Atomos Ninja 2 - Manual (Page 6)

Spinning Disk Drives (HDD)
These are the raw storage medium for Ninja-2. You can use either
traditional “spinning” disks, or the new solid state ones. Choose 2
½”
spinning drives if your Ninja-2 is going to be attached to a tripod or if it
is not going to be subject to excessive vibration. For harsher conditions,
choose a solid state drive.
Which drives should you use?
There are so many drives available, and new models appear all the
time. We are not able to test all drives but here are some guidelines.
Speed and reliability are the main factors. Here are a few things to
bear in mind:
• Disk drive data rates tend to be given in megaBYTES per second, and
codec data rates are normally given in megaBITS per second. It’s very
easy to get confused. But there’s no need to be, because all you have
to do to convert megabits to megabytes is divide by 8. So if you’re
recording at 220 megaBITS per second, that’s going to result in 220/8
megaBYTES per second, which is 27.5 megaBYTES per second.
• To see what works for you, you may want to start working with
relatively fast drives 7200 RPM, and then try slower ones 5400 RPM.
This gives you a frame of reference for comparison. Just remember
that the higher the bitrate of the Apple ProRes
® you’re using, the faster
the drive needs to be.
Atomos regularly test hard drives – please check this link before
purchasing drives:
http://www.atomos.com/discovery-what-drives/
Solid State Drives (SSDs)
These are Flash memory devices that come in the same form-factor as
2 ½” disk drives, and they are fully supported by the Ninja-2. See the
section below about when you should consider using SSDs.
Mechanical Shock and Vibration
Hard disks are precision mechanical devices that need to be handled
carefully. You will be using the same type of drives that are normally used
in notebook computers, and you can use this as a guide to whether you
need to use mechanical drives or Solid State ones for any proposed
projects. If you think a particular usage scenario would be suitable for a
notebook computer, then it will probably be OK for a mechanical drive
inside a Ninja-2. If you think the drive inside your notebook might suffer
damage, then don’t use a mechanical drive.
We can’t give rigid guidelines because there are so many different kinds
of drives, each with different mechanical properties. You may even find
variations between drives of the same type.
What we have found is that mechanical drives are suitable for most
purposes that don’t involve harsh vibration or mechanical shocks. They
will be perfect for tripod-mounting, and also for the majority of hand-held
work. We would advise against hard-mounting them on moving vehicles
(but they would probably be OK if cushioned against the body of the
camera operator) and we would not advise using mechanical disks if
there is a likelihood that they might be dropped onto a hard surface.
Here are some things that you should bear in mind when using
spinning disks:
• Even though spinning drives can withstand substantial shocks when
they are not in use, they are more vulnerable when running. Harsh
treatment that may not actually damage the drive may interrupt
recordings at a much lower level of severity. We recommend that you
experiment with your drives by testing them in the conditions that you
normally work in.
• Spinning drives have a gyroscopic effect that you will feel faintly if you
rotate the Ninja-2 up or down or from side to side. They are particularly
sensitive to this type of motion. If you do this too quickly while the drive
is spinning, you may get a small gap in your recording.
• Be very gentle when changing batteries if you are recording. Practise
this manoeuvre so that you are able to do it smoothly. It is always
better to do this in-between takes.
• Do not bang or jolt the Ninja-2 while recording. Gentle and cushioned
movement may be OK.
• You will find noticeable differences in the ability of drives to withstand
shock and to continue recording during vibration and movement. As
we receive reports of drive durability and reliability, we will post them
on
www.atomos.com
• Your Ninja-2 is able to detect when the drive is under stress and it will
recover from any break in a recording by waiting until the drive is ready
to continue, and then resuming from that point. If frames have been
dropped because of shock or vibration, a
“Skippy” Kangaroo symbol
will appear on the home screen on the Ninja-2, just above the disk
capacity indicator. This means that you will not normally have to restart
the Ninja-2, even if a recording has been interrupted by mechanical
disruption to the disk drive. (see Recording and Monitoring: Atomos
Anti-shock Technology for more information)
Taking into account most usage scenarios, we think that mechanical
disks will be suitable in the majority of cases. Spinning disks are most
sensitive when they are rotating. It is obviously best to avoid dropping
them but many disks now have a “drop detector” that will lock the most
fragile mechanical parts in place and protect them from surprisingly hard
knocks. We recommend that if you want to experiment with this, you do
so with a drive that doesn’t contain the day’s shoot!
Backing up and archiving
Remember that no storage medium, including tape, optical disks,
spinning disks and flash memory, is completely immune from failure.
You should bear this in mind when deciding how to manage
your recorded content. At the very least, you should consider the
consequences for you and your business if your storage medium were
to suffer from a sudden failure, and you should back up your content
accordingly. Hard drives that you can use for archiving are becoming
increasingly affordable. You may find that it is completely feasible for
your to keep your master Ninja-2 disks on a shelf (just like tapes!), and,
as a backup, store copies on large hard drives, RAID arrays or Network
Attached Storage (NAS).
2. What you also need
Atomos Ninja-2 – User Manual Edition 3: May 2013 4