BBC (UK) View on Z1 and HDV

[Jonathan Lee]

Hello,
Thought you might be interested in the BBC's view of the Z1 for broadcast use. Long , but interesting.

HDV and the Sony HVR-Z1E - an introduction
This year is set to be a momentous one for small DV cameras. For the
first time we should be able to
shoot broadcast quality "true" widescreen pictures on a new range of
small DV cameras. We will no
longer have to aspect ratio convert (ARC) DV material for widescreen
delivery, which will have a
significant impact on picture quality.
As well as recording DV and DVCam, these cameras are capable of
shooting true high definition
(HDV). At present however the HDV format is not compatible with most
popular editing systems like
Avid. The potential quality improvement to be gained from shooting in
HDV mode is largely cancelled
out by having to down-convert all material to standard definition (SD)
prior to editing. Until Avid can
accept HDV material directly, (anticipated to be some time in the
summer), we expect these cameras
to be used primarily to shoot standard definition in DV/DVCam mode, as
alternatives to the current
workhorse DV cameras like the PD170 and DSR570 (or PD150 and DSR500).
The Sony HVR-Z1E (everyone's calling it the "Z1") is the first of these
'professional' HDV cameras,
due for launch in February 2005. Interest has been high, and this is an
introduction to its potential
uses, attributes and drawbacks. All guidance herein is based on our
evaluation of the Z1 and the
consumer version the FX1, which was launched before Christmas.
DVSolutions does not recommend
the FX1 for production use as it requires modification for XLR audio
inputs and lacks other features
available on the Z1.
Z1 picture quality comparison tests
We've compared material shot on the Z1 in DV/DVCam mode with material
shot in HDV
mode then down-converted to DV/DVCam. We've also compared Z1 DV/DVCam
material
with material shot on a PD170 and ARCed.
Shooting in DV/DVCam mode. Using the Z1 in DV/DVCam mode produces
considerably
better quality pictures than offered by the PD170 in most circumstances.
Shooting in HDV mode, with down-conversion to DV/DVCam through the
camera or
Sony HVR-M10E deck (through firewire) does not produce noticeably
better quality pictures
than shooting in DV/DVCam mode.
Shooting in HDV mode, with down-conversion through a Snell & Wilcox
Ukon or Sony
HDW-A500 deck: The better quality offered by HDV is realised by
down-converting with one
of these more expensive post-production down-converters.
Page 2 10/02/2005
Using the Z1 in DV or DVCam modes
We anticipate this will be the primary use for the Z1. Of course
recording in DV/DVCam mode means
that no further investment or upgrade of existing DV kit is needed -
the cameras simply replace your
existing DV cameras. Our test results show that the improved lens,
image sensor and its 16:9
capability mean better quality pictures than the PD170 and PD150 in
most circumstances. The 16:9
capability should also make it a viable 'small camera' alternative to
the DSR570 in some
circumstances.

For PD170 users - pros and cons:

Improved picture quality due to new image sensor and better lens. The
Z1 shoots true 16:9
pictures - this means an end to the need for high quality aspect ratio
conversion ('arcing'), or
use of the alternative poor quality in-camera widescreen setting.
Size and weight slightly greater than the PD170, but the camera is
better balanced and...
Angle of view is wider than the PD170 - so no need for a wide angle
adaptor and extra
weight on the front of the Z1, and...
LCD screen nearer the front of the camera - makes operation less tiring
as the camera can
be held closer to the body alleviating manual handling issues.
Assignable buttons for personal preferred camera settings/operations
which should
mean less need to access the camera's menu systems.
Audio operation good - separate built in limiters for each channel, and
easy manual
adjustment of levels. Full auto also available.
If you're shooting a lot in low light, then the Z1 may not be ideal as
it doesn't perform as
well as the PD170 in poor light.
Battery life slightly shorter - about 4 hours not 5.
A shallow depth of field is still difficult to achieve due to the
camera's small image sensor
size, as with the PD170.
More expensive than the PD170 - Rates will vary nationally, but as a
guide, the Z1 is nearly
50% more expensive than the PD170. DVSolutions will hire out a Z1 kit
with sound and tripod
for £65/day, compared to £45/day for a PD170 kit.

For DSR570 users - pros and cons:

True 16:9 widescreen - like the DSR570.
Considerably smaller & lighter than the DSR570 - fewer manual handling
issues.
Battery life is longer - about 4 hours instead of 2.
Considerably cheaper than the DSR570. Z1 kit from DVSolutions £65/day,
compared to £85
for the 500/570.
Low light performance is not as good as the DSR570.
A shallow depth of field is difficult to achieve due to the camera's
small image sensor,
compared to the DSR570.
Lens construction and focussing system not comparable to the
professional, detachable
lens on the DSR570.
Page 3 10/02/2005
Using the Z1 in HDV mode for standard definition delivery

