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Does video capture heat up the sensor on new DSLRs?: News Discussion Forum: Digital Photography Review
With the D90 & 5D mk2 adding video capture I was wondering what affect both short term and long term this has on the sensors.
Since this is basically like continuous LiveView I would expect the sensors to get get quite hot during actual video recording - since they are known to do this with even moderate LiveView use.
Short term - heat build up causes noise in images (especially at higher ISOs)
Long Term - increased likelihood of sensor failure or degradation (to include hot pixels)
I'm just wondering if anyone can throw in some 'real' engineering facts to this discussion.
And 'good old' DPR opinions are always fun too :)
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... which can mean more noise under certain conditions;
It's unlikely, however, that you'd be shooting video whilst conditions demaned ISO 12K or better!
Video cameras have that sensor "hot" for many minutes, sometimes hours.
Nothing to worry about life-wise;
You'll never get several thousand hours of video time on a DSLR!
KP
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Hi,
Unless there is a major design flaw in the recall scale, there should not be any permanent damage due to prolonged main sensor usage.
The potential of temporary distraction would be some level of additional noise, but it is a subjective opinion about how much lower IQ can still be considered as acceptable.
Now I can't remember which DSLR, but I remember it has an "overheating warning" feature which basically stop the camera briefly to let it cool down.
BTW, heat sources can be:
- continuous sensor usage (Movie mode, Live Preview, etc.)
- Battery (especially the high energy density type)
- Processor/DSP (image processing, MPEG4 compression, etc.)
- backlight of the LCD panel
- ambient temperature
ccs_hello
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Quote: :
> BTW, heat sources can be:
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- continuous sensor usage (Movie mode, Live Preview, etc.)
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- Battery (especially the high energy density type)
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- Processor/DSP (image processing, MPEG4 compression, etc.)
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- backlight of the LCD panel
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- ambient temperature
Of all these, the sensor is among the smallest factors, if not the smallest factor.
Ambient temperature and backlight are the largest.
Sensor power consumption is measured in mW, and it is spread over a relatively large area.
If heat was a major problem, camera bodies would be white, and the LCD would be away from the sensor.
On the subject of backlight, it would be interesting to compare the change in sensor temperature over time on a Canon or Nikon live-view DSLR, and compare it to an Olympus E-3.
The E-3 has a swivel screen, so you can swing it away from the sensor and remove the heat from the backlight as a factor.
--
Seen in a fortune cookie:
Fear is the darkroom where negatives are developed
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Ken Quote: :
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... which can mean more noise under certain conditions;
It's
> unlikely, however, that you'd be shooting video whilst conditions
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Demaned ISO 12K or better!
Why do you consider this unlikely?
Admittedly, ISO 12K is extreme, but do you not think people might just occasionally want to shoot video in low light?
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Peter
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Power consumption from the sensor for the purpose of the comparison is not the subject.
It is "where" the heat is generated that matters the most.
If heat is generated locally right within the sensor, without bothering on thermal conductivity, the frined of heat will show up automagically uninvited :)
ccs_hello
Quote: :
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Of all these, the sensor is among the smallest factors, if not the
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Smallest factor.
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Quote: :
> Power consumption from the sensor for the purpose of the comparison
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Is not the subject.
It is "where" the heat is generated that matters
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The most. If heat is generated locally right within the sensor,
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Without bothering on thermal conductivity, the frined of heat will
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Show up automagically uninvited :)
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Ccs_hello
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Quote: :
> >
Of all these, the sensor is among the smallest factors, if not the
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> smallest factor.
In electronic devices you need power to generate heat.
The sensor is relatively large, which helps dissipate heat, and it doesn't take much power, so it can't generate much heat.
The backlight is right behind the sensor and power consumption is about 10x that of the sensor.
The body isn't far from the sensor and it is black, perfect for soaking up rays.
--
Seen in a fortune cookie:
Fear is the darkroom where negatives are developed
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> With the D90 & 5D mk2 adding video capture I was wondering what
>
Affect both short term and long term this has on the sensors.
Since
> this is basically like continuous LiveView I would expect the sensors
>
To get get quite hot during actual video recording - since they are
>
Known to do this with even moderate LiveView use.
They may be widely believed to get "quite hot" during live view operation, but I do not believe they are known to get "quite hot" even with extended live view use.
I think you will be hard pressed to find any reliable resource that supports the notion that sensors get "quite hot" during even moderate live view use.
Of course, when power is being used, something is going to heat up.
But that something is not likely to be the sensor.
So the key issue is that camera designers need to design the cameras to keep heat generating components away from the sensor.
But even then, they don't necessarily have to make heroic efforts.
Noise from a warm or hot sensor doesn't tend to show up unless you are using long exposures and to a lesser extent if you are using high ISOs.
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Long Term - increased likelihood of sensor failure or degradation (to
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Include hot pixels)
Pretty doubtful.
