A/B out for 50i

[Ron Aerts]

In the manual supplement it states that, when using system format 1920/50i, on both A and B SDI outs there is a 1920/50p signal @1,5G.
My monitors are pointing out that it is a 50i signal.
Is this a true 50p signal? or is every frame 'doubled'?
I wonder what p.e. my Nanoflash records: half of the lines? It is not capable of recording 50p but it does record the signal.

[Alister Chapman]

If the camera is set to 50i 1.5G then you need to connect BOTH the A and B connectors to a Dual Link capable recorder to get 50p. If you only connect the A feed you will get a strange looking, corrupt double image. 50p requires either dual link using both the A and B connections (1.5G x 2) or 3G.

[Ron Aerts]

tried again

[Ron Aerts]

that's what I thought but a quick test with my sony monitor points out otherwise:
the output SDI, A and B look the same. Also in horizontal moves... No double lines.
Do I have to look for some special artefacts? I don't see any yet.
The signal is recognized as 50i on all 3 outputs. But i don't always trust this recognition software.

[Chris Medico]

Below is a snip from the Wiki on the SDI interface that might help.

This indicates that when using 1.5g dual link @ 50p a valid 50i (or 60i for NTSC) signal will be present at each of the A and B ports (though with an inverse field/line relationship so they sum back into a full progressive frame when both links are recombined).

If you are in RGB mode on the F3 the 1.5g dual link will not produce a usable signal from only one port (believe me, I've tried and hoped it would) but if you are in 4:2:2 video mode it will work.

You can check out the entire paragraph where this comes from here - Serial digital interface - Wikipedia, the free encyclopedia

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In the case of 1080p60, 59.94, or 50 Hz video over a dual link; each link contains a valid 1080i signal at the same field rate. The first link contains the 1st, 3rd, and 5th lines of odd fields and the 2nd, 4th, 6th, etc. lines of even fields, and the second link contains the even lines on the odd fields, and the odd lines on the even fields. When the two links are combined, the result is a progressive-scan picture at the higher frame rate.

[Alister Chapman]

Good homework Chris.

I would question what is written on Wikipedia a bit. The result appears correct but I'm not sure the description is accurate.

There are no fields in a 60P signal, so to say that the links each contain either odd or even lines taken from the first or second field is incorrect as there are no fields to start with. What I believe it should say is that link A takes the odd lines from the first frame for the upper field and the even lines from the second frame for lower field. While the B link takes the even lines from the first frame for the upper field and the odd lines from the second frame.

The Wikipedia implication of taking only odd lines from a single field is that you would end up with resolution of only half a field vertically. I may be wrong on this, but I am pretty sure I'm correct and the Wiki is wrong.

[Chris Medico]

Take a look at this one. It is a more technical oriented source.

http://www.extron.com/download/files...sdihdmi_ts.pdf

It indicates the ODD lines are on one link and the EVEN lines are on the other. If that is the format you would indeed end up with only half of the vertical information on each link.

[Brian Lai]

Is it possible to record 50 f.p.s shots from the F3 to a Ki Pro Mini? I'm still stuck with recording on S x S cards at this stage.

[Douglas Villalba]

1280x720 50 you can not 1080

[Dave Sperling]

Haven't tried it, but new Gemini 444 firmware apparently will alow for recording 1080p50 and 1080p59.94. Hopefully they'll also complete their DnxHD support for the Gemini soon, though I don't even know if the higher progressive frame rates are part of the DnxHD standards..?

[Dan Keaton]

Dear Friends,

Our Gemini 4:4:4, with our latest firmware 1.1.2, will definitely record 1080p50, and 1080p59.94 from the Sony F3.

It is very tricky and confusing, in the menu system, however.

There is no obvious menu option for 1080p50 or 1080p59.94 in the Sony F3.

First, in the F3 Video Set menu select an appropriate Dual-Link & Gamma Select option.

Then, in the F3 Others menu, select System, then select one ofthe following

HQ 1920/59.94i (note the "i") to obtain 1080p59.94 or
HQ 1920/50i to obtain 1080p50

Then the A&B HD-SDI outputs will give you 1920 x 1080, p, 59.94 (1080p59.94)
or 1920 x 1080, p 50 (1080p50).

If you selected 3G, in the first step, above, then you need to use HD-SDI output port A, plugged into the Gemini 4:4:4 Input A.

The easist thing about this is that the Gemini 4:4:4 will report what it is getting.

You may use two or our 256 GB SSD's for 1080p50, but you will need two of our 512 GB SSD's for 1080p59.94.