如何更好地运twixtor制作慢速镜头，让7D达到1000fps！

之前有一个帖子让7D“拍出”1000fps视频！说的就是使用twixtor这个软件。

[flash]http://player.youku.com/player.php/sid/XMjA2NTY4NDIw/v.swf[/flash]

这里有一些Philip Bloom使用twixtor制作时对拍摄时的建议和后期方面的案例与大家一起分享下。相信观察以上的视频也不难发现。

拍摄工作流程：

1. 建议使用快速快门拍摄：1/2000 - 1/4000s。 [你的照明需要特别充足]
2. 选择一个简单的、纯色的背景拍摄，如天空、墙壁等等。
3. 拍摄行动的最高点。大自然的规律，上升必须落下来。在一个运动的弧/轨迹的顶点对Twixtor工作来说最好，因为在那个点事物一般移动最慢，多更有关帧可以让Twixtor处理。
4. 当你很靠近被摄物体拍摄时，可以人为降低运动速度，比如让被摄物体移动的更慢制造假慢动作来达到慢速效果。（ When you shoot really close/tight, slow the action down manually ie–move slower and fake slow motion [all the tight sequences in ‘Gravity’was done this way and then slowed down a little more with the tools].）拍摄动作时与摄像机隔开一段距离，更容易用Twixtor做出好效果。因为事实上，整个动作有许多个帧。就比如，向上和向下移动你的手臂，在距离镜头前50厘米的地方，摄像机会捕获这个动作，也许就1-3帧。然而，如果你远离相机比如10-15米远，你会捕捉到整个动作，也许有7-10帧。更多的帧就更容易用Twixtor处理。
5. 在50或60fps的拍摄。拍摄高速，代价是你必须放弃分辨率。
6. 你尽可能多地拍摄 - 尝试从不同的角度拍摄动作 - 如果不对就补拍，如果设置不恰当。多拍！ 

后期工作流程：
1. 在After Effects中使用Twixtor - 由于某种原因Twixtor在After Effects使用效果最佳，至少对Philip Bloom来说是。大概是因为AE可以更有效地操纵时间。
以下是一个典型方案。因为涉及软件具体操作为了避免翻译失误还是引用原文吧……

- Move the whole piece over to After Effects via an XML script called Popcorn Island FCPtoAE. You need to export an XML from FCP by going to File > Export > XML [ for FORMAT click Apple XML Interchange Format, Version 5]
- Open AE and go to scripts – look for FCPtoAE and then pull up the exported XML
- Now click on the clip you want to use Twixtor on:  from the MENU go to LAYER > TIME > ENABLE TIME REMAPPING. This allows you to extend a clip our for longer – because when you start slowing stuff down, the clip needs to become longer, which you can now easily do by enabling time remapping – just pull out the edges using the drag function on the clip

2. Check that your Twixtor settings match your footage ie – Make sure your frame rate is correct when you set up Twixtor’s settings. If its not correct then Twixtor will stutter across your footage
- I typically shoot and edit in 23.976fps because I like the film aesthetic.
- I generally find that manipulating the image to a slower speed – say anything between 2-5% yields better results than trying to get something workable at 30%. I don’t know why that is, but I reckon it has something to do with the fact that with many more frames created it uses those created frames to reference from in order to create more ‘interpolated/guessed’ frames.
3. Consider using an aspect matte to hide warping. I often use an aspect ratio of 2.4:1 in my work as a lot of my warping happens at the edges of my shots, thus a matte will hide the really bad sections. One instance of this was a shot in the short of mine called [Fo’tis’ma], where my good friend Franzwa is taking off from a ledge [Its the tight - slightly angled down shot at 34s]. The warping on his hand was REALLY bad – especially because the shot was rather tight and he was coming down at such a pace. It was because of that shot not working at 16:9 that I decided to make the whole piece 2.4:1 [IMAGE 1 & 2]
4. Avoid warping by editing well. Many times Twixtor works for only a few frames – if that’s the case I’ll only use it for a few frames and will cut to the next image – to avoid things looking crappy [obviously this must be done tastefully]. Don’t hang on too long on a shot that was good to start with but warped into mush at the end – EDIT WELL.

来源：http://philipbloom.net/2011/09/13/twixtor/