This is a comparison between a frame from the original comp (top), the same frame from the new comp without the Motion Blur plugin (middle) and the same frame from the new comp once Motion Blur was activated (bottom).

But there are a few bonus uses as well. In addition to adding motion blur, it can also remove motion blur. The effects are subtle, but it can compensate for footage that has a little too much blur on moving objects. Another feature is that you can use the motion from one layer to blur another layer, resulting in some cool transitions and effects. The last bonus is that you can use Motion Blur in place of After Effects' Frame Blending option to interpolate frames of a time stretched clip, often with superior results. There are some great video examples of these other features at http://www.revisionfx.com; I recommend checking them out.

ReelSmart Motion Blur: Limitations
While this plugin is as close to a magic bullet as I've seen, there are some quirks that need to be worked around and planned for in your composites. For one, Motion Blur can have some trouble with motion that extends outside of the frame (see below). This effect is not as noticeable at full speed but is a definite limitation. Also, if your sequence contains only a few frames or extremely rapid motion, the effects of Motion Blur can be erratic, even downright freaky. You may want to account for motion blur in some other fashion if your footage falls into either of those categories.

Motion Blur sometimes
has trouble with motion
that goes outside of the frame.

How ReelSmart FieldsKit and Motion Blur work together
Quite well, actually. To test them as a team, I recreated a shot I made for a commercial about a year ago. In the shot, the background plate is a clip of live action peanuts falling from the sky to make a large pile of peanuts, while a single CGI peanut falls in front of the pile, gets up, then hops out of the frame. Previously, I had to create a clean plate of the live action peanuts, export out a Targa sequence to use as a background in LightWave, render the peanut animation and shadow with alpha channels as separate sequences against the plate with motion blur (so when they were composited the blur would be convincing against the plate instead of a messy black smudge), import the rendered CGI sequences into After Effects, then composite the shot. The problem was when there was a change to be made to the timing of the plate, I had to re-render the CGI sequences to accommodate the changes. Plus, rendering with motion blur out of LightWave added a lot of time. What a pain!

So I tried the compositing the shot again, this time using the FieldsKit and MotionBlur plugins. I brought in the live action peanut shot and interpreted it using FieldsKit's motion masking options, fiddling with the interpolation settings until I had a cleaner plate than before. So far, so good. Then I rendered the CGI peanut and shadow separately without motion blur turned on, which saved quite a bit of rendering time. Getting better. Next, I time compressed the live footage to be one second shorter than the original source, but instead of using After Effects' frame blending, I opted for the Motion Blur plugin to smooth the frames. The results were subtle, but slightly better than frame blending. I then composited the CGI peanut and shadow over the live footage, then nested that comp in another comp, at which point I added the Motion Blur plugin to the entire comp. The result: the finished clip looked almost identical to the original, with the background being a lot cleaner and a with a little smoother motion. The main difference is that I could change any of the elements without having to re-render the CGI peanut elements. Once I crunched a few numbers, I found that I could have saved between 8 and 10 hours putting this particular comp together had I used the ReelSmart plugins originally. Nothing to sneeze at!

The bottom line
ReelSmart FieldsKit and Motion Blur work tremendously well either on their own or as a team. They both live up to and surpass expectations, so we're giving each a Strong Buy recommendation.