Once upon a time, photographers used this material called "film." It was a sort of chemically-coated stuff that was sensitive to light. You put it in a camera, much like our modern cameras, except that instead of reading back the picture files, you exposed the film stuff to light, and then "developed" it by submerging it in more chemicals which caused pictures to appear on it. No one's sure how: we think it may have been the work of pixies.

But in any event, this "film" thing came in a huge variety of sizes, sensitivities, color balances, and so forth. One interesting thing about it was that the chemicals on the film were particulate: they were made of little grains of stuff. (Possibly "pixie dust.") The bigger the grains, the more sensitive the film was to light (because it was more likely that a photon would hit a larger grain than a smaller one) but when the pixies developed the picture, the larger "grains" were more distinct than smaller ones and caused a certain amount of what we now call "noise."

"Aha!" you may be thinking. "This sounds sort of like what happens when I use the 'ISO Equivalence' setting on my camera!" Excellent thinking, and quite correct. Well done. In fact, our "ISO Equivalence" settings are derived from a comparison of the sensitivity of the sensor at a particular setting to the "ISO Number" of the film material. History may not repeat herself, but she often rhymes.

Now here is the thing, gentle reader, here is the thing:

Many of history's greatest photographs were created on this film stuff. And, because of the primitive nature of the chemistry involved, often the noise caused by the grain size was quite large and noticeable.

But nobody minded.

Or at least, not much. Because a good photograph is a good photograph and a great photograph is a treasure unto the ages. Yes, it would be nice if the picture was a little sharper and a little less noisy, in some ways. But in other ways, it gives an image character, definition, reality. And in other ways, it's just not important at all.

Now in our modern era with near-total control of almost unlimited amounts of light, digital signal processors, and other blessings of technology, everyone seems to expect every image to be sharp, noise-free, and perfect in all other ways.

This is foolishness.

Sometimes, it is just too dark, or the light available too uncertain. Sometimes, the subject is just moving too fast. We cannot change the laws of physics: the light available is the light available, the speed of the subject is the speed of the subject. Perhaps one day we will have interpolative technology that will turn our cameras into as much image generator as image recorder, but today is not that day. Nor, most likely, is tomorrow.

Do not bemoan image noise, dear friend. Do not dismiss a beautiful image because of mere grain. Consider it in context. Do you discard La Giocanda because her paint is cracked and flaked? Do you marvel the less at Stonehenge because cruel Time has strewn its mighty plinths like so many dominoes? No, at least, not if you have the soul of an artist, or any human sense of wonder.

So let us, by all means, make our images as well as it is possible to make them. But let us not demand the impossible, nor require perfection defined as sterile, plastic images with edges that could cut diamond. Consider each image in its own light, if you will, and judge it on its power to please the eye and engage the mind.

Thank you.

Hmmmm, interesting premise.  Grain and noise are not the same thing though.  Grain has a distinct pattern and one could actually control it by selecting a film appropriate to the vision of the artist.

Grain could be added by shooting the film at a different ISO than it was rated.  Pushing in the lab could have an effect.  The grain was a predictable thing.

The problem with noise is that it is not predictable, is often random and not consistent throughout the image and is generally beyond the control of the artist.  We know if we crank up the gain (ISO) we will get it, but we can't define with precision how it interacts with the shot.

I understand your comments and they are well taken.  To some degree, we control grain in post and add the artistic effect.

As time goes on, sensors will improve and noise will be less an issue for this discussion.  When I started shooting, we used Kodachrome 25 because of its low grain.  Today's ASA 400 films are probably equal to or better than the grain of that old Kodachrome 25.

There are times when you have to crank up the grain.  To that extent, noise may be something that we have to live with to get the shot, and the shot might justify the flaw.

However, as an old time film guy, grain was an artistic element of the shot and mastereing it was part of mastering the film.  I find noise to be a frustration, but not the end of the shot.