Nikon D800 with video features

[David Heath]

Originally Posted by Jon Fairhurst

Regarding the HDMI item, it was David Heath who wrote that rather than I. That said, HDMI is always uncompressed. HDMI receivers aren't required to have MPEG-2, h.264 or any other video decoder.

I think what David was referring to is that even though HDMI is uncompressed 4:2:2 at 8 or 10 bits, that doesn't mean that the source signal was ever that good to begin with.(

Yes, just so. You may record internally (and compressed), then replay out via the HDMI. The HDMI signal will be uncompressed, 422 etc - but all the compression artifacts are still there. Same with any imperfections in the front end when a live signal is output. All that saying "uncompressed HDMI, 8 bit, 422" tells you is what it can be connected to. It's completely wrong to infer anything about quality either way from it. Could be fantastic, could be awful.

As analogy think back to film. You may have two cameras, one a cheap disposable, the other a top end Canon or Nikon. In each case they advertise "uses 35mm film". What does that tell you? About relative quality - absolutely NOTHING! But it does tell you what size of enlarger will be needed to make prints.

[Josh Dahlberg]

Thanks for adding so much to the discussion David, your writing is lucid and thoughtful as always.

As someone without the same depth of technical/video engineering knowledge, your comments help illuminate what we can expect from the next generation of DSLRs (primarily designed for stills), and the inherent image penalties.

[David Heath]

Thanks Josh. If I can point to any one single thing, it's to try to make clear that good quality video and good quality stills have conflicting demands for a designer - it's very difficult for any manufacturer to reach a decent compromise at reasonable cost and with power/heat etc etc constraints. That's before we even start to consider ergonomic conflicts. It may be more realistic to just accept having two cameras - one for video, one for stills, each optimised for their strengths!

And so often there is a polarisation of opinion - buckets have to be seen as full or empty, whereas in practice they are half full. I've got a Canon 550D for personal use, and there's the conflict. Part of me can't believe that a DSLR can give video of that standard, the other part is only too well aware that it is not up to the standard of a good true modern video camera, either in sheer quality terms or ease of use. On the other hand, it's better than other "real" video cameras from years gone by!

For personal use, there is no way I am going to spend the money on such as a C300, it's not justifiable. But if you're going to be making a drama with any sort of budget at all, the cost difference between it and a DSLR is negligible when spread over the lifetime of the camera. Certainly negligible when compared to other costs of the production - and if it can save on lighting bills, it may actually lead to an overall cost saving. Same if you're a broadcaster and trying to keep your transmission bitrate as low as possible. A totally false economy if you have to pay out for a higher bitrate to compensate for the coding problems caused by a bit of extra aliasing. (Assuming the bandwidth is there - in the UK there is one HD terrestial multiplex to squeeze 5 channels into. Barely makes it even with decent source pictures.)

And if there is one other thing I really wish to get over it's not to fixate on individual specifications. The obvious example here being the uncompressed HDMI output. It's certainly not a bad thing, but it's a big leap of faith to assume that it will automatically make for high quality. And unfortunately marketing people don't normally help, and that doesn't just apply to cameras. Their job is to sell, and if that means talking things up at the expense of accuracy, well..... what do you expect? Not tell lies, but if selective with what they emphasise, and if people misunderstand in their favour........?

[Jon Fairhurst]

The thing about the clean HDMI output isn't that it gives perfect quality; it's that it removes that particular bottleneck. Heck, you can record to a PC with a RAID without compression in a tethered situation.

That really leaves the sensor quality, the number of photosites that can be read, and the signal processing quality as the only questions - for people who are willing to budget a separate recorder.

Keep in mind that a recorder pushes the system price up to about $6k and you lose the smallness and simplicity of internal recording. Another $1.5K and you can have a 1D-X...

[Peter Moretti]

Originally Posted by David Heath

... All that saying "uncompressed HDMI, 8 bit, 422" tells you is what it can be connected to. It's completely wrong to infer anything about quality either way from it. Could be fantastic, could be awful.

...

David, I appreciate your posts, but this one is very misleading.

In fact, "uncompressed HDMI, 8 bit, 422" says a lot for the D800. It tells us that the signal has been has been demosaiced, gamma encoded, white balanced, color balanced, chroma sub-sampled and quantized to 8-bits, Everything that the camera does to the image has been performed on image, except for running it through the compression codec.

[David Heath]

Originally Posted by Jon Fairhurst

The thing about the clean HDMI output isn't that it gives perfect quality; it's that it removes that particular bottleneck.

Yes, please don't think I'm being critical of the uncompressed HDMI output (I did say "It's certainly not a bad thing...."), quite the opposite. If there's a problem, it's that people are inferring that it automatically means a great front end - it may do, it may not - that's the real point I'm trying to get across.

