Altitude Limit for SR1
 

"You cannot use the camcorder in places where atmospheric pressure is low (above 3000m)."

From Sony's Japanese website.

http://www.sony.jp/products/Consumer.../sr1-info.html

Fortunatly, that's 9900 feet. and commercial airliners pressurize to 8000 feet.

But climbing mountains... that's another story.

Do any other cameras have altitude limits?

All hard drive-based camcorders are limited to less than 10 grand MSL.
All hard drive anything is limited to less than 10grand MSL.

General public doesn't know it, but skydivers sure do. Fastest way I know to kill an iPod is to skydive with it in the mountains where you're typically around 15kMSL or higher.

So do HDDs blow up beyond 3000M?

If it's like that, all hard drives coming in by truck from Salt Lake City to Denver on I-70 would all blow up?

I'll assume you're being facetious.
All HDD manufacturers warn that their products may fail above 10,000 feet above sea level. Read your specifications on most any HDD you own.
What does SLC/Denver have to do with it?
Is that to say your drive will automatically shred if you cross the line? No. I've jumped with several hard drives, I've also spent a lot of time in Telluride where you're at 12k all day. Drives work. But early failure is expected, and it usually comes faster than slower.

http://www.seagate.com/support/disc/...Use&Safety.htm

http://www.westerndigital.com/en/pro...sp?driveid=244

http://www.moosepeterson.com/gear/fortress.html

Read the altitude specs on any of those, or look at your Mac laptop or iPod manual. ALL of them have operational ratings of not higher than 10k. Non-operational rates vary between 15k and 40k.
I've killed one iPod and killed a couple cheaper HDD units in the past. Himalayan climbers have killed laptops and iPods with some degree of regularity.

So what is the real cause for these failures?

Air pressure causing a shift in distance between the reader and the platter.
If I remember right, anything shifting more than 3 microbars of airpressure creates trouble, but I could easily have that value wrong. I'm sure someone will correct me if I am.

Remember....read/write heads "fly" on a film of air, so too little pressure and it crashes into the surface.

Jeez, I think the modern day hard drive needs to be redesigned alltogether.

By the way, this image is irony in all ways:

http://www.sonystyle.ca/html/images/...a7_titlein.jpg

Hmm, somebody out there has to have invented an air-tight hard drive pressurized to sea level that can be taken up into high altitudes. For one thing NASA probably has a need for hard drives that can operate in a vacuum.

If things are still like they were a few years ago, hard drives have a small vent to allow pressure equalization and also contain a small amount of dessicant to keep the incoming air from bringing moisture with it. We're talking rather microscopic quantities of course.

I think there may be more to it than just the thinness of the air - we used to have problems with the ability of the thinner air in Denver to effectively transfer heat from air cooled mainframes and there might be some of this at work here too. As I remember, the cooling capability related to the mass of the air.

Also, be sure to recognize the difference between operational and non-operational limits. You can ship at very low pressure as has been pointed out here.

You'll need sealed and pressurized hard drives for high altitudes. From this link:
"The HDD's spindle system relies on air pressure inside the enclosure to support the heads at their proper flying height while the disk rotates. An HDD requires a certain range of air pressures in order to operate properly. The connection to the external environment and pressure occurs through a small hole in the enclosure (about 0.5 mm in diameter), usually with a carbon filter on the inside (the breather filter, see below). If the air pressure is too low, then there is not enough lift for the flying head, so the head gets too close to the disk, and there is a risk of head crashes and data loss. Specially manufactured sealed and pressurized disks are needed for reliable high-altitude operation, above about 10,000 feet (3,000 m)."
For these reasons, video filming on mount Everest must still rely on miniDV tape.

Wow. That article on Everest/production is flawed from so many angles, it's hard to know where to begin. Sony has not "discontinued miniDV tape," for starters.
Try shooting in this Everest environment. I'm one of the people on that particular journey; looking forward to shooting, and I'll be carrying one HC5 and one SR7 on the jump.

Either way, as I'd written earlier, HDD units cannot be relied upon above 3000M/10K feet MSL.

This is almost correct, but there are couple of oversimplifications.

Saying that the disk relies on air pressure to keep the heads separated from the disk surface is technically incorrect. The separation is achieved by a thin film of air that is dragged along by friction with the spinning disk. If the disk stopped spinning, the head would contact the surface regardless of the pressure in the enclosure. At high altitudes, the effect is still present, but it would be more analogous to using an excessively thin motor oil in your engine and would lead to the same kind of failure

Actually, the head suspension is pre-loaded to force the heads against the disk with a known force. Quite a few years ago there were experiments using a truly sealed enclosure filled with Helium in order to reduce air friction which is the main cause of heat in the disk. At the time they were thinking of this as a way to get rotational speeds higher without bigger motors and excessive heat buildup. And of course the head suspensions would have required appropriate modification to deal with the lower lubricating effect of the Helium. As data densities increased, the size of the disk itself could be reduced and this was enough to make todays rotation speeds feasible.

