accepting light for each frame. You can shoot with, say, a 1/250th shutter speed. Your idea of upping the frame rate has the side effect of also shortening the shutter speed, but you can get where you want to go without shooting all those unnecessary frames.

The problem with this is that it can make for some unnatural looking video. Remember in Saving Private Ryan, the beach battle scenes? Everything is jittery and looks a little bit too sharp and nervous? That's what higher shutter speeds do. Probably not a good sales tool.

Shutter speed can be manipulated in-shot. Could you start out each aerial move with a high shutter speed (to aid the matchmove), switch after a second to a normal shutter speed and complete the move, and then end with a high shutter speed (for good matchmoving measure)?

The other way to minimize aircraft motion blur is to shoot these with a true gyro head like a Spacecam rig as opposed to a Tyler mount (I assume you used a Tyler middle mount)? But this could easily be double what you already spent.

If you're shooting for standard def DVD, even a progressive mode HDV camera can help you out without the expense of Varicam or F900 (although those cams will lend a polished look to your product). A Panasonic HVX could help you out, so could a JVC HD100. I think you learned the hard way that you can make horrid video with an expensive cam just as easily as with a $5k cam.

[Tony Tremble]

It is not a case of shooting at a high frame rate is is a question of capturing footage that won't confuse the trackers in the software. You MUST control camera shake and motion blur no matter what camera you use. High frequency shake and a lot of motion blur will be tough to matchmove as at the very least the inseted object will slip and slide on the background plate.

To complicate matters HDV compression has the effect of increasing the motion blur of fast moving objects so even if you use a high shutter speed movement of fast objects will still blur. So if you go down the HDV route you'll have to work within its limitations.

Having said that a good tracker should have a pretty good idea how to cope with a reasonable amount of motion blur and still give a reliable track.

What matchmove software are you using?

Post a short clip so we can see why the track is not working.

I'll be glad to help with a bit more info. I should imagine this thread will be moved somewhere else.

TT

[Philip Williams]

Just a thought, have you looked at the HVX200 for this type of work? 1080P is definitely softer than the V1, but it does use an intraframe codec and supports 720P/60fps. Search around here and on dvxuser.com for posts from Jim Arthurs, he's done some pro VFX shots with the HVX and they're very, very impressive. Especially see if you can scare up the Remax commercial he did.

You might also look at the XLH1 (or the XHA1 if you can find one that isn't pre-sold). The 30F mode on it looks nicer than its raw resolution count would indicate and Canon's HDV implementation is very robust (and in fairness, the V1's implementation is bound to be improved over Sony's 1st gen cams).

Oh yes, the V1 isn't out until December, so that might be a factor. And if early enthusiasm is any indication, it'll probably be hard to hunt down for a while after that.

www.philipwilliams.com