[monochrome]

Had a certain pundit received a K-1 this might not have happened. I don’t engage any reviewer who has a click-based compensation schedule.

[YeOldePentaxian]

^^^

Are you perhaps referring to a pundit who said the K1 is only good for landscapes, and not good for sports because it won't track a white SUV head on in the desert?

[mikesbike]

Noise, which becomes evident at higher ISO settings, is indeed directly related to sensor temperature- nothing to do with the SR mechanism.

As to practical evidence, this thread brought to mind a POP Photo magazine test result some years ago of Canon's latest Rebel DSLR model, which at the time praised the new camera, but stated that only the Pentax K-r in the same class, had tested better in lower noise at higher ISO settings while preserving its superior resolution at those higher ISO ratings. The previous K-r test included praise for its performance regarding low noise and excellent detail preservation. As a standard, they always performed extensive testing in the field, in addition to lab testing, including evaluation of the Pentax SR effectiveness and overall performance at higher ISO ratings.

[stevebrot]

not good for sports because it won't track a white SUV head on in the desert?

The "S" in SUV does, after all, stand for "Sport"


Steve

[clackers]

^^^

Are you perhaps referring to a pundit who said the K1 is only good for landscapes, and not good for sports because it won't track a white SUV head on in the desert?

To put in a good word for him, after his very superficial go at this, later on he became impressed enough to call it his Camera of 2016.

[Ian Stuart Forsyth]

That is true and the assertion that the SR mechanism defeats the body as heat sync is hard to demonstrate or refute.

Any heat that is transferred from the floating sensor to the main body will have to pass thru the only contact between it and the body
From looking at a couple of older SR units there are only 3 points of contact between the 2 structures, these are small steel ball that are free to move around in a small area and are the only surfaces that will conduct the heat energy from the sensor. By design these 3 points of contact are to reduce the surface area as to minimize the friction( think of how small of an area makes contact when the balls dia. is less than 1 mm) while holding the sensor at its focus plane and to allow for the sensor to move freely with as little friction as possible. This in its self acts as a barrier to transferring heat.

I have a feeling that very little heat will transfer thru the surface contact between the SR and the steel sub plate of SR module. Most will be thru radiant heat.

As for sinking any heat from the steel sub frame to the metal shell of the camera body the only places that make contact are 3 screws along with there anchors on the bottom plate and 2 screws that attach the front plate and are located on the left side of the camera( with the K7 those 2 screws sandwich the rear plastic plate in-between the front plate and the sub steel frame). All other screws holding the metal body to the underling sub frame is into plastic.

[Kunzite]

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!)

But could you say if they're Canon users? That would be ironic

The internet pundits cannot begin to comprehend the effort done in keeping the noise under control. Nor are they trying to - they're not attempting to educate people, they're in the business of selling themselves as "experts".
In any case, "guessing" is useless (actually used if you want to reach a pre-defined solution, i.e. that your brand is better than some other - or the other way around, if you're a Pentaxian). We have one and only one reliable method, and that is to measure and observe.

In other words, we could simply look at the images we're taking, and see how there's no noise issue.

[redpit]

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.

Since Nikon prepares a camera with IBIS, prepare for the great somersault and the new scientific findings that clearly highlight the benefits of this innovative new technology has on IQ... It will be very funny to watch guys like Ken and the angry photographer flaunting what they were for so many years discrediting

Pentax has one of the cleanest and high IQ I've seen and that is the reason I'm so satisfied with my equipment and stuck with it from the first moment

[Fogel70]

Any heat that is transferred from the floating sensor to the main body will have to pass thru the only contact between it and the body
From looking at a couple of older SR units there are only 3 points of contact between the 2 structures, these are small steel ball that are free to move around in a small area and are the only surfaces that will conduct the heat energy from the sensor. By design these 3 points of contact are to reduce the surface area as to minimize the friction( think of how small of an area makes contact when the balls dia. is less than 1 mm) while holding the sensor at its focus plane and to allow for the sensor to move freely with as little friction as possible. This in its self acts as a barrier to transferring heat.

I have a feeling that very little heat will transfer thru the surface contact between the SR and the steel sub plate of SR module. Most will be thru radiant heat.

As for sinking any heat from the steel sub frame to the metal shell of the camera body the only places that make contact are 3 screws along with there anchors on the bottom plate and 2 screws that attach the front plate and are located on the left side of the camera( with the K7 those 2 screws sandwich the rear plastic plate in-between the front plate and the sub steel frame). All other screws holding the metal body to the underling sub frame is into plastic.

But is it any better on other brands DSLRs?
It's not like they use a massive heat sink on the sensor.
Nikon D600 Teardown - iFixit

---------- Post added 20-04-18 at 16:41 ----------

Since Nikon prepares a camera with IBIS, prepare for the great somersault and the new scientific findings that clearly highlight the benefits of this innovative new technology has on IQ... It will be very funny to watch guys like Ken and the angry photographer flaunting what they were for so many years discrediting

Pentax has one of the cleanest and high IQ I've seen and that is the reason I'm so satisfied with my equipment and stuck with it from the first moment

It is always fun with these comments from manufacturers that want to prove that not to implement something is best.

Like when Fuji said that their mount was to small to be compatible IBIS and that they did not have IBIS because they never compromise on IQ.
“Our highest priority is always image quality”. Interview with Takashi Ueno and Shusuke Kozaki from Fujifilm Japan. | FUJILOVE

Then two years later their mount is perfectly fine for IBIS, and IQ can be improved with help of IBIS.

[MossyRocks]

If you go ahead with that, I'd definitely be interested to see the results. There's absolutely no doubt that noise increases with sensor temperature.

