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04-18-2018, 01:12 PM - 1 Like   #16
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It probably not to hard to also prove that using optical image stabilization lead to noisier images.

Optical image stabilization require extra lens elements in a lens, and in every lens element a small amount of the captured light is lost. So in lenses with optical image stabilisation a littles less light will reach the sensor, than if the lens where designed without optical image stabilisation.

But the easiest thing is to prove is that without any type of image stabilisation the images will be most noisy, as you then need to increase ISO to prevent camera shake.

04-18-2018, 01:33 PM   #17
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QuoteOriginally posted by MossyRocks Quote
This sounds like an interesting experiment to conduct since it would basically be trying to see how thermal noise affects the sensor. I might have to conduct an experiment tonight if I can figure out a good set of tests that might produce meaningful results.
Mostly I think it's an effort to see 1) how much SR design affects thermal dissipation and the ability to keep the sensor cool, and 2) does using SR add any appreciable heat over and above the heat generated by just using the sensor?

Doing a test with and without SR on Pentax gives the answer to number 2 - but not number 1.
You would need a non-pentax with the same sensor in it to answer question 1 and even then you can't fully be sure that the other design aspects of the camera (amplifiers, power supplies, etc were not equally or more responsible for any delta in condition 1.
04-18-2018, 01:51 PM - 1 Like   #18
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QuoteOriginally posted by Lew Dite Quote
I ask because certain Internet pundits have made the claim that the images from cameras with in-body image stabilization (IBIS), which includes all current Pentax DSLRs and many mirrorless cameras, tend to be noisier than images from cameras without it (e.,g. Nikon and Canon DSLRS). One claimed cause of this supposed increased noise is faster heating of the sensor (because the sensor's carrier is thermally isolated from the rest of the camera), which if real would primarily affect video and live-view use of the camera where the sensor readout is constant. Another claimed cause I have read is electromagnetic interference. Of course, no actual evidence is every provided for these claims nor are the exact mechanisms that supposedly increase noise ever fully explained. There's just a lot of hand waving.
I doubt that the images would have more (practically visible) noise, but the cameras themselves are certainly a bit noisier

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04-18-2018, 02:19 PM   #19
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QuoteOriginally posted by UncleVanya Quote
Mostly I think it's an effort to see 1) how much SR design affects thermal dissipation and the ability to keep the sensor cool, and 2) does using SR add any appreciable heat over and above the heat generated by just using the sensor?

Doing a test with and without SR on Pentax gives the answer to number 2 - but not number 1.
You would need a non-pentax with the same sensor in it to answer question 1 and even then you can't fully be sure that the other design aspects of the camera (amplifiers, power supplies, etc were not equally or more responsible for any delta in condition 1.
That is true and the assertion that the SR mechanism defeats the body as heat sync is hard to demonstrate or refute. About all we can look at is whether the effort to stabilize increases the thermal load.


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04-18-2018, 02:25 PM   #20
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Um, maybe I'm being Capt Obvious here but did these Druids of Pixel Peeping take into account that with SR on one could shoot with more light? I mean even if at the same exact shutter, ISO, and aperture if SR gave a bit more noise, I'd suggest the ability to get more light would make that a distinction without a difference. Or am I just misunderstanding?
04-18-2018, 02:34 PM - 1 Like   #21
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I could really care less, though I haven't personally seen any evidence either way.

To me this is pretty much a tempest in a teapot since noise reduction software is built into most cameras and sometimes can't be turned off even if you were so inclined.

In addition there has been world class noise reduction software available for Photoshop and other programs for as long as I have seriously considered using digital.

If you need to use your camera at the highest ISO limits on a regular basis to get your photo then you will almost certainly be using the latest noise reduction software available.

For the rest of us...oh well.
04-18-2018, 02:37 PM - 2 Likes   #22
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My understanding is that even when SR is off, the mechanism is still running to hold the sensor in place, so it seems tough to isolate any heat effects. I'd also guess for stills the difference is marginal at best, so you're going to need pretty tight controls to see if there's any difference at all.

