Video Assist - 1080i 50fps?

After much anticipation I now have my awesome little monitor/recorder. When I connect it to my Sony A7s it says 1080i 50 even when I go into the settings and have it output 1080 25p.

I have the same thing with my Sony F3. With that camera I can get it to see 1080psf 23.98 (I'm in NZ so don't use this often). But with every other setting 1080i 50fps comes up on the Blackmagic Video assist screen.

When I bring this footage into Premiere it says it is 25fps but is interlaced, I can conform it to progressive and it doesn't seem to have any interlacing lines but I'm concerned if I give this footage to clients they will freak out that it's interlaced.

Anyone got any ideas on how to output progressive from these cameras? Or is it the recorder? Should I care?

What am I missing here?

It is Sony, and most other camera makers. When HDMI was added to video cameras as an output, then current HDMI standard was only HDV 1080i/720P, as this is what rhe TV set were then, and the HDMI was to output the camera to a TV to view the footage. So in order to get a 1080 signal through the slow HDMI interface, and to conform to the then broadcast standards, which was interlace, Sony and everyone else then added a 2/2 (PAL 25p signal) or a 2/3 (NTSC 24p) pulldown to convert the progressive signal to an interlaced signal that would work with HDMI and the monitors/TV that were then available. External HDMI recorders were not in use or available then, FireWire was used to feed external recording devices.

So your Sony cameras are adding the pulldown and converting the 24/25P signal the camera is recording at to a 50/60i (interlace) signal. For details you can look at Wikepedia for a nice history, explaination.
The short of this is, the Video Assist does not remove the pull down at this time p, so it records,the signal as a 50/60 interlaced signal, which you can confirm back 24/25p on your editing program. The VA will however, convert a 24PsF signal on the SDI input only (not HDMI).

Today, HDMI can transmit the faster resolutions up to 4K, but camera makers are restricting the output on consumer/prosumer cameras to keep the market for,their more expensive "Pro" cameras from being undermined. Also in EU, a camera with continuous broadcast standard outputs or can record for more than 29 min. are considered "Pro" cameras, and taxed (VAT) at a higher rate. This is why most DSLR cameras only record for less than 30 min. and only have a crippled HDMI interface.
Cheers

And here I thought the approximate 29 minute length was due to the 4GB file size limit which is reached then when recording that ubiquitous HDV 17Mb/s bitrate common on many cameras years ago.

Maybe we're both right.


Sent from my iPad using Tapatalk

Rick, yes, yes we are. The FAT format used by early SD/CF card cameras had a file size limitalso, but this could be overcome by auto recording to multiple files, like the Panny AF100 does. EU regs., also added to the restriction to keep these type of cameras crippled to avoid VAT increases from what I understand.
Cheers

Canon DSLRs up until the most recent ones actually have both, where you hit the 4GB limit at around 12 minutes at 1080p30 45 Mb/s stock, but if you set the bitrate lower with ML or used a smaller frame size, you couldn't go over 29 minutes no matter what. However, proper video cameras generally span clips for a good long while now (like my old Panny AC-130A, same gen tech as the AF100A), and given massively higher bitrates and more expensive cards, the 29:59 limitation doesn't matter so much for digital cinema cameras of this type either way.

Yes, the 29.xx min. limit is what defines a "still camera" with video capability from a true video/Pro production camera and the cooresponding added cost. For Video/Cine production cameras, only the size of your media and your recording got rate limits your recording time.
Cheers

Thanks for the responses. After more research it looks like with the Sony F3 via SDI that the signal is PSF 25p but the BVA sees this as 1080i 50fps.

I researched the hell out of PSF and camera outputs and pulled it into Premiere and it seems that it is PSF 25p but the Blackmagic Video assist just doesn't flag it as such. In Premiere you tell it to interpret the footage as progressive and then all is fine.

This would makes sense that is seeing 1080i, as it's SDI psf which means that instead of a upper and lower interlaced field being sent down the SDI cable they are the same progressive scans. Which also makes sense of the 50fps coming up (which Premiere sees as 25fps).

So now my question is, why does the BVA flag 24PSF but not 25PSF?