Originally Posted by Tugela
HDMI output is pre-compression, so the codec the camera uses to record on it's internal media is irrelevant. In any case, you don't have an RX10 so you do not have the ability to comment on live output. You can't use some other camera to make conclusions about the RX10 (which is what you appear to be doing).
If you record output from playback, then, yes, that would be the same as the recorded footage.
Older cameras used 4:2:0 for their live view output, but that is not necessarily true for newer cameras. The Canon G30/XA20/XA25 output 4:2:2 for example.
Other than the 4:2:0 v 4:2:2 argument (and bit depth), the main advantage for using a recorder is to have footage that does not have (as many) compression artifacts in it, because at some point you are probably going to have to re-encode. You might not see a big difference when you view the Ninja footage against the internal recorded footage, but when you re-encode that is going to have an effect.
The GW77 and the RX10 use the exact same internal codec (AVCHD) so comparing Pro Res to the internal to compare codecs on the GW77 is relevant for what you would get from the RX10, though as you say not perfect. Using a Ninja2 on the RX10 or the GW77 would give similar results unless the RX10 actually did output something other than 8-bit 4:2:0.
Here is the slashcam.de resolution test of the GW77 (55):
Very similar to the RX100 (the RX100 is slightly better). The GW77 and RX100 (same codec) are comparable for this purpose.
I also posted for comparison graded
Pro Res and graded AVCHD from the camera (thus both re-encoded) to check your second argument as well (because I knew this argument when I did it). Theoretically, on compression artifacts, you are correct. But there is no difference anyone can see. And, of course, you cannot do much with color given you still have 8-bit 4:2:0 from either camera (as far as we know).
It is funny that people who do not own or use the Ninja want to argue for it; while I have it, tried it, and find it of little value. I am all ears to be convinced it is worth using. Some even attached it to a BMPCC, where there is an advantage in being able to use larger media (SSD's as opposed to SD's) and use a more informative lcd, but of course it's useless for RAW.
Finally one more thing, which makes all of this really academic: the Ninja 2 cannot record 108060p
. Period. It records 108060i. Cuts temporal resolution in half compared to the 108060p internal. Any takers? [yes, it does 24p].