As revealed by our tests, shooting in HDV mode and down converting for
SD delivery can produce
higher quality pictures, but only if the down-conversion is achieved
with more expensive downconversion
devices. DVSolutions can advise on the use of the Z1 in HDV mode, which
must be
carefully considered for a number of reasons:
Higher post-production costs - To edit in standard definition, all HDV
material will need to
be down-converted before editing - meaning additional costs and
processes. For high-end
productions good quality results can be achieved by using a Sony
HDW-A500 high definition
deck or Ukon down converter - both of which need correct set-up.
Availability and cost of
these high-end down conversion tools will vary, and it's not safe to
assume that they will be
widely available in your area - you'll need to check. The camera or a
Sony HVR-M10E HDV
deck can also be used to down-convert, and will output DV/DVCam
standard definition over
firewire. As our tests have shown, using these more economical
down-conversion tools
produces no discernible quality improvements over shooting in DV/DVCam
mode, but it's the
most cost-effective way of down-converting material inadvertently shot
in HD mode.
DVSolutions will publish down conversion guidelines.
Higher compression - In order to record the increased picture
information when shooting in
HDV mode, HDV has to be compressed to a greater extent than equivalent
DV. The effect of
this higher level of compression is unclear at this early stage, and
further tests will follow to
assess any impact on picture quality.
Higher logging costs - Viewing and logging HDV rushes will require an
HDV deck (or
camera).
Drop out in HDV mode - Rather than the distinctive pixellated picture
break-up suffered with
DV and DVCam (audio is often preserved), drop out in HDV mode will
probably mean total
loss of picture and sound, and will last for up to half a second - 50%
longer than most
DV/DVCam dropouts.
Higher stock costs - New HDV stock is available, which is intended to
minimise drop-out, but
HDV can also be recorded onto mini-DV and DVCam stock. The HDV stock
will be at least
100% more expensive than normal mini-DV stock initially, and as yet
it's unclear how much
more robust it will be.
...for high definition delivery
Current BBC Worldwide delivery guidelines state that
"For HD delivery, the use of Standard Definition broadcast and
non-broadcast video formats, and
certain non-broadcast HD domestic formats is not permissible."
So any proposed use of HDV material for HD delivery must be referred to
the High Definition support
group.
These guidelines will probably change now the Z1 is available, so refer
to the BBC Worldwide
delivery guidelines for updates.

[James Darren]

good info & thanks for sharing Jonathan....

One interesting point they made is "the FX1 is not recommended" due to not having XLR audio unless you adapt it.

When you use a beachtek adaptor or similar does the FX1 give you just as good audio as the Z1?

[Gareth Watkins]

Hi

I'm quite happy with my FX1 and adapter.. i guess side by side tests would be needed to see if there is a noticeable difference..

Robin .. who posts on here also seems pretty pleased with his FX and Beachtek...

For me that is really the only important difference with the Z1 and i can't justify the large price difference..

cheers

Gareth

[Sean M Lee]

Isn't autogain always on with the FX/1? not so with the Z1

[Carlos E. Martinez]

Jonathan,


Can you tell me which is the original URL for that BBC article?

Thanks!



Carlos

[Jonathan Lee]

Carlos,
Unfortunately it is an internal article for BBC employees, only available on the BBC's intranet site called Gateway, which is not accessible externally. I got it from a colleague with access.

Jonathan

[Colvin Eccleston]

I can't say I was very impressed with this report, if it is supposed to be the result of intensive testing. There is too much conjecture and indecisiveness for my liking. If they can't come down firmly in favour or against it, they have not brought anything to the table apart from maybe and perhaps.

[Richard Entwistle]

Colvin,

I thought the report was quite good! Typical advisory style, but lots of guidance given for anyone considering the Z1 for DVCAM. Answered my queries Ok. The later reports of some BBC crews changing their old PD150's for Z1 DVCAM use tells us a great deal too.

Jonathan... any updates from your source? I am wanting DV widescreen and was pleased to see the BBC calling the PD150 in-camera WS 'poor quality'. Earlier BBC guidelines suggested it was 'just acceptable'. Technology moves on and so does the quality bar. I was hoping to use my PD150 but that is a no-no for sure. Now it looks like a Z1 (or FX1) or XL2.

Richard
Hong Kong

[Steven White]

Isn't autogain always on with the FX/1? not so with the Z1

I own an FX1 and it is trivial to set the gain to fully manual.

-Steve

[Steven Gotz]

You can always use a picture profile that does not allow the gain to kick in, or you can limit it in steps.

[George Griswold]

Confirms my tests that the down-conversion is not the way to go.... shoot in SD until your NLE can support HDV. I did not share these results because my tests varied widely depending on the subject matter.

George

[Steven Gotz]

I completely disagree with George. I shoot HDV, and if necessary, downconvert. But shooting SD on the FX1/Z1 is just a waste of time for me. Even if I know I will downconvert, I still want to have the HDV for the future. The BBC folks are a couple of months behind the times. And probably because the thread was started back then.

[Steven White]

Confirms my tests that the down-conversion is not the way to go.... shoot in SD until your NLE can support HDV

The way I read it implied that there was higher quality to be had by shooting HDV and downconverting to SD - but that the in-camera conversion does not do as good a job as is possible with more advanced systems. i.e., the best results come from shooting HDV and doing careful down-sampling in "software" (or in their case, better hardware).

All of my tests downsampling 1080i HDV to 480i or 480p60 (uncompressed, using After Effects 6.0 Std) have resulted in absolutely beautiful images - and any macro-blocking artifacts in the original source are on the scale of DV compression artifacts or smaller in SD resolution, with increased sharpness (not-meaning "sharpening artifacts" but rather, higher effective resolution) and colour information. My test subject was a hyperactive kitten.

[George Griswold]

Steven Gotz, let me try to clarify: what I was saying is that I thought the internal down-conversion does not look good to me.
There are external ways to do a conversion as mentioned in the BBC article and they can look good. I not sure what the "behind the times" has to do with the quality of the internal down-conversion--- it is what it is and I don't care for it. Individual preferences vary, and if you have a method that you are happy with-- go for it.

Thank you, George

[Chris Jothi]

So what exactly is 'wrong' or lacking with the in-camera down conversion?

Is it a silly 'clutching at straws, no one can tell the difference at the end of the day' issue, or is converting HDV in post to DV using whatever program going to be immeasurably better images?

Just want to know if it's worth the hassle...