bleirer

What is feel and how does ISO control it?

TriX Loc: Raleigh, NC

Another vote for “get the shot”. Of course it varies depending on the camera, but I have found that a good FF can deliver very acceptable results at ISO 12,800 (and even higher in a pinch), and a good crop body at 6,400 (and again, higher if necessary). While a lower ISO is certainly to be desired, users with late model cameras with good high ISO/low noise performance need not fear high ISOs if that’s what’s required. Better noise than a too slow SS resulting in a blurry shot.

Wallen Loc: Middle Earth

Shutter = Movement & Light
Aperture = Depth of Field & Light
ISO = Noise & Light

Ysarex Loc: St. Louis

Changing the shutter speed causes the rendition of motion to change between freeze movement and blur movement. (If movement is present).
Changing the shutter speed causes more or less light to reach the sensor.

Changing the aperture causes DOF to increase or decrease.
Changing the aperture causes more or less light to reach the sensor.

ISO is related to noise as it's related to exposure but changing ISO does not directly cause noise. Raising ISO in many cameras suppresses noise caused by another variable.
Changing ISO has no direct effect on how much light reaches the sensor. It will bias the camera meter which can cause either the shutter or aperture to change both of which change the light reaching the sensor but that's an indirect relationship that requires participation by the camera operator.

Presenting ISO in a way that suggests it acts on noise and light in the same causal way that the shutter acts on motion and light or the aperture acts on DOF and light can cause a lot of confusion.

ISO establishes a standard methodology for determining the brightness in the camera output image (typically JPEG) that results from a measured exposure of the camera sensor. ISO does not directly cause noise nor does it directly change the amount of light reaching the sensor.

Grahame Loc: Fiji

It really depends on what you consider as 'acceptable' noise. Personally, I never set any limit to ISO when in an auto mode for two reasons, a) I always watch what is happening with all settings, b) I want my camera ready for any eventuality.

As an example, but with a D800 here's a shot at ISO25600, I think the noise is acceptable based on two criteria, my standards and the image purpose/use. But, I have also taken many shots with the same camera at lower ISOs and considered the noise not acceptable.

1/60s, f/2.8, ISO25600

(Download)

Wallen Loc: Middle Earth

The statement was to express the changes that can be tangibly observe from a photographer's point of view. And it was as a reply as a different opinion from a previous post.
If i want to be true to function; ISO = Mean & Signal Amplification
but that would mean what to a photographer?

Your putting your own thoughts again as if that is being said and then correcting it with convoluted & contrasting examples.
Like this one "ISO is related to noise as it's related to exposure but changing ISO does not directly cause noise"
So it indirectly cause noise but it does not cause noise? Which is it?

And this one "ISO establishes a standard methodology for determining the brightness in the camera output image (typically JPEG) that results from a measured exposure of the camera sensor."
2 major problems here, 1 you always shoot RAW so what's that to do with ISO if it is for JPEG? Two, measured exposure of the camera is not standard and will keep changing even by the second. Why base a standard on non standard mean?

ISO = Noise & Light does not mean ISO cause noise and light as your explanation of what i mean.
I did not say that at all.
It simply state changing ISO will make you see a change in brightness and prominence of noise (because they are both amplified).
Also raising ISO do not suppress noise. "Raising ISO in many cameras suppresses noise caused by another variable" It's another system in the loop that does that. Like noise reduction on/off.

I'm sure this will be a long convoluted posts and riposte, so i'm hanging back and unfollowing the thread. Have fun.

nervous2 Loc: Provo, Utah

I too shoot Nikon and as I have gotten further into my dotage and my hands have become a bit more unsteady, I have considered changing my default ISO from 100 to maybe 400 to enable faster shutter speeds. I would not go anywhere near 6400 unless I really needed to do so to capture the image. Just my two cents.

jlg1000 Loc: Uruguay / South America

It is not only about noise, for each stop you increase ISO, you loose one stop of dynamic range.

Look at this chart https://www.photonstophotos.net/Charts/DXOPDR.htm

At ISO 6400 you'll have only about 4 or 5 useful DR stops so you'll loose a lot of detail and color rendering.

tcthome Loc: NJ

Are you happy with the photos? I'm guessing that your in auto ISO? I use auto ISO for changing light conditions which is usually when shooting wildlife. Most other times I'll use manual ISO & stay as low as I can.=Tripod for landscapes, night photos, etc. For my camera , I have max set at 3200. If I was to purchase a newer model camera today, it would probably handle a higher ISO noise better than what I get now with my current camera. If you can live with a photo from your camera at 6400 leave it there, if not lower it. You can clean the noise some in post.

SHWeiss

There are different types of noise. Iso noise is from signal amplification and is improved with noise reduction software. The sensor it’s self makes noise regardless of iso but can’t be seen if is is overcome with light in that sensor site (signal to noise ratios). Theses two types of noise are competing. So a iso100 shot that needs to be brightened a lot in post is often worse then using a higher iso. The best is ETTR at base iso which in low light will require a tripod and a long exposure.

jlg1000 Loc: Uruguay / South America

You can - partially - deal with noise in post, but you *cannot* deal wit loss of dynamic ratio. This is because of the 2nd Law of thermodynamics, you *cannot* bring back lis information.

First, you should determine if your camera is ISO invariant, as most modern cameras are. If so, then it is exactly the same to brighten in post as increasing ISO, besides that in post you can brighten only dark areas and do noise correction only there. And post noise algorithms are way better than those in camera.

So you have the best of both: the best DR and the lowest noise.

TucsonDave Loc: Tucson, Arizona

Its a matter of shooting where there is enough light to keep the ISO between base ISO and maybe 1200. BUT if it means the difference between getting the shot and not, than by all means get the shot at the higher ISO. Post processing can help mitigate the noise level to YOUR level of acceptance.

selmslie Loc: Fernandina Beach, FL, USA

The benefits of ISO invariance are misunderstood. At best, it only affects the highlights.

If you deliberately give away the top end of the dynamic range by shooting at base ISO you cannot make up for that with shadow recovery in post processing to make up for the gain that the camera did not apply.

For example, Capture One allows you to use the Exposure slider to bring the underexposed raw value by 4 stop (ACR allows 5 stops). That's done by multiplying all of the raw values by 16 (or 32).

But if the raw value is only 0, 1, 2 or 3 all you end up with is 0, 16, 32 and 48 (or 0, 32, 64 and 96). In other words, you cannot regain the lost values in between. They have to be made up in the software. There will be a loss of shadow tonality.

So you can't restore the missing DR in post processing. And if you couldn't increase the exposure there is nothing you can do about noise that you wouldn't need to do at a higher ISO.

All of this happens whether or not a camera is invariant. ISO invariance is a useless concept.

jlg1000 Loc: Uruguay / South America

The Sony cameras (and probably others) do *exactly the same thing as CaptureOne or ACR* but in the firmware of the camera.

Exmor sensors *do not have gain setting or processing circuitry* they send the raw data as seen by the sensor itself. Fox example, the sensor in the RX100 or the A6x00 increments one LSB for each 7 photons (statistical mean value) hitting the pixel. That is.

So, you can choose simplicity (set ISO to auto in the camera) or work (PP each photo), but the results will be the same. The benefit of PP is that you can *choose* what to enlighten... for example the shadows leaving the sky alone. If you increase ISO, then you risk blowing out the sky.

wmurnahan Loc: Bloomington IN

Your sunny day shots must be blown out. Do you like the look of the noise at 6400 because it looks like film grain?