[pschlute]

The 80% claim is nonsense.

I understand the desire to use a low iso. That is why fixed iso is available. But shutter speed and aperture also play a part in image quality. Getting the balance of the exposure triangle correct is what marks our cameras out versus an iPhone.

There is a reason you can see your parameters in the viewfinder as you take your shot and adjust modes and settings accordingly if you don’t like what the camera gives you

[biz-engineer]

I got that, but I don't think 80% of all the pictures taken are in those specific conditions:

The 80% claim is nonsense.

All still image that were taken with an ISO setting between 200 and 800 could potentially have been taken at ISO100 is the camera lowered the shutter speed to a value below the reciprocal of focal length when knowing that SR was enabled. If I look at exposure settings in exif files of many photographs in Flickr, a lot of exposure settings are far from being the best possible settings. I've seen things like shutter speed 1/500th and ISO1600, while it could have been 1/25th at ISO100.

[volley]

All still image that were taken with an ISO setting between 200 and 800 could potentially have been taken at ISO100 is the camera lowered the shutter speed to a value below the reciprocal of focal length when knowing that SR was enabled. If I look at exposure settings in exif files of many photographs in Flickr, a lot of exposure settings are far from being the best possible settings.

Probably your thinking is way too focused on low ISO as the only parameter for ultimate IQ.
Obviously your initial "... 80% of all pictures could be improved" is (sorry) nonsense. Even if camera shake is reduced by IBIS you still would see potential blurr caused by subject moving (how should the camera in whatever auto setting know?) or wind moving the subject etc. etc.
So there would also be many shots that seem to have a better IQ (whatever that is) when shot at let's say 1/250 @ ISO800 compared to 1/30 with IBIS @ ISO100. There is more than one parameter influencing perceived IQ and it is up to the photographer to find the best setting for the subject.

If you really want best possibly IQ for stationary subjects there is a very effective and ultimate solution: use a good tripod!!

[pschlute]

All still image that were taken with an ISO setting between 200 and 800 could potentially have been taken at ISO100 is the camera lowered the shutter speed to a value below the reciprocal of focal length when knowing that SR was enabled If I look at exposure settings in exif files of many photographs in Flickr, a lot of exposure settings are far from being the best possible settings.

I am sure many are taken at less than optimum ISO but 80% ?

Now if the camera did automatically use say 4 stops lower shutter speed as you suggest, how many of that 80% will now show :

1. Subject movement
2. Diffraction (due to too small aperture)
3. poorer sharpness (due to aperture moving away from ideal MTF)

If I put my camera in P mode to take some street scene shots, and instead of 1/60 the camera gives me 1/4 second my shots are going to be blurry.
If I put my camera in P mode to take some landscape shots and the camera uses 1/4 and f32 (instead of 1/60 and f8) the diffraction has ruined my shots.

It is very easy to over think solutions to perceived problems when you are just adding more uncertainty into the mix.

[biz-engineer]

Obviously your initial "... 80% of all pictures could be improved" is (sorry) nonsense.

Why is it non sense? Should I collect 10 000 exif and make a statistic?

---------- Post added 21-11-19 at 15:34 ----------

Why all this opposition to improve?

SR is basically a system such that any camera movement is actively reduced by the camera. For example, if a shutter speed of 1/100 at 100mm focal length is normally required to achieve proper image sharpness with 1mm shake of the camera, the SR servo reduces the effect of 1mm camera shake in such way that a shutter speed of 1/10th s. shutter speed is enough to produce the same image sharpness as the one achieve at 1/100th s. shutter speed without SR. Why should I not want to take advantage of SR for every case where SR is effective?

Why not even have the camera measure shake with its built in accelerometer and automatically enable SR? Why would I not want multiple stops of improvement automatically exploited by my DSLR firmware?

[fs999]

SR is basically a system such that any camera movement is actively reduced by the camera. For example, if a shutter speed of 1/100 at 100mm focal length is normally required to achieve proper image sharpness with 1mm shake of the camera, the SR servo reduces the effect of 1mm camera shake in such way that a shutter speed of 1/10th s. shutter speed is enough to produce the same image sharpness as the one achieve at 1/100th s. shutter speed without SR. Why should I not want to take advantage of SR for every case where SR is effective?