I think you'd need very careful testing with the k100d vs k110d to say anything conclusive (I think they're the only body pair that differs only by the SR feature), but this might not even say anything about more recent implementations. I suppose you could hack apart a camera to disable SR using wire cutters and use superglue to hold it in place, but....eh, how much effort is worth trying to debunk people who really don't matter to me?

04-18-2018, 02:44 PM   #23
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QuoteOriginally posted by Oakland Rob Quote
Um, maybe I'm being Capt Obvious here but did these Druids of Pixel Peeping take into account that with SR on one could shoot with more light? I mean even if at the same exact shutter, ISO, and aperture if SR gave a bit more noise, I'd suggest the ability to get more light would make that a distinction without a difference. Or am I just misunderstanding?
I don't think you're misunderstanding. However...

Let's say you're shooting a moving car in motorsport with a 135mm lens, and you're using a shutter speed of 1/160s because that gives you the right amount of motion capture plus background blurring as you pan (the shutter speed being part of your "creative control")... the fact that SR would let you shoot that lens at 1/50s is all well and good, but not useful creatively in that situation.

Of course, you could argue that in this situation, you just turn the SR off, since 1/160s plus 135mm is fine using the reciprocal rule... but who wants to keep switching SR on and off mid-shoot?

That said, even if there is a small noise-disadvantage to using SR (and I remain skeptical), I don't believe it's remotely significant. I shoot at high ISO quite regularly with SR enabled, and I've never been unhappy with the performance...
04-18-2018, 05:10 PM - 1 Like   #24
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QuoteOriginally posted by UncleVanya Quote
Mostly I think it's an effort to see 1) how much SR design affects thermal dissipation and the ability to keep the sensor cool, and 2) does using SR add any appreciable heat over and above the heat generated by just using the sensor?

Doing a test with and without SR on Pentax gives the answer to number 2 - but not number 1.
You would need a non-pentax with the same sensor in it to answer question 1 and even then you can't fully be sure that the other design aspects of the camera (amplifiers, power supplies, etc were not equally or more responsible for any delta in condition 1.
Yeah, that's the problem. Even if SR could theoretically lead to faster heating of the sensor over time, good design could well mitigate it (e.g., maybe the design of Pentax's SR actually does ensure heat dissipation from the sensor to the metal chassis and metal body - I've never seen an analysis of the hardware involved). So design matters and all camera designs are different (within limits).

Of course, in the end the only thing that matters is the final result. If the sensor noise for the camera is low then it shouldn't matter if SR adds additional heat, hence noise, or noise from EMI (the latter seems unlikely to me). Still, it would be nice to be able to refute the claims, even if only with anecdotal evidence.
04-18-2018, 06:51 PM - 1 Like   #25
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QuoteOriginally posted by Lew Dite Quote
Still, it would be nice to be able to refute the claims, even if only with anecdotal evidence.
Without my own study to provide the empirical data to back it up , I feel like when I see these types of claims of X versus Y, they just happen to be the type of thing you can't find any evidence to back up, but they make good click bait. Funny thing about that.
04-18-2018, 08:33 PM   #26
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The originally stated hypothesis (as I interpreted it from the OP), is that the SR cameras are more heated not due to the *use* of the SR mechanism, but that the design requirements of the SR mechanism result in a sensor that is less physically connected to the rest of the camera. In this case, the rest of the camera has less capacity to act as a heat sink to prevent the sensor from heating up as much or as fast.

