First outing for the D500

[DanK]

Indeed. It depends on the scene and how you are going to use the image. The smaller you display it, the less it matters. And if the scene doesn't require the full dynamic range, you can avoid or minimize problems by exposing to the right. And you can address one of the costs with noise reduction.

[Manfred M]

I had forgotten that Manfred has a different view of what is meant by 'exposure', as do others, which is why I folded.

In my world, exposure is proportional to shutter time and ambient luminance, and inversely proportional to f-number squared, but others think of exposure as the brightness of a developed image.

Ted - I suspect that most photographers would use my view of exposure as it is based on getting good data so that it can be used to create a good image. Every thing I was taught from my mid-teens onward talked about the length of exposure, the sensitivity of the photographic medium and the aperture on the lens.

English is a "messy" language and the same word or expression can have somewhat different meanings, depending on the context it is used in. The IT folks have a great way of describing this when discussing this in programing context; "overloading".

As CiC is a photography site, not an engineering site, I will generally stick to language that is widely used in photography A good camera exposure comes from controlling three variables; aperture, shutter speed and ISO.

Just to muddy things up even more, a lot of currently used photographic terminology comes from the film photography days. When working with film, there were two different exposures required; the capture process using the camera and the print making process, using an enlarger. When enlarging a negative (or positive) to make a print, the print medium, usually referred to as "paper" even when it was actually a sheet of resin (Cibachrome "paper"). Exposure is dependent on the sensitivity of paper, the position of the enlarger head above the easel (inverse square law impact) and of course the enlarger lens aperture. When we talk about exposure with regards to an image, that is the logic behind those words; a legacy process.

Frankly, it's not the only one. We write about dodging and burning too. In the darkroom, burning was accomplished by putting something in the way of the light between the lens and the paper on the easel. A hole or gap int the tool allowed the light hit a particular part of the paper to darken it. Dodging was the opposite. Here all the light was prevented from hitting parts of the paper, which let the print maker locally lighten that part of the image. Dodging and burning are common terminology in the digital darkroom, but these processes have nothing to do with the amount of light, but rather local darkening or lightening specific parts of the image.

So before we get too twisted up in terminology, let's ensure that it is appropriate to the majority of readers at this site. Photographers may use the same words as engineers, but often it has a slightly different context. Unless I am discussing something quite technical here, I will stick to terminology used by photographers, even those of us who are engineers might not agree with them.

A few more thoughts on Dan's comments:

I agree to some extent any of the three exposure adjustments have real world consequences:

Changing aperture will impact image sharpness; a wide open lens will can give us a shallow depth of field, but not optimal resolution. A lens that has been stopped down to f/22 or smaller will give us wide depth of field, but not optimal sharpness as diffraction will impact sharpness. Shooting in the "sweet spot" of the lens (usually achieved at two or three stops lower than wide open) may optimize sharpness, but may not be appropriate for the depth of field we are trying to accomplish.

Shutter speed has a similar impact. A very fast shutter speed will freeze all motion, whether we want this or not. We sometimes throw a neutral density filter over the lens to enhance elements of motion. Likewise, too slow a shutter speed will give us motion blur or camera movement, which may or may not be desirable.

Finally changing the camera's gain (i.e. ISO) will impact digital noise, dynamic range and colour bit depth; all decisions we need to understand and make tradeoffs against. That being said, the one area where we have seen tremendous strides with sensor technology advancements. I can take images where digitial noise is not a significant issue with my 7 year old camera that I could never have contemplated with my 12 year old one.

[xpatUSA]

Ted - I suspect that most photographers would use my view of exposure as it is based on getting good data so that it can be used to create a good image. Every thing I was taught from my mid-teens onward talked about the length of exposure, the sensitivity of the photographic medium and the aperture on the lens.

<OK>

Finally changing the camera's gain (i.e. ISO) will impact digital noise, dynamic range and colour bit depth; all decisions we need to understand and make tradeoffs against. That being said, the one area where we have seen tremendous strides with sensor technology advancements. I can take images where digitial noise is not a significant issue with my 7 year old camera that I could never have contemplated with my 12 year old one.

To lighten things up a bit, here's a test I did with a 2012 model ISOless "Merrill" Sigma compact, FYI:



Ignore the color casts.

As can be noisily seen, some sensors are still lagging and currently the future of the Foveon is somewhat moot for various other reasons.