Exposure is not how dark or how light an image looks!

You could be routinely underexposing from ETTR by two stops and getting noise quality that you consider acceptable. If that were true, you could get the same noise with a smaller sensor and save your self a lot of money.

You could see noise in your image and be unsure about how to fix it. Looking at the raw data could tell you why your image is noisy and what to do about it.

I can't count the number of times people have told me that they are masters of ETTR and they know it by looking at the histogram in Lr.

One can also see (or not see) poor definition in shadows or distorted colours and be sure this is how it should be, or spend money on a camera that promises half a stop of "DR" improvement, f/1.4 lenses they nearly never use fully opened, etc. ;)

From a noise point of view, you can turn your full frame MILC or SLR into a micro four-thirds camera by underexposing by two stops, into a point-and-shoot by underexposing four stops, or into an iPhone by underexposing by six stops. Underexposing in this case is relative to ETTR.

Thanks!

Hear, hear. You are preaching to the choir.

It's very possible if there are red flowers in the scene.
Don

Consider a photographer working in the field. I choose an f-stop I believe will deliver an acceptable depth of field (DOF) and a shutter speed that will render movement to my liking. I know that those camera settings, combined with the available light, will determine exposure.

Based on an ISO of 400 producing a pleasingly light image and their camera's base ISO of 100, I also conclude they camera is roughly 2-stops below an exposure that would saturate the sensor without blowing out highlights.

Several questions go through my mind. What's an acceptable margin for error when assessing DOF and motion blur? The LCD display offers finite image scale and resolution. At best, it approximates how those image qualities will present on a larger monitor at home. I may consider it prudent to err on the side of settings that over deliver at least to some extent.

What does my experience photographing similar scenes tell me about settings that will both fulfill my desired goals for DOF and rendering of movement while capturing enough light to minimizing the negative impact of shot noise on the final image? As I gain experience and confidence in my field assessment, the narrower the margin of error I may require.

For example, using my lens at f/5.6 will deliver an acceptable DOF and images having good sharpness of a bird in-flight. I can leave the lens wide open (f/5.6), get the DOF and image sharpness I want and use that setting to maximize exposure.

I make use of tools and resources that are readily available and have proven to be of use in the past. In the field, I rely on knowledge, experience, and the camera's tools. At home, I can add Lightroom Classic's tools to the mix.

Assuming my ultimate goal is to produce a pleasing, high quality image, how would adding RawDigger to my existing workflow contribute to that effort. Where would it fit amongst my other tools?

You said "Based on an ISO of 400 producing a pleasingly light image and their camera's base ISO of 100, I also conclude they camera is roughly 2-stops below an exposure that would saturate the sensor without blowing out highlights."

You are drawing conclusions about how much headroom you have in the raw file based upon how nice the JPEG preview image looks? In your scenario, I don't see how you know much about the raw data. Actually looking at the raw data after the shoot would give you knowledge that you could apply next time you were in a similar situation.

I'm assuming the other questions beside those in the last paragraph are rhetorical.

Have you ever looked at the raw data for your exposures? If so, were you ever surprised at what you saw?

Also, I think your goal for the raw file should be not to produce a pleasing, high-quality image, but to produce a file from which you can construct such an image. The distinction is important.

I guess we can include the concepts of under and over exposure here somewhere. Never mind, someone already mentioned it. Is there a way to delete a post?

i own a portrait studio and hold workshops occasionally and your saying that one should just discuss shutter and aperture only ;-). please explain to me how shutter speed has a great meaning shooting in a studio situation ? correct me if im wrong, virtually none.

I am not saying that one should discuss aperture and shutter only. I said that that was common among photographers. I think it is an unfortunate elision, although understandable and timeworn.

I don't know about your studio, but mine has a lot of Wescott and Aputure continuous lights. Shutter speed is part of the determination of exposure when using those lights.

I use strobes in my studio. Shutter speed is not a critical factor in these exposures. I normally shoot around 1/125. If I changed the speed to 1/30, it would not make a significant difference in the exposure.

In this particular context, the important factors are subject lighting and aperture. There's a range of shutter speeds that will yield essentially the same results.

Sure. I don't know where I implied otherwise.

i dont use any continuous lights for portrait work and no no one that does either. i only use continuous lighting is for my extreme macro work with live bugs. can you post any camera manual ever produced in the last 100 years where "exposure" is defined as shutter speed an aperture only ?

I never said that camera manuals stated that exposure was a function of shutter speed and aperture only. I said that it was common among photographers, when asked what the exposure for an image was, to give the f-stop and the shutter speed, ignoring the scene luminance.

same , if i want to still motion i use strobes 1/2000 sec :-)