Compositing Hi-Res Stereo Images - Nuke 101: Professional Compositing and Visual Effects - page 359

Now that Proxy Mode is on, what happens is that, much like the Viewer Down-
scaleResolutionyouusedbefore,imagesarereadinandscaleddown,theViewer
scales the images back up, and all pixel-based values are changed to reflect the
smaller resolution.
AsshownbeforewhenusingDownscaleResolution,thereisstillsomeprocessing
done on the full-resolution image. Nuke has to read in the whole image to scale it
down. It does this on the fly, without your needing to do anything else. However,
this stage, too, can be removed.
Instead of using on-the-fly proxies as you are doing now, you can be reading
smaller-resolutionimagesdirectlyfromaspecifiedlocationonthedisk.Thisway
the images are already there and will always be there, and no processing ever
needs to be done to them—resulting in a quicker workflow throughout.
Let's generate some proxy images. These are sometimes called pre-rendered
proxies because they are not rendered on the fly.
10. Create an unattached Write node and connect its input to Read1.
11. Click the little folder button beside the Proxy property ( FIGURE 8.28 ).
Figure 8.28. This time you should use the Proxy property instead of the File
property.
12. Navigate to the BulletBG directory inside the chapter08 directory. Create a new
directory here called third (if it doesn't already exist).
13. Nameyoursequencethesameasthefullresolutionone: bulletBG_left.####.dpx
and press Enter/Return.
Thisisaprettystandardwaytoworkwithpre-renderedproxies—haveadirectory
with the name of the element. Inside it, have a directory for each resolution and
then keep the sequence name the same.