Originally Posted by Peter Moretti

In fact, "uncompressed HDMI, 8 bit, 422" says a lot for the D800. It tells us that the signal has been has been demosaiced, gamma encoded, white balanced, color balanced, chroma sub-sampled and quantized to 8-bits,

Well, yes, but doesn't the internal codec recording also tell us the same thing? Can't that be taken as read? My comment was really about relative quality, and a big factor there is HOW the demosaicing is done, not that it's done at all. If a simple read out has to be done, the dimensions of the C300 chip are optimum - larger dimensions must lead to compromises.

To my mind, the big advantage of using the D800 (or any other DSLR) for video is going to be cost, if you're going to be comparing it with the C300 (which seems to be the new large sensor yardstick). This is how I see my 550D - far from perfect, but it gives me pretty good video capability in a still camera that I would have anyway. Once you start to factor in the cost of external recorders, devices to improve ergonomics etc that advantage starts to get eroded. (The internal codec of the C300 is fully broadcast compliant.) A few thousand dollars may be highly significant if you're a student on a shoestring - insignificant for even a modest broadcast budget. Let's not forget the camera cost will get spread over many productions.

[Peter Moretti]

I do certainly agree that clean HDMI out of a DSLR can be a "be careful what you ask for" feature. That signal has to be recorded, like you've pointed out.

And no way is an external recorder going to work as smoothly as built-in recording. The best external recorder out there that is made for the somewhat budget conscious is the nanoFlash. It's excellent, but not cheap. And as good as it is, it's not as straight forward as recording internally.

[Jacques Mersereau]

<<<And no way is an external recorder going to work as smoothly as built-in recording.>>>

Right. That is next price point barrier to cross. An inexpensive camera, like a D800, that features SSD recording and can record either uncompressed or something like ProRes HQ or RED RAW.
This seems like it should be do-able.

[Jerry Manco]

Originally Posted by Peter Moretti

I do certainly agree that clean HDMI out of a DSLR can be a "be careful what you ask for" feature. That signal has to be recorded, like you've pointed out.

And no way is an external recorder going to work as smoothly as built-in recording. The best external recorder out there that is made for the somewhat budget conscious is the nanoFlash. It's excellent, but not cheap. And as good as it is, it's not as straight forward as recording internally.

Have you heard of the Atomos- Ninja external recorder, they are about 1,000. Are they any good.

[Jacques Mersereau]

I have heard of the Ninja. The price seems too low for what is truly required - a robust recorder with many more features than one might at first think needed.

I've been looking at both the AJA Ki Pro Mini and the Convergent Designs Nano.
Both of these companies have good reputations and are making continuous improvements.

As always, YMMV.

[David Heath]

And an external recorder can only record as good as it's given. It can be an improvement, no doubt, but if the front end of the camera isn't very good, it can't make that any better.

[Sareesh Sudhakaran]

Maybe one day we'll have a camera with a non-proprietary SSD slot for uncompressed DPX image sequences. I won't even mind a DIRAC codec in an MKV container.

[Arne Pursell]

As someone primarily insterested in documenting climbing/skiing/trekking, the D800 sounds fantastic on paper, apart from perhaps the low-light. Bear in mind I haven't upgraded from my HV20 and HV30 yet (I was hanging on for clean HDMI out). Aliasing and moiree are less of an issue for me, as opposed to greater MP and decent video, with the chance of recording to a ninja if I ever get out of 'amateur' ghetto.

However, I still am considering 5dii, as well as the APS-C cameras (although having shot in a previously life on 645 film, I MUCH prefer larger sensors and less distorted perspective - i.e. full-frame).

Here's the rub - given it's unlikely I'll be using a ninja much (the others are out of my price range), I would have thought the Canons with magic lantern have a big advantage over the 800d (bitrate, all the rest of it).

Any thoughts as to how the in-camera codecs stack up? Or is it too early to say? Extremely impressed with the NEX-5n footage I've seen too. Need the photo-side that DSLR's offer (otherwise I'd jump at the FS100 - although a bit out of my price range).

Agnostic as far as glass goes, have some older Canon FD and radioactive FL lenses that could be adapted to most mounts (love my 58mm 1.2!)..

[Andy Wilkinson]

I just read on another site that a large quantity of Nikon D4 and D800s were stolen from a van in Dublin.

Might delay these new products availability (well legal availability anyway...) for a while in this part of the world.

[Jerry Manco]

Can anyone answer me this, between the Nikon D4 and D800, which one will give you the better video, if at all. The difference, one 16 megapixel and the other 36 and one more light sensitive(D4) than the other. Can one say or predict according to what they offer. Would be much appreciated.