The big question remains doe IBIS further increase it and with a first set of tests done last night out in the cool garage so far it looks to be a big nope. As you stated it seems that overall sensor heat is a bigger factor but that seems to mostly just show as an overall brightening of the image that reaches a peak and then drops and levels off. That said I am going to do a similar shoot tonight but with the SR settings inverted for each shot. Last night was 7 lens cap shots done the following way:
Camera had been in the cool garage all day (about 50 degrees)
All shots were 30 second shots at ISO 51,200 and were pictures of the inside of a lens cap for a 17mm SMC fish-eye Takumar
All shots were done on a tripod fully extended
The focal length was manually set to be 300mm.
For shots where SR was turned on the tripod was continuously tapped moderately hard with a wrench to introduce a fair amount of vibration that needed compensation.
The camera used was a K-3
High ISO noise reduction was turned off
ISO51200 was chose because it seems likely to be most likely to show thermal variations.
1 - SR off camera was powered on initially here and picture taken immediately. afterwards SR was turned off as we the camera
2 - SR on camera was powered on after a 10 minute wait and picture was taken immediately
3 - SR off right after previous picture
4 - SR off right after previous picture
5 - SR on right after previous picture
6 - SR on right after previous picture
7 - SR off right after previous picture

Now tonight I plan on doing the same set of tests (the camera is out in the garage again) but with SR settings inverted. I should be able to have some results Sunday or at the latest Monday night to provide. I have way too much going on it seems other wise would say I would post results tonight. The problem with this test is I don't have access to another camera with a similar sensor and of similar age that lacks IBIS so here the only meaningful results would be IBIS on vs. off. Since we are dealing with noise some worthwhile measurements to look at would be:
RGB average value
RGB median value
RGB STD deviation
per channel average value (might be interesting so why not)
per channel median value (might be interesting so why not)
per channel STD deviation (might be interesting so why not)
LZW tiff file size (this gets to the concept of entropy in information theory, a high entropy data does not compress much so this would be a good quick data point)
Maybe figure out some way to feed the image data into a tool like the diehard or dieharder battery of tests and get the test results.
Maybe also do some transformations on the data and subtract the first frame from all others and provide some data on new noise introduced. This may work for adjoining frames as well where the SR setting was changed so that may be worth looking at too.

[leekil]

It might be worth looking at the temperature of the camera in the EXIF data on the pictures you took, to see if there was any particular change over the course of taking your photos.

These are the temperature EXIF tags I see in one random K-3 photo:

Camera Temperature : 17 C
Sensor Temperature : 17.4 C
Sensor Temperature 2 : 17.4 C

[Rondec]

I don't understand why this would approach anything like mirrorless cameras issues. If you have a situation where you put the same sensor in a smaller camera body and then keep the sensor on all of the time because that's how your EVF works, wouldn't you see a lot more noise compared to an SLR design -- particularly in situations where conditions aren't ideal (eg really hot days, extended shootings sessions). At the same time, I haven't seen Sony folks complaining about increased noise compared to SLR cameras so my guess is that it is a small factor and not a big enough difference to notice in the final image.

[danielchtong]

Some people don't know what they are talking off, or are interested to do harm to other vendors because they are not so happy with their gear.

There is one real advantage of stabilization in the optics, with long lenses the optical viewfinder is stabilized too, but this could be solved when Tamron, Sigma will deliver their long optics for pentax with stabilization still in (hopefully they will do in the future again).

What about

• Pixelshift. (hasselblad, pentax, olympus.)
• astrotracing,
• rotary stabilisation.
• Sensor shift

Compare Nikon with Pentax both uses the same sensor(type) from sony, and deliver same quality.

For me as an pentaxian, I'll think Pentax do the better job. If there were a need for a change, or a second system (not at the moment) I would take Nikon, none of the others.

Agreed. The whole idea is just for badmouthing in camera SR (compared with in lens SR) which I think only Pentax still has a monopoly after Sony has shifted away

[Oakland Rob]

I don't understand why this would approach anything like mirrorless cameras issues. If you have a situation where you put the same sensor in a smaller camera body and then keep the sensor on all of the time because that's how your EVF works, wouldn't you see a lot more noise compared to an SLR design -- particularly in situations where conditions aren't ideal (eg really hot days, extended shootings sessions). At the same time, I haven't seen Sony folks complaining about increased noise compared to SLR cameras so my guess is that it is a small factor and not a big enough difference to notice in the final image.

Yeah, you can see an old example here: Noise comparison between hot and cold sensor (long exposure): Micro Four Thirds Talk Forum: Digital Photography Review

And if you go to astrophoto forums you'll see the problem discussed extensively, since it's big big problem with their long exposures.

I recall this sort of being discussed by DSLR folks who were complaining about heating in relation to video recording times; obviously mirrorless cameras have solved that to a certain extent, maybe because they are designed with that in mind, as are some DSLRs.

Here's an excellent test run by a Pentaxian and a Fuji: Image noise in DSLRs and mirrorless cameras...: Photographic Science and Technology Forum: Digital Photography Review

One very pertinent point he makes is this: given heat affects noise on all sensors, are all these tests we see by magazines, forums, etc, controlling for it?

I also wonder if the camera-brain tries to compensate for it; gotta be some reason it records sensor temp, maybe not just as a way to shut it off prior to overheating.

[stevebrot]

It might be worth looking at the temperature of the camera in the EXIF data on the pictures you took, to see if there was any particular change over the course of taking your photos.

These are the temperature EXIF tags I see in one random K-3 photo:

Camera Temperature : 17 C
Sensor Temperature : 17.4 C
Sensor Temperature 2 : 17.4 C

What they said ^ ^ ^ ...if the temps stay moderate, it makes almost no difference.


Steve