I think my computer CPUs are pulling 30-40 watts 24hrs, seven days a week and have been doing that for a couple years now.
They aren't failing due to the heat.
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I'm just wondering if anyone can throw in some 'real' engineering
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Facts to this discussion.
And 'good old' DPR opinions are always fun
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Too :)
Sensors do not draw much power.
Hence, they don't generate much heat.
I've done practical experiments with my E-330 where I left the live view on for 30 minutes continuously (It doesn't cut out for sensor heat as some people mistakenly believe.
It seems people sometimes mistake the battery saving Auto Power Off feature for live view overheat protection.) and the picture after aren't visibly any noisier than the ones taken before.
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Jay Turberville
http://www.jayandwanda.com
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... and I guess that more than a few clueless individuals have three grand lying about.
But still ... unlikely.
Most folks don't use ISO 1600!
KP
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Indeed, people will try anything...
Like making informed trade-offs in image quality to achieve the best results they can in given conditions with technology available to them...
And choosing to upgrade to new technology that will adapt better to said conditions...
Some people, eh?
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Peter
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Jay Quote: :
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I think you will be hard pressed
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To find any reliable resource that supports the notion that sensors
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Get "quite hot" during even moderate live view use.
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how about Yoshiyuki Nada, technical product manager for Olympus?
I think he is reliable.
He comments in the reference article about dealing with overheat of the cmos sensor when using liveview and that Olympus solved it.
"There are some DSLRs, which can show the live view using a main image sensor.
But these are limited in the time they can show the image on the LCD.
This is because to continue showing live view makes a sensor overheat and that affects image quality.
We solved this as well and the E-330 has no such limitation.
"
http://www.quesabesde.com/...
.../Olympus-E-330-Yoshiyuki-Nada,1_en_2256
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Scales Quote: :
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How about Yoshiyuki Nada, technical product manager for Olympus?
I
> think he is reliable.
Perhaps, but...
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He comments in the reference article about dealing with overheat of
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The cmos sensor when using liveview and that Olympus solved it.
First, he didn't say cmos sensor overheat, he said sensor overheat.
Second, explain the zillions of digicams that use their sensor full-time without overheating.
And that's typically with higher power consumption (CCD) so more heat, and spread over a smaller area which should make the problem worse.
Or the Sony R1, larger CMOS sensor than the E-330, no heat problem.
Or all the DSLRs with black bodies that very efficiently soak up the rays.
No need for live view to heat the sensor when you can have the sun do the job for you.
Yet somehow our DSLRs (even older ones) seem to work fine in sunlight.
--
Seen in a fortune cookie:
Fear is the darkroom where negatives are developed
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> I think you will be hard pressed
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> to find any reliable resource that supports the notion that sensors
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> get "quite hot" during even moderate live view use.
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How about Yoshiyuki Nada, technical product manager for Olympus?
I
> think he is reliable.
Well, nothing against Yoshiyuki Nada, but he's promoting an Olympus product versus competitor's products.
Do you really expect high levels of objectivity or a completely fair airing of advantage/disadvantages?
His statement was pretty obviously directed toward the Fuji and Canon DSLRs that first had primitive implemenations of liveview.
The comment isn't particularly relevant to current cameras.
His statement completely ignores the success of the APS-C sized CMOS sensor in the Sony R1 that predates the E-330 and seems to have had no problem with sensor heat.
http://www.dpreview.com/reviews/SonyDSCR1/page16.asp
Note that he says, "The E-330 has no such problem." In other words, the E-330 sensor does not get "quite hot" from live view use.
The E-330 is the first DSLR with a practical general purpose, full time live view feature.
Is there any reason to suspect that given the experience with the Sony R1 and many subsequent DSLRs that there is any real issue these days?
This goes back to my comment.
You will be hard pressed to find a reliable source that says sensors get "quite hot" during liveview.
I suppose I could have qualified the statement better by saying "current models" or recently developed models.
But given the context of the OP's concern, I didn't see the need and still don't.
There is no reason to suspect that a modern live view camera's sensor will be getting "quite hot" even in extended live view use.
Besides, CMOS is known for its low power consumption.
So why would we expect the sensor to be getting hot?
If you read the promo material on the original 7.5Mp nMOS sensor, the claim was that it has the large photodiode size of CCD with the low power consumption of ....
You guessed it ...
CMOS!! Low power consumption means lower heat generation from the sensor.
It is no surprise that Sony used CMOS in their R1.
http://www.dcviews.com/press/Olympus-Panasonic-MOS.htm
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He comments in the reference article about dealing with overheat of
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The cmos sensor when using liveview and that Olympus solved it.
Actually, Panasonic/Matsushita and Olympus take joint credit for developing the mirror box and sensor.
My bet is that Panasonic did most of the sensor work while Olympus did most of the mirror box work.
Either way, to say that Olympus solved the problem seems unlikely.
At best it was a cooperative effort.
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Jay Turberville
http://www.jayandwanda.com
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