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Shooting for Matchmoving and Motion tracking


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Hallo everybody,

I'd like to talk about shooting tech for Matchmoving and Motion tracking VFX. I mean: when we are sure the footage we're going to shoot will be used in post VFX for needs of Matchmoving and Motion tracking for needs of, should be shoot with 50, 60 or more fps? Should it help tracking and matchmoving even if we have e Lock-off camera and or e very slow camera movs (shortly, without motion blur)? And anyway, using more than 24, 25, 30 fps, (50, 60. 100 and more and more fps) how affect the visibility? I mean, after tracking, could I transform native high value fps in a standard 24, 25 or 30 fps so thatt can I visualize video in a "Normal" way, without any "ralenty" or slow/fast motion effects?

 

Thanks for a reply! :D

 

 

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There is no need to shoot in frame rates above 24p for visual effects. 'Bluescreen' movies are still shot at 24p, unless your Peter Jackson and you are working on The Hobbit. Motion blur is rarely a problem, but you do need to take extra care when filming that you try to avoid REALLY bad motion blue.

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Matchmoving needs lots of tracking points (at least couple of dozens minimum, ideally can be couple of hundreds depending on the shot) so you should be extra careful when shooting these and always consult your vfx supervisor first. Especially when shooting matchmoving shot on green or blue screen where there is no natural tracking points on background and mid range (depth). No specific need for higher framerates normally but blurry tracking can be very challenging... Also try to not shoot a way that the object masks all the tracking points one at a time and thus not having any continuous trackers..much more difficult to solve the track

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Thanks guys, yes, anyway the focus was on Matchmvoing and not about all type of VFX. For slow motion effects, i.e. you need high frame rate. And I ask to me if maybe it a good idea to shoot again in high frame rate when you shot an action scene or a very electric commercial spot or music video-clip, all cases where you have to insert in post moving text, graphic, vfx like explosion, laser blaster, etcetera...

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I do a lot of green-screen type work, and can say that I have never seen a need to shoot in anything other than 24fps and at a 180 degree shutter. Then again, I'm no fan of wild camera pans and such, favoring slower movements - so motion blur has never been a problem. Ultimately if you are planning to do fast camera pans or other sudden camera movement, the first place I would look is to bring the shutter down rather than mess with the frame rate - that is just my opinion though. Trying to key blurred footage is bad enough, trying to track it is a nightmare.

Edited by Landon D. Parks
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I do a lot of green-screen type work, and can say that I have never seen a need to shoot in anything other than 24fps and at a 180 degree shutter. Then again, I'm no fan of wild camera pans and such, favoring slower movements - so motion blur has never been a problem. Ultimately if you are planning to do fast camera pans or other sudden camera movement, the first place I would look is to bring the shutter down rather than mess with the frame rate - that is just my opinion though. Trying to key blurred footage is bad enough, trying to track it is a nightmare.

Hi Landon, I don't like wild camera movs, as well, but even with a lock off Camera, in a battle, fighting or action scene, you have drastic movements of the Characters, or objects (i.e. props, weapons,etc....) in scene. In these cases shooting with a high frame should help to avoid undesirable motion blurs.

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blurry footage CAN be keyed with good results, to a point.... if your compositor is experienced... but combining blurry footage keying AND matchmoving may not be the best idea generally because it complicates the shot as a whole and makes marker using more difficult. for example matchmoving a wildly moving handheld camera on greenscreen :blink:

 

what types of camera moves and scenes you are specifically wanting to shoot and which type of elements need be added to them?

you were talking about lock-off camera matchmove shot, did you mean you have a character which need to be replaced with cgi character in post and you will only track this character without moving the camera at all?

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