But in any rate, the test for this increased noise should be to easy no matter the exact theoretical mechanism for the extra heating. Just take a photo with a newly-turned on camera that hasn't been used for long enough for it to completely cool down. Then use the camera for a while, to get it heated up, and then take another picture to compare to the first one. Or if you really want to be more extreme, you could cool the camera somewhat initially so there is a greater temperature difference. But that might be too much unlike the normal usage case to really represent real-world cases.
04-18-2018, 09:14 PM - 2 Likes   #27
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QuoteOriginally posted by leekil Quote
But in any rate, the test for this increased noise should be to easy
Yes, but I wouldn't hold my breath for these Internet experts to do that, Leekil.

That would be substance rather than style!

If they're Canon, Fuji or Nikon shooters themselves rather than Pentax, Olympus or Sony, they'd have no motivation to see the real effect, either.
04-18-2018, 09:44 PM - 1 Like   #28
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In Pentax SR the sensor is mounted on a quite large metal frame that sits between two metal frames that are connected to the body. So this might actually be better for cooling the sensor than on many cameras without IBIS.

SR itself may also improve cooling a little as when sensor is moving the airflow will increase over the sensor.
04-19-2018, 06:51 AM - 1 Like   #29
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QuoteOriginally posted by leekil Quote
The originally stated hypothesis (as I interpreted it from the OP), is that the SR cameras are more heated not due to the *use* of the SR mechanism, but that the design requirements of the SR mechanism result in a sensor that is less physically connected to the rest of the camera. In this case, the rest of the camera has less capacity to act as a heat sink to prevent the sensor from heating up as much or as fast.
Yes, that seems to be what the "internet pundits" I have read are saying. (I'm not naming them because facts should be independent of personalities...but I can if it adds to the fun!)

QuoteOriginally posted by Fogel70 Quote
In Pentax SR the sensor is mounted on a quite large metal frame that sits between two metal frames that are connected to the body. So this might actually be better for cooling the sensor than on many cameras without IBIS.

SR itself may also improve cooling a little as when sensor is moving the airflow will increase over the sensor.
Both are good points. Furthermore, if those metal frames roll around on tiny ball bearings (that's what it sounds like to me!) when they are pushed and pulled magnetically (is it like a voice coil in a speaker?) then there could still be some thermal conduction to the body of the camera, which in the case of the K-3(II), KP and K-1 (and K-5, K-7, etc) is almost all metal. [I have read that the sensor floats magnetically. But if that were so why do I clearly hear noise when the SR is active (e.g., during live view with telephoto lens)?]

Frankly, if the sensor were indeed thermally isolated from the rest of the camera,I would expect that the camera would have a tendency to shut down from overheating before the 25 minute time limit is reached while recording video (during which the sensor is constantly being read but the SR is not active). Has anyone ever reported that for Pentax K series DSLRs?

Last edited by Lew Dite; 04-19-2018 at 07:37 AM.
04-19-2018, 09:45 AM - 3 Likes   #30
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QuoteOriginally posted by BigMackCam Quote
I don't think you're misunderstanding. However...

Let's say you're shooting a moving car in motorsport with a 135mm lens, and you're using a shutter speed of 1/160s because that gives you the right amount of motion capture plus background blurring as you pan (the shutter speed being part of your "creative control")... the fact that SR would let you shoot that lens at 1/50s is all well and good, but not useful creatively in that situation.

Of course, you could argue that in this situation, you just turn the SR off, since 1/160s plus 135mm is fine using the reciprocal rule... but who wants to keep switching SR on and off mid-shoot?

That said, even if there is a small noise-disadvantage to using SR (and I remain skeptical), I don't believe it's remotely significant. I shoot at high ISO quite regularly with SR enabled, and I've never been unhappy with the performance...
I agree.

And BTW, I seem to recall reading something from Pentax that SR II is compatible with panning, ie it will control in the other axes of motion without interfering with the shot of the moving object. A cool feature of this (since some in-lens stabilization systems can do this as well) is that it compensates for roll, which I think is not on for OIS. And I know that I tend to roll the camera when doing a panning shot. Be cool to see some shots testing that. And again, I'd trade that for some noise any day.
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