Some of the more commonly asked questions we get about the Sony NEX-FS100 revolve around the HDMI output. Obviously this is a topic many of you are curious about, because just this week we received a message from Juan Martinez, senior product manager at Sony. He wrote a brief (but informative) explanation on the topic that I thought I’d share with everyone. Below is an excerpt from his e-mail:
Signal output: RGB or 4:2:2?
The HDMI 1.4 port used on the FS100 outputs uncompressed 8-bit 4:2:2 or 8-bit RGB signals. Auto negotiation (EDID) takes place when an external recorder and FS100 are initially connected via HDMI and cable. During the EDID exchange, the FS100 and external recorder negotiate the highest quality signal common to the FS100 and recorder. From then on, the FS100 will output the negotiated signal. There is no menu in the camera to force a particular mode.
24P via HDMI
Hereto date; no HDMI hardware supports native 24p signals. The HDMI specification does not currently support native 24p. Instead, the HDMI specification instructs that pull-down1 must be added to 24p signals. Even though the FS100 internally records native 24p, it simultaneously outputs a 60i signal with pull-down via HDMI. As a solution, Sony developed an original method to insert timecode and pull-down markers on the HDMI signal. Timecode allows external recorders to start/ stop and record camera generated time-code. The pull-down marker facilitates externally recording native 24p signals by removing pull-down during transcode.
Early on, Sony approached all major recorder manufactures to implement time-code and pull-down removal. Some recorders already record native 24p from the FS100’s HDMI.
Note1: The pull-down process adds (repeats) fields in order to increase the frame rate from the 24fps to 30fps (60i). The original 24p payload remains unchanged.
None of the recorders we’ve tested have implemented timecode via HDMI as of this writing, but we’re confident that firmware updates will add this feature shortly. The Convergent Design nanoFlash remains one of the few recorders available now that is capable of removing the 3:2 pulldown “on the fly,” so you will not need to do so in post. If you’re using a recorder that does not remove pull down as you record, Andy’s helpful article illustrates how simple the process can be.