FS100 Transcoding: using 5DtoRGB preserves higher dynamic range?

I've been taking in a mix of Canon DSLR and FS100 footage recently for a feature doc.

The program 5DtoRGB by Rarevision has been amazing for transcoding my Canon 5D and 60D footage. For my Fs100 footage I've been planning on using FCP7's L&T.

Yesterday, out of curiosity, I brought an FS100 .mts file into 5DtoRGB and made a ProRes 422 (the same as what FCP7 will create). The results were a 11x slower transcoding, but a surprisingly higher dynamic range. I was actually pretty startled to see the difference, which I noticed mostly in the highlights.

Does FCP7 sacrifice these details in the highlights for speed of transcoding (maybe a dumb question)? As far as gamma goes I thought this was usually the case – people are more discerning to details in shadows and so these are given priority during compression.

I'm now pondering if this is a worthwhile time investment. I'm also wondering why I haven't been able to find much online about transcoding options for the FS100. Are there other ways that would more economical?

Alex

Here is a link to a side by side zoom: http://img820.imageshack.us/img820/2627/fs100sidexside.png

Here are links to the original frames (sample above is taken of the knot in the tree and car wheel) –

5DtoRGB: http://img140.imageshack.us/img140/2035/5dtorgb422.png

FCP7 L&T: http://img221.imageshack.us/img221/2826/fcp7logtrsfr422.png

Looking at the two files on FCPX scopes, it looks like the white are getting clipped.
And the black are lifted too.

Something off with the colour space conversion perhaps. Can you simply rewrap the original, then look at the scopes. Then try using compressor to convert to ProRes.

EX1
MBP
FCPX
Short fingernails