hd video from the airplane

How to shoot best high-definition video in various specific situations, regardless of camcorder model. Accessories: tripods, stabilizers, lights...
shammah98
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Joined: 02 Aug 2010 00:43
Location: Portland, OR

hd video from the airplane

Post by shammah98 »

Hi,
I own a Sony CX-7 I purchased to shoot short aviation videos. These are from single engine, non pressurized airplanes. So as you can imagine, there's a fair amount of noise and vibration. I have noticed that I cannot get a clear image/video with this. The video always comes out looking "hazy", blurry, and sometimes, depending on how fast the engine is running(?), it sometimes will have a "wavy effect" to it.
I do have it set on manual (infinity) focus.
Is there anyway to get clearer images in such a setting?
On the ground, shooting home videos, the camera works fine. It's not as sharp/bright as some other cameras I've seen, but it at least looks like hd video. The stuff im getting in the air looks a lot worse than SD.
thanks!
Ernest
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Doughie
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Re: hd video from the airplane

Post by Doughie »

Hi Ernest

The reason the video looks 'wavy' will be two things :
1) optical image stabilisation USUALLY works really well with almost all situations. But... high-frequency vibration is one situation when EIS (electronic Image stabilisation), rather than OIS (Optical Image Stabilisation) tends to work better. your Sony CX-7 has OIS so the vibrations you get from a turbo-prop plane probably is the sort of vibrations where OIS doesnt work as well as it should. The engine revs will affect the shaking because of harmonics. Materials will vibrate more when shaken or virbrated at certain frequencies. There will likely be an engine rpm range that shakes the airframe at a particularly bad frequency which your cam's OIS is really not equipped to handle. It at all possible, try borrowing another cam that has EIS, not OIS.

2) Your cam has a CMOS sensor and these sensors can be susceptible to "rolling shutter" image problems that may manifest themselves as a 'wavy' or 'jelly like' image. This is often a problem with CMOS sensors. It does vary amongst different camera models.

So a combination of these two things is probably resulting in your problem. To mininise rolling shuitter problems you really need to try to film in such a way that reduces objects crossing the frame from left to right (or right to left) too fast. I am not sure what exactly you're filming but try panning so that content is not moving nearlyt as much sideways. Experiment with that.

Vibration-wise, i would experiment with turning the OIS image stabilisation OFF (or try a different OIS setting - often these cams have two ro 3 different settings for the stablisation). The problem with a light plane is the whole airframe is vibrating so really I would advise handholding with as much of "YOU" in between the vibrating airframe and the camera. The human body can actually act as a vibration damper. SO i wouldnt rest the cam on a seat-back or have it braced against the wall / fuselage. I think that will make thing worse. Try handholding, brace yourself against the place and pan so that the ground (assuming you're filming content OUTSIDE of the plane and i would think so as you said you set focus to infinity) is not moving fast laterally across the frame.

End of the day, it's a hostile environment for getting good images. Experiment with the OIS turned off, panning to minimise content movement, particularly laterally, and experiment with soft vibration-absorbing materials that you might want to 'wrap' the cam in to reduce the high-frequency shaking.
Also check that you are recoding on highest image quality. - this is an environment when you want the max. bandwidth (least compression) for the image data.
shammah98
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Joined: 02 Aug 2010 00:43
Location: Portland, OR

Re: hd video from the airplane

Post by shammah98 »

Thanks for the quick reply! (and sorry for the dup post)
I will try to turn the OIS off next time. Right now the camera is usually on a RAM mount, attached to the panel. I dont think hand holding the camera will be an option, since Im usually handflying at the same time :-) Someone did mention trying a stack of mousepads and placing the camera on that (as opposed to an actual mount), to try and absorb the vibrations...
I'll see how it goes.
thanks again
E
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Doughie
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Re: hd video from the airplane

Post by Doughie »

yes keep those hands on the yoke !!

planes are a high-vibration environment, especially smaller planes. Let us know how you get on - i would definitely try hard to "de-couple" the camcorders body from the plane fuselage and anything bolted to it, or else you'll instantly just transfer those vibrations to the cam itself. Foam or some similar product may help, or maybe just a wool sweater or something?
shammah98
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Joined: 02 Aug 2010 00:43
Location: Portland, OR

Re: hd video from the airplane

Post by shammah98 »

Just a follow up;
So I turned off the OIS, and sure enough the image quality is MUCH better...that is, until there is a change in engine freq/vibration. then it's as if the camera is unable to refocus, and the image stays blurry until i turn it off and back on. Even with it set on manual focus (infinity) Im not sure why it doesnt stay in focus, since it's set on manual, and I have the oIS off?
E
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Doughie
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Re: hd video from the airplane

Post by Doughie »

