Raw histogram and why does it matter

Yes, I wouldn't get too gung-ho about declaring raws as non-images, either. Why reach for the binary definitions, when nuance does a much better job?

I like to think in terms of what happens when we stretch the parameters. For example, if a monitor had enough resolution or you stood far enough away from it, you could actually see the CFA pattern go extinct, whether your display is monochrome or color. So as far as CFA is concerned, it may only be an issue when we are magnifying the pattern too much, just like when we look at a printed image or a monitor screen under a microscope, and see dither patterns or separate little red, green, and blue rectangles; it is just a matter of degree. You could drop 2 out of 3 color channels just like a CFA in each pixel in a quality, realistic sRGB image, and if you step back far enough, the CFA pattern will disappear, and the image will simply seem a little too green and a bit too dark, but varying the brightness of pixels could get around that, and there are many monitors now that can give high pixel output, to compensate.

We could throw a convolution of

0.25 0.25 0.00
0.25 0.25 0.00
0.00 0.00 0.00

on your image, and the CFA effect vanishes, or just swap neighbor pixels randomly, and you get a noise dither instead of a CFA.

Perhaps it would be better to ask how realistic an "alleged" image is, than to ask if it is really an image.

More of what Sony and Nikon have written on the raw compression options they offer...

It's been a while now, so I don't remember the specific options I used, but I once took a variety of lossless Canon raws and converted them to uncompressed DNG, and then ran maximum lossless compression on them as available in 7Zip, and some of the 7Zip-compressed files were as small as 20% the size of the original Canon lossless compressed raw files. That's definitely superior to cRAW, but it is the time element that keeps such compression from being used by cameras; the cameras need to get things done fast, and don't have the time for maximum compression. Also, they take longer to decompress.

I don't remember who or when, but someone did in fact refer to non-ETTR as "under-exposure" in this thread. I know because I started to reply to it, but changed my mind. It should be called "X stops short of ETTR", I think; not "X stops of underexposure", as I think of "underexposure" as a phenomenon of missing the target nominal exposure of an ISO setting, as the default meaning. It is implicitly part of the exposure triangle paradigm, I think, which we can use or ignore.

I wouldn't declare "raws" as non-images, either. They are latent unprocessed images which become visible images when the raw capture data is processed in a manner which renders it in a viewable form.

Not restored, approximated.

That's funny.

LOL

For certain lossy compressed formats white balance is applied to the data.

You appear to have quoted what Nikon has written regarding their NEF raw file format in two different ways. The first is to quote a string of sentences which appear to support your viewpoint. The second chops out words from sentences with little to no recognizable connection to their context. You might consider using longer quotes with meaningful context in the second instance.

Not my viewpoint.
And "more ideal" is simply nonsense. Ideal is an absolute and therefore cannot be compared.

Whose is it then?

The phrase more ideal suggests something which is closer to an ideal. You can find several varied examples of the use of "more ideal" here.

I can find a lot of nonsense, like exposure triangle. Not interested.

The viewpoint that lossy is pseudo-raw and not raw isn't just my viewpoint, it's a simple fact. Lossy isn't raw neither by Sony, nor by Nikon technical definitions.
Nothing further. Ciao.

I'm glad you're clear that they are indeed images. Now let's work on viewable. The raw image data in a raw file (as opposed to the JPEG preview image) is stored in a single plane. That makes it a monochromatic image. If can be viewed in the same way as any monochromatic image, ignoring compression if present. It may not look like what you want it to look like (it has a gamma of unity and is not demosaiced), but you can't say it's not a visible image. It is no more latent than any monochromatic TIFF file.

Sorta, kinda like "very unique."
😏

Rich

I neither understand your optimal exposure definition nor your maximum exposure definition. Neither was either has to do with dof and motion blur.

Agreed, but it can't hurt to understand how to maximise image quality - doesn't "good enough" really equate to just optimising image quality.

Editor/camera histograms vs. RAW histograms

The two SOOC jpegs examples below were shot the same except for the dynamic range setting (Fuji X-T2) - DR200 (basically off) on the left, and DR400 (2 stops of dynamic range "enhancement") on the right with their corresponding histograms in Lightroom directly below them...

Flatter highlights in the DR400 example (R), but similar histograms.

Below are the corresponding RAW histograms (via RawDigger). As can be seen here, the DR400 RAW histogram (R) is 2 stops darker (further to the left), in this case indicating 2 stops less exposure (due to the DR mode requiring a higher ISO setting and, relative to the first example at base ISO, a 2 stop reduction in sensor exposure.

So why isn't the image 2 stops darker in Lightroom too? Because the camera's jpeg processing has compensated for the reduced exposure used by the DR mode automatically, and Lightroom will similarly read a metadata tag in the RAW file telling it to also compensate by moving an, invisible to you, "exposure" slider 2 stops to the right before you ever see anything, producing an initial image of similar brightness to the example with "normal" exposure..A RAW histogram used in this way is a great way to understand what's actually going on "under the hood".

But what does that mean in the real world? Well, in this case it shows that while the resulting images look similar at first glance, there is a price to pay for a sub-optimal exposure, pretty easily seen here upon closer inspection...

DR400 is not two stops less exposure. DR400 keeps the set exposure (shutter speed and aperture) and lowers ISO by two stops (hidden). That is why the lowest possible ISO at DR400 is two stops above the base ISO. When the camera converts the raw to JPEG, it boosts the shadows and midtones (by two stops) while keeping the highlights intact.

Adobe reads embedded DR mode data to lift the brightness of shadows and midtones while keeping the highlights intact.

BTW, the DR modes are mostly useful for JPEGs.