Any jerk can take a picture, as I suspect that gentleman was trying to tell me. The real skill comes later, in the darkroom, or on the computer, when that latent image is processed and enhanced.

I've played with, and studied formally, film photography. But I've also worked professionally with digital image processing, and both are essentially the same thing. The big difference is that what you do digitally can be described mathematically. You can precisely communicate what you do on a sheet of paper, with words and equations. What happened in the darkroom was so good because people did it for over a century and craftsmen developed a seat-of-the-pants instinct for it.

Digital image enhancement and processing hasn't been around as many years, but you don't need to wait for a latent image to develop to see the results of an experiment. And you can tell someone else what you did over the telephone. You see it immediately and you can try something different. Digital vs film is like modern metallurgy vs traditional Japanese swordsmithing. The former is theoretically better, but the latter has a lot more subconscious mind and human experience incorporated into it.

Some examples. There is a photographic technique called "dodging". It is a form of differential contrast stretch done digitally by examining each pixel and mathematically diminishing its value if it exceeds a certain amount, and increasing it if it fails to reach a certain value. Or you can use a more sophisticated algorithm that doesn't use cut-off values, but the results of a continuous mathematical function.

In the darkroom you do this by throwing the negative in the enlarger, and burning it onto the positive paper, all the while walking around it with a fly swatter
and by casting shadows, diminishing the light that gets to the brighter parts of the image, and allowing the light to pile up on the fainter parts.

This technique allows you to enhance faint detail while simultaneously subduing bright areas, great for showing structure in images with great dynamic range, with both under- and over-exposed portions, like faint nebulae with bright central nuclei.

A related technique is called "unsharp masking". In the darkroom, you make a deliberately out-of-focus transparency out of a negative. You then develop it, and throw it on top of the positive paper on the enlarger, and create a positive print using the original negative in sharp focus and the transparency to cast a shadow on the print stock. The areas with lots of detail are enhanced while the areas that are flatter and unclutttered are untouched.

Digitally, you create an average or median image from your original image (you replace each pixel with the average or median of the surrounding pixels in an n x n box around it). You then subtract the "blurred" average/median image from the original and brighten the result.

In either case, the effect is to enhance the edges and transitions and to give the illusion the image is sharper.

In either analog or digital image enhancement, you are not creating new data, you are just altering the statistical information distribution of the data so you can avoid the limitations, and take advantage of the strengths, of the human visual system.

Do you remember those first images of Io that looked like a pizza? The same imagery was processed later using a Saturation-Hue-Intensity Transform that gave a much better look at subtle gradations of color as well as an esthetically much more attractive and informative image. I developed software to do that back in the early 80s, and I recognized the finished product immediately when I saw it applied to the Jovian moon by NASA.

My boss at an oil company showed me an article mathematically describing that process and asked me to code it up and apply it to some of our data. I called the resulting Fortran algorithm SHITRAN, and it eventually wound up in the Contributed Library maintained by our software vendor. I've always wondered if it was my code that brought out Io's inner beauty, or if some anoymous geek at JPL discovered it independently.