If you have focus set to manual it certainly should keep focus regardless. Are you sure its a focus issue and not just the cam being shaken at a very high-frequency that may be introducing a blur that looks like it's out of focus but may in fact just be a tiny vibration?
shammah98
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Re: hd video from the airplane

Post by shammah98 »

well, the reason I assumed it was a focus issue is because when I start filming, it's in focus and clear, engine starts, take off, still clear. I can even change the engine rpms while in flight, stays clear. then lets say I hit a patch of turbulence, or i bump the camera, it now becomes unfocused/unclear, and it never resumes the clarity/refocuses after that event. It still has that HD "sharpness", but it's out of focus. Unlike before (when i was shooting with the OIS on), and the picture was dull/cloudy, sometimes wavy, but still in focus (infinty), if that makes any sense
thanks
E
mhardy06
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Re: hd video from the airplane

Post by mhardy06 »

I recently purchased a Canon Vixia HF M30 for filming my flights. It also has OIS and I am experiencing the exact same wavy vibration effect described in the original post. In slow motion it actually looks like my cockpit is expanding and contracting. I've included a link to a youtube video below that shows the problem. It is very significant at low RPM before landing. I have tried using both of the vibration settings in combination with different frame rates and resolution settings with no luck. I haven't tried turning the stabilization off but I will on the next flight! If it doesn't work I'm considering just using it by hand (it works fine by hand) and purchasing a Contour HD for a fixed mount camera. I can't find any information on the type of stabilization it uses if any but I assume that since it's made for sports it should work well. Does anyone have any experience with Contour HD...or better with Contour HD AND single engine airplanes?

http://www.youtube.com/watch?v=wGdKXkzI3LU
Watch for the 2nd landing at 2:30 to see the vibration at its worst.
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Stephan
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Re: hd video from the airplane

Post by Stephan »

Welcome to the forum!

It looks to me like a combination of stabilization and rolling shutter problems.

CMOS sensors don't capture the whole frame instantaneously (like CCD sensors did), instead they scan the whole image line by line - which means the top-most part of the image was captured at a different moment from the bottom-most part (I may be oversimplifying, but that's the idea). This is what we call 'rolling shutter'.

When you're shooting all common scenes in ordinary situations, this isn't much of a problem. But when there is very fast motion, the whole picture is no longer behaving like a single frame, various parts of it seem to move separately, hence the wavy jell-o effect. This is also visible with the propeller which is no longer straight, but looks bent instead. I remember I once shot sideways from a high-speed train, and likewise all poles along the track were bent sideways.

Indeed try turning off stabilization, this could alleviate the problem a bit as these 2 things work together.

About ContourHD, I took a look at their demo video - the one with mountain bikes. IMHO, for your purposes it looks terrible. Like no stabilization and, although maybe it could be the compression and Web upload, I think I see some wavy jell-o effect (I could be wrong). These things seem best for fast action sports where holding a regular cam isn't practical at all, and Contour just lets you record footage that you wouldn't be able to obtain otherwise (like for sports enthusiasts some footage is better than no footage at all). But I wouldn't expect anything polished. Check this video which was taken from a helicopter: http://contour.com/stories/contourhd-video-5--207

I once shot from a similar airplane as yours with my Sony HC3 (4-yr old cam), and like you said when using it by hand there is no issue. So, if you can get somebody to shoot for you, maybe it's the simplest, most flexible option.
mhardy06
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Joined: 06 Nov 2010 06:48
Location: Pensacola, FL

Re: hd video from the airplane

Post by mhardy06 »

Thank you very much for your advice.

I'm going to try a couple of different things. First, I'm going to take your advice and try my current mounting solution (tripod strapped to the passenger seat) without the stabilization turned on. I also ordered a Panavise 809 windshield mount. Maybe the suction cup will provide a small amount of shock absorption. Also, it seems that the scenery outside the cockpit isn't affected as badly so shooting outside the cockpit with a windshield mounted cam may be the way to go. Your CMOS explanation makes perfect sense and I'm afraid it may be more responsible for the problem than the stabilization. My only solution in the end may be some form of shock absorption or a different camera.

I checked out the helicopter video and that black line seems to be the shadow of the blade being captured in the cockpit. I would think a different frame rate would help with that. That video was handheld so it's hard to say how it would perform with the vibration if mounted. They make a version of the CountourHD just for aviation called the NFlightCam http://nflightcam.com but the only difference seems to be that they added an external audio port. I'm definitely going to do a bit more research before plopping down a few hundred on one.

Unfortunately I don't always have a passenger along with me to shoot so that is not always an option. Also, they don't usually shoot what I want them to and tend to move the camera around too much or start and stop recording too often.

I'll post an update after I fly next. Thanks again for the advice!
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