Small gyroscopes (including those for camera stabilization) do actually use Helium filled enclosures to enable the extremely high RPM used without high heat.

In the "old days" when disk drives were the size of large refrigerators, the sliders had small vents and high pressure air was actually piped to small holes around the read/write head itself. As things got smaller and lighter, this could be dispensed with.

I think that modern tape drives rely on the same phenomenon to provide some degree of lubrication between the head and the tape so I'd expect somewhat higher wear rates at high alitudes for tape as well. I think we spec the same 3k meter operational altitude limits for our tape drives. Might be wrong on this, though so I'll check it with the engineers on Monday and let you know. None of this means that the drives won't work in Cuzco, Peru (11+k feet), it just means that they'll wear more quickly and warranty claims might be denied.

Whether it is correct or not, I'm telling you from several personal experiences that the drives will not work correctly at altitude, if they'll work at all. I'm consistently at unpressurized altitude (18 times over the past 3 days alone) and the drives, whether in a laptop, iPod, or DR60 will either immediately fail, or fail within a very short period of time.
Whether it's air pressure, lubricant, or little green men with an axe to grind, the drives require pressurized enclosures to work in these environments.

Doug,

Sorry - my response wasn't to your post but to the post before it that quoted the Wikipedia article! Yours came in while I was writing mine!

Sorry for any confusion. I certainly agree with you that regular drives are not intended to work at altitude.

On the other hand, neither are tape drives although the failure rate would probably not increase as much as for a disk drive.

I don't think that the Wikipedia article implied that the head gap was maintained by air pressure, it merely states that you need adequate air pressure in the drive enclosure, which is true, since reduced air pressure will cause the head to lose lift and eventual disk damage. This principle is well described by a statement in this article:
"When the disk spins up to operating speed, the high speed causes air to flow under the sliders and lift them off the surface of the disk--the same principle of lift that operates on aircraft wings and enables them to fly... If a drive is used at too high an altitude, the air will become too thin to support the heads at their proper operating height and failure will result; special industrial drives that truly are sealed from the outside are made for these special applications."

"The HDD's spindle system relies on air pressure inside the enclosure to support the heads at their proper flying height while the disk rotates."

Well, it certainly sounds like they said it was the air pressure that supports the heads (while the disk rotates.) In fact it's exactly what they said.

At best it's mis-stated. You could have 10k PSI inside the enclosure and rotate the disk at 1 RPM and the head wouldn't fly any better than if you had 0 PSI, even though you a) had ample air pressure and b) were rotating the disks.

By the way - nice reference, Thanks!

You're absolutely right, that statement is somewhat misleading...

Seagate has new PATA and SATA EE25 drives rated to 16,400ft.

I'm now headed to Lhasa and EBC, so will be taking these along.

EBC is at 17,700, so I'll be waiting until I am down at Xeger before using the computer.

Douglas, would love to hear your experiences when you get back, I'm off on Nov 17th, hopefully with a new Sony XDCAM EX in hand.

I'm about to buy a Sony SR12. We'll be travelling to Alaska and the Canadian Rockies in May and will be doing several helicopter and float plane trips. I've looked up elevations of major places we'll be visiting (Banff, Lake Louise, Jasper, Whistler, Ketchikan, Juneau, Skagway, Anchorage, Fairbanks etc.) and all seem to be well under the 3000m limit for HDD camcorders.

The highest point along the Icefields Parkway between Lake Louise and Banff is Bow Summit at 2,069 metres (6787 feet above sea level) while the elevation at the Village of Lake Louise is 1,534 metres (5,033 feet). The top elevation of the Lake Louise Mountain resort is 2,637 m (8,652 ft).

If we do helicopter flights I don't think it's likely we would fly high enough to go over the 3000m limit. Has anyone used a HDD camcorder in areas like this and had any problems? Would it be better if I recorded to memory stick in higher elevations rather than to the HDD?

Thanks for any advice.

Ken

You shouldn't run into issues regardless, unless you fly over 9400 MSL. But...Supposedly, if you place a card in the mem slot and CHOOSE the MSPD for recording, the HDD head parks. I've been waiting for a test unit from Sony to check this out.
In other words, you should be fine.

It may not be. I was asking this question in another thread; that is, if the hard disk shuts down when you record to card. After listening to their units, people that have SR12's seem to have determined that the disk does NOT spin down when using the card.