You're right there should be an option in Auto ISO parameters like Lower with SR...

[volley]

Why is it non sense? Should I collect 10 000 exif and make a statistic?

Yes, please. I appreciate your offer.
Though uploading 10.000 pictures shot with (what you believe are) wrong settings and then shot with your optimised settings might be a challenge ...

---------- Post added 21-11-19 at 15:34 ----------

Why all this opposition to improve?

SR is basically a system such that any camera movement is actively reduced by the camera. For example, if a shutter speed of 1/100 at 100mm focal length is normally required to achieve proper image sharpness with 1mm shake of the camera, the SR servo reduces the effect of 1mm camera shake in such way that a shutter speed of 1/10th s. shutter speed is enough to produce the same image sharpness as the one achieve at 1/100th s. shutter speed without SR. Why should I not want to take advantage of SR for every case where SR is effective?

Why not even have the camera measure shake with its built in accelerometer and automatically enable SR? Why would I not want multiple stops of improvement automatically exploited by my DSLR firmware?

I am not sure if you have read what I wrote earlier. At least I don't see that this response is referring to what I have written. But fair enough.

I'm aware what IBIS is (I'm also an engineer - not "biz-" but mechanical). But what makes you think the "1/focal length" rule of thump (it's nothing else) has something to do with "1 mm camera shake"?? It is simply based on the experience that when an average photographer uses this rule for cameras with 35mm film or sensor, the circle of confusion resulting from camera movement still gives acceptably sharp pictures (for an average viewer, probably not for a pixel-peeper)..
Some photographers have significantly more steady hands or better technique, some are unable to get sharp shots at the same conditions.

Again, ultimate IQ requires selection of optimum aperture and a tripod.

[othar]

All still image that were taken with an ISO setting between 200 and 800 could potentially have been taken at ISO100 is the camera lowered the shutter speed to a value below the reciprocal of focal length when knowing that SR was enabled. If I look at exposure settings in exif files of many photographs in Flickr, a lot of exposure settings are far from being the best possible settings. I've seen things like shutter speed 1/500th and ISO1600, while it could have been 1/25th at ISO100.

1/500th and ISO1600 can be a reasonable choice depending on the lens you use and the subject you photograph, but that might be beside the point at the moment.
I think you overrate the importance of low ISO a little (I am not saying it can't ruin your images but not as fast as you make us believe here). While I agree there are certain ISO values I don't wanna cross with my camera in normal circumstances I also won't push to slow shutter speeds just to get as low as ISO 100 no matter what.
Up to ISO 800 there is no noteworthy sensor noise that can't be dealt with in post with my camera in my opinion. ISO 1600 is the first step I usually try to stay below and if the light is very unkind I use up to ISO 3200 and that is with a 6 year old camera model (K-3).
I was at a talk of Martin Bissig (action photographer from Switzerland) not long ago and he showed a picture that was printed over a double page in a magazine and it was taken at an ISO value of 3200. So ISO 800 is really nothing I would loose sleep over.

Edit: As volley pointed out the 1/focal lenght rule is just a rule of thump and additionally it originates from film days. With pixel densitiy getting higher and higher and exceeding film resolution it has to be modified for some photographers to 2 times the focal length or even more depending on how steady (or not) they can hold the camera (without SR)

[pschlute]

For example, if a shutter speed of 1/100 at 100mm focal length is normally required to achieve proper image sharpness with 1mm shake of the camera, the SR servo reduces the effect of 1mm camera shake in such way that a shutter speed of 1/10th s. shutter speed is enough to produce the same image sharpness as the one achieve at 1/100th s

Nope. People; dogs; trees; leaves on the ground blown by a gentle breeze all will be blurry at 1/10.

That is not an improvement.

[biz-engineer]

Nope. People; dogs; trees; leaves on the ground blown by a gentle breeze all will be blurry at 1/10.That is not an improvement.

There are a lot of photos that don't contain dogs, and trees.If I set the camera in M mode so that to take advantage of SR, have a lower shutter speed and lower ISO, it works. If get it would also work if the camera exposure algorithm does automatically what I do manually. It would be interesting to know if Sony and Nikon have implemented what I want to have.

[pschlute]

There are a lot of photos that don't contain dogs, and trees

What about people ?

