Speedgrade isn't designed to go pre-edit, so right now there's no dynamic link with the other CS6 apps. It's intended to sit post-edit in a classical film studio workflow, with Sg ingesting only the final edited frames and exporting your production masters.
- If you "send" a Premiere Pro sequence to Sg you will render out a single DPX image sequence (including effects and transitions, and without any references to edit markers or original filenames) and so importing that back into Pr would flatten your entire timeline to a single clip. Any changes to the Pr timeline and you'd have to do it all over again.
- You can export an EDL from Pr and use that in Sg to read the native footage (provided it's compatible*), but grading is not stored into the original files so it won't re-appear in your Pr timeline unless you manually re-import.
If you want to use Sg pre-edit, the options are:
- Grade all your footage before ever touching Pr, export everything to lossless video or image sequences and work with those, forgetting about the original files completely (you'll need a bunch of disk space and hopefully a MOS shooting pattern, as your audio will be split out).
- Grade a sample of every clip you're using, then save a Look for each one. Export the Looks as 3D LUT files (.cube) and use a plugin to apply them to your clips. Right now there's no official plugin for Premiere (Magic Bullet LUT Buddy isn't certified past CS5) but After Effects can apply both the .cube and the .look files via the "Apply Color LUT" effect. Note that some changes in Sg are not included in the Look, such as the choice of color space and tone curve, so what you see in Sg may not be what you get back in Pr.
I'm not downplaying the abilities of Sg, but it's a colorist's tool and doesn't sit very well in the CS6 unified concept of "one person can make a movie". It helps to think of it in terms of the union system in Hollywood - an editor never grades and a colorist never edits, so their tools look completely different, work completely different, and the electronic conversation only goes in one direction.
*Sg was designed with digital cinema in mind so it doesn't work with interlaced footage, plus it generally assumes you're feeding it log so be careful when picking defaults. It's one occasion where something like the Cinestyle fake-log profile for Canon DSLRs comes in handy.