Unfortunately, just parking the heads is not good enough, the drive must spin down completely to be safe. Parking just means that the heads are positioned over the landing zone; in modern drives, parking the heads does not mean that the heads are physically pulled away from the platter, although that misconception is rather common. The landing zone is safe for brief head contact during head take-offs and landings, but not if the head begins to rub constantly because of insufficient pressure.

Here's a good description of head parking and landing zones:

http://www.storagereview.com/guide20...ctParking.html

Unfortunately, if the disk truly does not spin down, the safest thing would be to refrain from using the camera at all above 10,000 feet.

I'll definitely be curious if you find out from Sony that these assumptions are incorrect.

I'm going through the same dilemma right now. I would like to get an SR11, but a lot of my usage will be on climbing/skiing/backpacking trips, so I will have to stick to either tape or Flash-only cameras. I wish there was some knowledge of when a CX9 might come out ;-)

Doug it would be great if you could get back to us on that. I know on my SR12 I do hear a very low sound and a very subtle vibration even when recording to a memory card. I don't plan on recording at these elevations anyway, but I've been asked this question by a number of people.

Some have said that even if the platter is spinning the head could still be parked. I don't enough about the mechanics of these things to comment.

P.S. I just read Dave's comments above and I'm confused about one thing. I would think if atmospheric pressure lowers, that would lessen the chance of contact between the head and the platter. I can see increasing atmospheric pressure heightening the chance of contact as additional pressure pushes down on the heads. So I guess I'm confused about this seemingly contradictory correlation. I guess it's my lack of understanding of this process. I guess my degrees in Meteorology aren't helping me here! :)

I think its the density of the air that matters. At high altitudes the air is thinner and just like an aircraft wing the head would need to move faster over the platter to get lift or would need a larger surface area to get the lift. Normal heads are designed to lift at the densities associated with lower altitudes. Increasing pressure increases the density, increase the pressure enough and the gas will turn to a liquid in most cases.

Ron Evans

Ron, that makes perfect sense. I wasn't thinking about it in that manner at all, but I should have been.

There's always a chance I could be wrong about this. I know a fair amount about disk drives having designed chips for disk drives for a number of years, but I'm the first to admit I don't know everything, especially about the mechanical side. What I am pretty sure of is that *conventional* drives (like the type in most computers and laptops) don't have a special mechanism that forcibly lifts heads away from the platter when the heads are parked - they are just floating over the landing zone.

It *may* be possible that there are special drives that can do this, just as there are special pressure-sealed drives that can be used in low pressure environments, but I'd be surprised if these would be used in a consumer level camera.

In addition to this, there are other concerns. For example, we can't easily know that the camera doesn't use the drive for other things, such as storing firmware or device state information - many systems with embedded hard drives do this. Also, the drive may be accessed as part of the normal POST procedure when the camera is powered on or off.

Personally, I wouldn't risk it unless given the go-ahead by a Sony engineer or technical support person. At least in that case, if it bricks your camera, they will probably take responsibility since they told you it was OK.

Hi from Greece. First sorry about my english - american. In 2 days i will fly above the agean sea and i would like to capture some footage. I will fly with an airplane. I don't know exactly the height the airplane fly. Would be any problem to use my GZ-HD3(JVC) with HDD inside the airplane? Or all what you say is to walk by feet on these heights?

I'm curious about the G-force sensors? What happens when the G-force is exceeded? The drive likely doesn't stop spinning. Is the head pulled away from the disk or simply moved to a parking zone?

I wonder of laptop and camera drives might actually pull the head free of the disk because they are at such risk of shock? Especially, when the drive is off.

To keep start-up time to a minimum, the drive may be kept spinning. And, the head pulled away when not writing or reading.

HDD and altitude (Sr12)
 

[This is the response I got from sony after the fourth attempt to get some continuity. All answers previously received were diiferent. sony US wouldn't answer me because I bought my Sr12 in Au.
Hi Geoff,

Below is the best response I can get from Sony.

Thanks, Jeff(this Jeff is a video technician)



a. Is the HDD completely independent of the operation of the MS?? Yes


b. Does the HDD spin while recording video to MS?? I would say No


c. I am travelling to Sth America in March and want know if I can

safely ONLY using MS, record to MS then the back up using portable DVD
burner

at Cuzco (Peru) and La Paz (Bolivia) both place are above 3000M?? Out of
the Operation Manual "Note on using the camcorder at high altitudes - Do
not turn on the camcorder in a low pressure area, where altitude is more
than 3000 meters or 9800 feet. Doing so may damage the hard disk of your
camcorder. This is also when using memory stick because when turning on
camcorder will initialise and activate hard drive.


A suggestion if he's after a non HDD, he could research the HDRTG1E.

Or a CX100, or a CX6/12.

CX100 is very impressive. So is the MC1.