If I set the camera in M mode so that to take advantage of SR, have a lower shutter speed and lower ISO, it works

With a static subject of course it does. Is that an argument for putting it in the automation ?

Using a low ISO is not rocket science, you are making it all far too complicated, sorry.

[stevebrot]

This is happening. The camera does read and use the lens focal length (e.g using a zoom lens) as one of the conditions to set shutter speed.

Cannot reproduce in P mode (blank wall test) on my K-3 using auto-ISO and "Standard" (default) auto-iso sensitivity with prime lenses at 28, 50, 85, and 120mm focal lengths. Substituting a variable aperture zoom*, at 17, 28, 50 and 70mm, shutter speed varied according to aperture reported by lens with consistent (identical) LV100 across all focal lengths and auto-ISO = 200. This behavior is expected for variable aperture zooms.

Addendum: Repeating with fixed ISO 200 with the variable aperture zoom produced the identical numbers.


Steve

* Unable to test with constant aperture AF zoom...no such own...

[biz-engineer]

Cannot reproduce in P mode (blank wall test) on my K-3 using auto-ISO and "Standard" (default) auto-iso sensitivity with prime lenses at 28, 50, 85, and 120mm focal lengths.

The lens aperture can't be set as a constrain in P mode. Using the Av mode allows to set the lens aperture as a constrain, setting a aperture value higher than the min of the zoom lens, for instance f5.6 or f8 would remain constant accross the zoom range of your Sigma 17-50 f2.8:4. In Av mode + Auto ISO, the camera would set shutter speed around 1/17th s. at 17mm, 1/30th s. at 30mm and 1/50th s. at 50mm, with ISO value gradually increasing as the shutter speed increases.

---------- Post added 21-11-19 at 22:03 ----------

Using a low ISO is not rocket science, you are making it all far too complicated, sorry.

Yes, I'm making it too complicated because the camera doesn't do what I want it to do. When I tried to have the camera lower the shutter speed below 1/FL, I tried everything and I failed. No way, my Pentax K1 is like a lazy Donkey, no even showing it a carrot or a stick will ever change its auto-exposure behavior.

[pschlute]

Yes, I'm making it too complicated because the camera doesn't do what I want it to do

The camera cannot make a cup of tea either, that does not make it wrong.

When I tried to have the camera lower the shutter speed below 1/FL, I tried everything and I failed

We seem to be going around in circles. The modes like P and AUTO (green) are compromises. They give the results the Pentax engineers feel most folk would want. If I used P mode I would not want it to behave the way you do when SR is enabled for the reasons I gave in previous posts. You have the answer already, don't use the auto modes, use a mode where you can set the shutter speed you want.

[MarkJerling]

This is happening. The camera does read and use the lens focal length (e.g using a zoom lens) as one of the conditions to set shutter speed. The way to see how the lens focal length changes the value of shutter speed is to use a uniform wall evenly lit, and zoom in and out the lens to see if the shutter speed is changing. I've done that experiement, and I've seen the camera adapt shutter speed to lens focal length to around 1/FL, e.g 50mm => shutter speed = 1/50th s.; 100mm => shutter speed = 1/100th s.
Now if the ISO hit the min possible value or max possible val, the camera won't change the shutter speed even if the lens FL is changed, because the objective of the AE algorithm if to expose correctly in the first place. If A is fixed, ISO is auto and T is auto, the camera will adjust ISO so that to have T = 1/FL.[COLOR=Silver]

Cannot reproduce in P mode (blank wall test) on my K-3 using auto-ISO and "Standard" (default) auto-iso sensitivity with prime lenses at 28, 50, 85, and 120mm focal lengths. Substituting a variable aperture zoom*, at 17, 28, 50 and 70mm, shutter speed varied according to aperture reported by lens with consistent (identical) LV100 across all focal lengths and auto-ISO = 200. This behavior is expected for variable aperture zooms.

Addendum: Repeating with fixed ISO 200 with the variable aperture zoom produced the identical numbers.


Steve

* Unable to test with constant aperture AF zoom...no such own...

I'll try a test later today. To me, the logical test would be to use a modern zoom with electronic contacts and an old zoom without electronic contacts where the camera can't know what lens is mounted and see if they behave differently, assuming similar focal ranges and apertures.