Raw Histogram??

Danno, I hope the above was intended for the benefit of Beginners. If not, telling me how metering works is quite insulting

Equally insulting and will you PLEASE stop telling us your definition of 'exposure' ... grump.

Yes, the 18% number is the "traditional" number that was bandied around and I saw when I first got into photography ~17 years ago.

Over the last year or so on dpreview I saw people use something like 12% or 15% from memory in their posts. Don't hold me to those numbers.

What would you suggest is a more appropriate percentage to quote if/when in the future the need for similar posts come up in discussions?

That's why I limit ISO when using M + ISO Auto.

About 12.5%, which is three stops down from full scale. But the key thing is that it can vary with camera model number (and, I suppose, with camera serial number, but that is going to be a smaller effect).

That's one of the very few cameras that are calibrated in raw close to the standard.

seriously Jim, i think you need to rework those tests.

Yes, at high ISOs histograms can be helpful but do not need to be accurate.

It was certainly not meant as an insult.

It was partly also related to your earlier comment:

"there is very little or no penalty when "underexposing" by keeping the ISO a few stops lower than the maximum possible while keeping the exposure unchanged."

which made no sense to me because I cannot see how you can underexpose while keeping the exposure unchanged.

I make no apologies at all for including the definition of "exposure" I use in my posts in the interests of transparency and clarity.

Too many beginners, and even some who should know better, confuse image lightness and exposure and incorrectly use them interchangeably as if they meant the same thing when they do not. Very often when I question them to clarify what they mean by "exposure" so that their posts will actually make sense, they either run away or come up with all sorts of wishy-washy descriptions because they do not really know what exposure actually is.

At least with my posts people will know exactly what I mean by "exposure" and "optimal exposure" so there is no misunderstanding. Now, whether they agree with me or not is a totally different matter 🙂

Jim is correct.

Funny that you should say that. because the exposure settings on that camera were always different than any other camera i owned. now i will compare it to my a74.

Ideally we want to know where is the clipping as some clipping is perfectly fine.

Ok, thank you for that 🙂

So in the future if I posted something like "....contemporary camera meters are calibrated to output ~12.5% grey image lightness....", would you be comfortable with that?

Because your definition of "underexpose" is different from the most common one (making image darker).

In a beginners environment imo it is even more important to use the correct terms to describe things. Using different meanings for a word depending on the context can only lead to confusion and misconceptions for beginners.

Sounds more cut and dried than it is. Maybe Iliah could give you a range.

I do not see how that helps in general situations. After setting you exposure manually and the metering system sets ISO below the limit, the metering system may have selected an ISO value that will cause clipping. Maybe always running with -2EC (applied on ISO only) could prevent most clipping, but setting max ISO can't.

Hopefully he can.

As a "Plan B" would you be comfortable with "....contemporary camera meters are calibrated to output a firmware set image lightness...."?

Maybe we should avoid using the term under- or overexposure and instead use darkening/brightening.