"The proper exposure"

www.fastrawviewer.com/blog/red_flowers_photography

Thanks, that is a good writeup.

Now that I have MacOS instead of Linux, I will download and purchase.

I run it using Linux and wine ;)

Proper exposure is situational. Sometimes the proper exposure will mean maximum light on the sensor. Sometimes the proper exposure will mean the one that results in pleasing lightness without processing. Sometimes it will mean a given amount (or lack) of blur or a certain DOF. I think the problem is when people blindly insist there is only one proper exposure for a given scene.

Of course to understand when an exposure is proper or optimum one has to understand what exposure means and that is clearly a problem for some.

Why not?

Replicate means "the action of copying or reproducing something". Granted you can't exactly replicate a scene with a camera due to technical limitations, like the fact that most photographs are in two dimensions (and if that's what you mean then we're in agreement and no further discussion is necessary). I would say you can certainly make a reasonable replication of what you see in front of you in a picture, would you disagree?

While I have no doubt that fastrawviewer is an excellent program because I have read much of the libraw source code, I choose to use free software as much as possible. Some of that software is free as in free speech and other is only free as in free beer. I would not discourage anyone from purchasing fastrawviewer, even though I see no need for it myself. I expect that many will find fastrawviewer very useful. There is more than one way to do things.

Since I have a Canon camera, I use the Canon DPP software on my iMac. As soon as Debian Bookworm is released as "stable", I will likely use rawtherapee some of the time as I used it when my camera was supported. If I had a Nikon camera, then I would use the free software that Nikon offers.

In DPP:

But if I go to the basic tab and move the input range to plus 2.0:

then it seems to me that I can see a histogram of the full range of data captured:

So far as I can understand, I have increased the dynamic range of the input data included and changed the shape of the gamma curve to compress that range into sRGB for display. Now none of the pixels have a red value of 255. But, the color space is distorted. It might still make an attractive photo of a red flower in sunlight.

Your mileage may vary.

Your 'S' shaped curve is quite similar to DR test curves over on the other site - going from illuminance from their test strip to sRGB.

The 'S' shaped curve does reduce contrast** at low and high illuminances. One camera I had actually tested with a straight line at 50 ISO going up to 255 sRGB (see above). Good for clouds, eh?

** contrast in this context being the slope of the transfer curve.

I have heard the S shape described as toe and shoulder. It seems to me a good default most of the time.

Instead of contrast, I usually think of it as the spacing of the mapped values. Quantization.

not playing silly games. Thats Dunnos expertise.

🤐

True on many levels. Consider Hunt's taxonomy for color reproduction:

Spectral color reproduction, in which the reproduction, on a pixel-by-pixel basis, contains the same spectral power distributions or reflectance spectra as the original.
Exact color reproduction, in which the reproduction has the same chromaticities and luminances as those of the original.
Colorimetric color reproduction, in which the reproduced image has the same chromaticities as the original, and luminances proportional to those of the original.
Equivalent color reproduction, in which the image values are corrected so that the image appears the same as the original, even though the reproduction is viewed in different conditions than was the original.
Corresponding color reproduction, in which the constraints of equivalent color reproduction are relaxed to allow differing absolute illumination levels between the original and the reproduction; the criterion becomes that the reproduction looks the same as the original would have had it been illuminated at the absolute level at which the reproduction is viewed.
Preferred color reproduction, in which reproduced colors differ from the original colors in order to give a more pleasing result.

You could argue that all we can do with today's commercial system is the last one.

I have noticed that the default processing in Lightroom has a very marked shoulder at the top of the curve. About 3ev of highlights is compressed down into 1ev.

Here is an image with default processing in LR:

And here is the same image with the shoulder more-or-less straightened out (Exposure = -3.0, Whites = +40). There is a lot more contrast and detail in the highlights, but the mid-tones and shadows have been made much darker.

In high contrast situations, I like to use a linear profile to get rid of the shoulder at the top.

Proper exposure is the one you're happy with. Chances are, someone else would choose something different. But as long as the person taking the photo is happy with it, that's all that matters. You can't please all the people all the time, so best just please yourself.