Sunday, March 18, 2012

SONY NEX OVERHEATING: Final Test Results

SUMMARY



After numerous tests and re-tests my conclusions are the following:
  • There are ways (some more obtrusive than others) to lower the surface temperature of my NEX.
  • None of these methods individually or taken together modify the following, essential characteristic of the NEX:
    • From cold the camera will heat up, display the thermal warning, and then may or may not make it to the 30 minute mark (at which point the camera reaches its maximum 30 minute segment record time.).
    • If the camera records to the 30 minute mark, then trying to record again immediately will result in thermal shutdown after a few minutes.
    • If in either case, if one allows the camera to cool for 4 to 5 minutes, then the camera may record one or two more additional 30 minute segments (allowing for cool down in between), most often  without any warnings, even though the recorded surface temperature is well above the point where shutdown previously occurred. 

The best strategies for increasing the chances of making it to the initial 30 minute mark are, in order of effectiveness:
  • Use the Sony 32 GB Memory Stick PRO-HG Duo Media 
  • Use the AC adapter instead of the battery.
The following offer only marginally small improvements to cooling and/or record time.
  • Keep the LCD open and use a small, portable fan.
  • Remove the rear label and apply heat sinks and use a fan.
WHAT'S WRONG WITH THIS PICTURE?

Yes it's true that the NEX is sold as a still camera, and what a great still camera it is.  And yes it's true that  one might regard the video functions as a kind of "bonus" feature that is a "nice to have," but not worth too much time and attention if they don't work exactly as expected.    Although I do not agree with these assertions, even if I did, I would still find fault with my camera as is.  Here's why.

The behavior of the camera is paradoxical.  
  1. Why does it report thermal distress at temperatures that seem far below temperatures at which it will later operate with out a fuss?
  2. Why does it not report thermal distress prior to shutdown at higher temperatures?
  3. Why does the camera's surface temperature continuously rise in spite of serious counter-measures?
  4. Why does using the Memory Stick format seem to reduce the operating temperature?
It seems to me that even if the essential characteristics of the camera cannot be altered, some practical changes would make the camera more usable:
  1. Determine if the thermal distress indicator is functioning correctly.  
  2. Ensure the thermal distress indicator functions consistently.
  3. Determine if the camera triggers thermal shutdown appropriately.
  4. Provide guidance on maximizing record time (Examples: Memory Stick, AC adapter, waiting periods between recordings).
  5. Add a countdown timer to recording (from 30 minutes) so that users know that there  is a maximum record time independent of card size.
Improvement on theses items would make camera operation more predicable and the user experience more enjoyable.

IT IS TIME TO ASK SONY

It's  time for Sony to acknowledge this as an issue and work toward a solution.  I intend to send these comments to Sony in a letter.  I urge others to do the same or to simply file a question with Sony customer support 



Some have speculated that the camera heats up more when recording using a fully charged battery.  My tests indicate that this is not the case.  My tests on my camera show that the heating curve depends more on the state of the camera (cold or warm) than on the state of the battery.



SONY NEX OVERHEATING: Final Tests

I've collected more data than is shown here, but this sort of sums it up.  For analysis see my follow-up posting.

SD VERSUS MEMORY STICK &
BATTERY VERSUS AC



Click on image to enlarge.
Basically this graph shows that my NEX-5N runs cooler on AC and on Sony's best 32 GB memory stick.  Even so, the effect on continuous recording time is small.


TRYING VARIOUS TECHNIQUES TO REDUCE TEMPERATURE

I separated out this chart to enlarge it.  All the effects on surface temperature are quite small and can only be seen when zoomed in.

Heat sink refers to the arrangement pictured here.  The back label is removed, replaced by the thickest 3M thermal PSA AVAILABLE and topped with two heat sinks that cover the entire area under the LCD.




Click to enlarge



This graph shows that even the most drastic approach results in only small and temporary temperature reductions.  On the Sony support forums it is suggested to turn "Steady Shot" off.  In my testing on my camera this too made little or no difference.

Indeed, the only way that I was able to stabilize the camera's temperature was by placing it on a frozen gel pack.








Monday, March 5, 2012

NEX Testing Continues

While I await delivery of one more piece and try to arrange for thermal imaging of the camera recording AVCHD, I thought I'd share this picture of my NEX-5N in the "lab". I call it NEX ICU. An explanation of what you are looking at follows the image. (click image to enlarge)





You are looking at the NEX-5N on edge, mounted on a tripod, pointing down, with no lens attached.  The LCD is elevated.  The surface temperature sensor is taped into the flash threaded insert.  A small fan, about the size of a nickel, sits on the back plane. The HDMI, USB and AC adapter cables are connected after passing through a container containing a frozen gel-pack.

All these measures, to a greater or lesser degree, reduce the rate of temperature gain in my NEX-5N, recording video at the highest resolution, under my test conditions ; yet none of them individually, nor all of them and more, taken together, have been, thus far, able to stem the rise in temperature and the seeming inevitability of thermal shutdown.

I expect to have a final report on my findings in about a week.