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Author Topic: Stabilisation in software  (Read 2255 times)

KevinA

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Stabilisation in software
« on: November 05, 2011, 09:04:45 am »

Hi,
I'm trying to get it so I can shoot aerial footage and get it smooth for iPad, net, business presentation etc. I'm using a DSLR's I also use a couple of gyro's which helps. With the help of After Effects I'm 85% there. What I can't get rid of is a ripple like effect. The best way I can describe it is like holding a card in your hands and quickly twitching it about the middle so top and bottom come and go towards you.
Is this the infamous cmos rolling shutter effect?

Kevin.
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feppe

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Re: Stabilisation in software
« Reply #1 on: November 05, 2011, 09:27:15 am »

Hi,
I'm trying to get it so I can shoot aerial footage and get it smooth for iPad, net, business presentation etc. I'm using a DSLR's I also use a couple of gyro's which helps. With the help of After Effects I'm 85% there. What I can't get rid of is a ripple like effect. The best way I can describe it is like holding a card in your hands and quickly twitching it about the middle so top and bottom come and go towards you.
Is this the infamous cmos rolling shutter effect?

Sounds like it. There's software to alleviate that problem as well. No idea which fix should be done first, though.

KevinA

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Re: Stabilisation in software
« Reply #2 on: November 07, 2011, 04:22:17 am »

Are some cmos chipped cameras better at dealing with the wobble than others. I get the same with 5D and 550D. Would a dedicated video camera do a better job?

Kevin.
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feppe

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Re: Stabilisation in software
« Reply #3 on: November 07, 2011, 12:42:05 pm »

Are some cmos chipped cameras better at dealing with the wobble than others. I get the same with 5D and 550D. Would a dedicated video camera do a better job?

I have no first-hand experience, but Panasonic AG-AF100 supposedly suffers noticeably less from rolling shutter.

It's to do with how the sensor reads the data, line by line. There are rumors of a universal shutter from Panasonic coming out in the near future, where the sensor data is read at once. I'm sure others are working on it as well.

bjammin

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Re: Stabilisation in software
« Reply #4 on: November 07, 2011, 01:04:25 pm »

I've been shooting from helicopters and airplanes for more than 30 years and I know there is no substitute for dedicated helicopter mounted, gyro stabilized systems. That being said, there are quite a number of ways to help yourself, including camera selection.  First, a good pilot in a smooth ship makes a huge difference.  Helicopters will produce better footage if you fly low, though fixed wing aircraft can yield great results when at higher altitudes (say above 1,000 feet or more on wide shots.)  Flying in the early morning before winds have picked up also really helps.

With regard to camera selection, rolling shutter is a big problem when there is lots of motion.  All CMOS cameras seem to suffer from this problem in one way or another.  I've compared both professional CMOS and CCD cameras, DSLRs, GoPro, and consumer grade video cameras.  All will produce better results with gyro stabilization and smoother flying.

If you live in an area with good professional video rental houses, you can get something like a Tyler Mini Gyro to greatly enhance the smoothness of the video.  If budget is of concern,  I've had good luck mounting a DSLR on a mono pod which I've set on the seat cushion of the aircraft to isolate the camera from vibration. Shoot as wide as you can to slow the motion down as well.

One really critical issue is the shutter speed you choose.  If you have a camera that can shoot 60 FPS and you can play the footage back at 24 FPS,
it will yield a slow motion effect that really helps smooth vibration.

If you have a chance, you might view this video I shot last month and watch the aerials carefully.

http://www.youtube.com/watch?v=j-xCALXBUAI

We hit a really bad windy day and the helicopter was slammed back and forth constantly.  I was using a Tyler Mini Gyro and a large Panasonic professional video camera.  Even so, the footage was too bumpy to use as it was.  I had to stabilize the footage in Adobe After Effects using the "warp stabilizer" function. It did an excellent job, but if you look closely, you will see momentary blurring as the camera shook so violently that there was motion blur in the captured footage.
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KevinA

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Re: Stabilisation in software
« Reply #5 on: November 07, 2011, 02:03:47 pm »

I've been shooting from helicopters and airplanes for more than 30 years and I know there is no substitute for dedicated helicopter mounted, gyro stabilized systems. That being said, there are quite a number of ways to help yourself, including camera selection.  First, a good pilot in a smooth ship makes a huge difference.  Helicopters will produce better footage if you fly low, though fixed wing aircraft can yield great results when at higher altitudes (say above 1,000 feet or more on wide shots.)  Flying in the early morning before winds have picked up also really helps.

With regard to camera selection, rolling shutter is a big problem when there is lots of motion.  All CMOS cameras seem to suffer from this problem in one way or another.  I've compared both professional CMOS and CCD cameras, DSLRs, GoPro, and consumer grade video cameras.  All will produce better results with gyro stabilization and smoother flying.

If you live in an area with good professional video rental houses, you can get something like a Tyler Mini Gyro to greatly enhance the smoothness of the video.  If budget is of concern,  I've had good luck mounting a DSLR on a mono pod which I've set on the seat cushion of the aircraft to isolate the camera from vibration. Shoot as wide as you can to slow the motion down as well.

One really critical issue is the shutter speed you choose.  If you have a camera that can shoot 60 FPS and you can play the footage back at 24 FPS,
it will yield a slow motion effect that really helps smooth vibration.

If you have a chance, you might view this video I shot last month and watch the aerials carefully.

http://www.youtube.com/watch?v=j-xCALXBUAI

We hit a really bad windy day and the helicopter was slammed back and forth constantly.  I was using a Tyler Mini Gyro and a large Panasonic professional video camera.  Even so, the footage was too bumpy to use as it was.  I had to stabilize the footage in Adobe After Effects using the "warp stabilizer" function. It did an excellent job, but if you look closely, you will see momentary blurring as the camera shook so violently that there was motion blur in the captured footage.
Agreed nothing like getting the basics right.
The Tyler mini is that the pogo stick  with two KS4's inside isn't it?
I've been working on a few designs with more and bigger gyro's, it's that cmos wobble that I can't make much headway against. I don't want to be limited to wide shots from a slow helicopter.

Kevin.
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bjammin

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Re: Stabilisation in software
« Reply #6 on: November 07, 2011, 03:18:33 pm »

The Tyler is indeed the "pogo stick" thing.  It works pretty well but nothing like a dedicated aircraft-mounted device.  One thing I will say, my Panasonic HPX-300 video camera (CMOS) seems to do a better job of avoiding the dreaded "jello-cam" effect. I've compared it to a Canon 5d, Nikon D7000, GoPro, and a small Canon HFS100 Camcorder.  For some reason, I see much less problem with the Panasonic. I wonder if the CMOS wobble will be lower if you set the DSLR to a much higher shutter speed?
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