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-   -   External Recorder for Z90? (https://www.dvinfo.net/forum/sony-4k-ultra-hd-handhelds/535142-external-recorder-z90.html)

Bill Ackerman December 27th, 2017 06:25 AM

External Recorder for Z90?
 
I'm going to be buying a field monitor for my Z90 and am wondering about the benefits, if any, of the models that can also record the output from the Z90 HDMI or SDI port. This is my first foray into 4k so I have zero experience with the codecs.

The video I record is for compositing and visual effects within Adobe AE, Cinema 4D, etc. Final delivery for the foreseeable future will continue to be HD, but the higher resolution from 4k should help me with keying, masking, rotoscoping, color matching, etc.

Any guidance would be greatly appreciated on whether external recording from the Z90 is worth looking at and what recorders are recommended. Many thanks!

Mark Watson January 26th, 2018 07:39 AM

Re: External Recorder for Z90?
 
A month later and no replies. I don't do any rotoscoping, and very little masking and green screen. But, I can still give my input on your question.

I just got my Z90 this week and haven't had a chance to put it through its paces yet.

I have two external recorders (BMD Shuttle 2, Odyssey 7Q+) and an external monitor (SmallHD DP6). The Shuttle 2 can record uncompressed, or a couple types of ProRes. What I found out, was recording in uncompressed from a variety of video cameras, including the Canon XF305, had no advantage than what the camera recorded internally. That's because those cameras I was using the recorder with did not output better than what was recorded internally. Some cameras have higher spec output available on their HDMI or other terminals, but for cameras that do not have that feature, an external recorder will not give you a better looking image. Uncompressed video takes up lots of memory space, but in my case, it did not offer anything as far as a more editable video file.

For this type of camera, and I would include the Z90 in this group, an external recorder would be mostly of interest to those who want a backup recording system. Like for special events, like weddings. So if there's a failure with the internal recording, you have a backup copy. Now, the Z90 does have dual recording capabilities already for its internal system, negating the advantage of an external recorder if your main concern is memory card failure.

On my FS7, the output of the raw adapter is of a higher spec (on paper anyway) than what's available with the internal recording options. That is why I got the Odyssey 7Q+. In retrospect, I don't think the hassle of getting the raw files is worth it. But, it is still a very capable monitor, and that's what I mostly use if for now.

Adding an external recorder to a small form-factor camera like the Z90 is also going to make handling more difficult. I don't like shooting handheld with these smaller cameras with my monitor/recorder attached to the them. A bit unwieldy. On a tripod, it's much more manageable. Something to consider, depending on your shooting style.

If you need an external monitor, I'd recommend you narrow down your choices based on what you want in a monitor first, then if one of your finalist also happens to have recording capability, fine, get yourself a recorder. But if the top choice does not include a recording capability, then skip that and just go for the monitor. It will probably be lighter and easier on batteries.

I've looked at the HDMI/SDI port specs listed in the operator's manual for the Z90 and I don't see anything that would lead me to expect any better output on those ports than what gets recorded internally. I'll run some tests eventually just to know for myself, since camera makers don't always provide the full details of what's available on the ports.

Mark

Bill Ackerman January 26th, 2018 10:17 AM

Re: External Recorder for Z90?
 
Thank you, Mark, for the very helpful response. Since my post, I have had a chance to put Z90 internally-recorded footage through many tests and am completely satisfied with it so far. I cannibalized a smallHD DP7-OLED from another rig - a little on the heavy side and overkill for my needs, but the scopes and LUTs have been helpful.

Really happy with the SDI port - main reason I went with the Z90 over NX80. I hate, hate, hate HDMI cables; the number of swear words I invented due to HDMI cable mishaps is a source of both shame and pride.

Mark Rosenzweig January 26th, 2018 12:47 PM

Re: External Recorder for Z90?
 
What you gain from an external recorder is a video file with much less compression. High compression is what is responsible for most of the issues when one heavily grades, or even if not - these include banding (yes, higher compression has a worse effect than going from 10bit to 8bit), macroblocking etc. Clips "falling apart" results from heavy tweaking of highly-compressed video.

If you do a lot of grading, there is a real advantage. You also get better sampling of color (4:2:0 internal versus 4:2:2 external ), but I have found that difference not to be as important as working with files that are not so heavily compressed. Thus the "specs" of the internal and external video are not the point - the point is that you can record at high bitrates externally and avoid the very heavy compression internally. Almost all videographers complain about the low bitrates.

If you use an external monitor anyway, you might as well get one that records. The output from Sony cameras is clean and uncompressed and 8bit 422. The recorders can record at much higher bitrates than the camera can - ProRes 422 HQ, for example. The video files are also much easier to work with in editors, because of their low compression.

Christopher Young January 27th, 2018 01:04 AM

Re: External Recorder for Z90?
 
1 Attachment(s)
Agree on the compression point of view but for accuracy sake if you are talking SDI HD output on the X70 and the Z90 both of them deliver full 4:2:2 10-bit as in the XAVC internal recording.

The SDI output in HD is not 4:2:0 8-bit. The 4:2:0 8-bit only applies to the internal 4K and AVCHD internal recording. That said UHD is not available via SDI. When shooting UHD the HDMI output is 8-bit 4:2:2.

See NOTES at Atomos. The Z90 is the same with respect to its outputs

https://www.atomos.com/cameras/sony-pxw-x70

Chris Young

Kevin Lau January 27th, 2018 03:27 AM

Re: External Recorder for Z90?
 
Do either of these models now support 2160p output over HDMI or are there restrictions? I own the X70 but have been reluctant to get the QFHD upgrade license as I feel there are still some key limitations even after 3.0+ firmware.

Mark Watson January 27th, 2018 09:59 AM

Re: External Recorder for Z90?
 
The Z90 can output UHD during recording, but you lose the in-camera display. I did a test today with the Odyssey 7Q+ and compared the image quality of the internal UHD XAVC 4:2:0 100 Mbps to the UHD PRORES 4:2:2 HQ 900 Mbps video. No perceivable difference. Did a light grade on them..... no difference.


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