Russ - I know who HC-B is - you don't need to go down the slippery slope of personal slights to make your point.
Rob & Eric, I couldn't agree with you more, about working to fill the format first. I do the same for about most of my work. But I think the difference between my outlook and that of Russ is that he sees aspect ratio for the format you are using as an absolute, I don't. Nor do I see cropping from the original aspect ratio as "correction device". It is not a "failure of [the] original vision" if you choose to crop a scene differently from the camera's aspect ratio. That's absurd.
The moment we create absolutes is the moment we close our mind to other possibilities.
The whole point about the different formats all capturing a well-composed image should tell you that just because you have one format, does't mean you have to be restricted by that format! If I'm shooting with a 6x7 and I see the scene in front of me as a square or 16:9 (or 16:10 or 16:
then I shoot it knowing I need to crop later because I can't crop in the camera. The format I'm shooting is very helpful for composition most of the time, but not always.
Do you follow the rule of thirds as an absolute? No, you use it as a guide to composition. It's not a failure if you choose to deviate from it! How often are we reminded that there are times to "break the rules of composition"? Perhaps not often enough!
Do you accept all images directly out of the camera as "finished" or do you post-process your images as a "corrective device" for your "failure of your original vision". No, you don't do either. You realise a camera is only a machine and that you must then work to bring that machine image (the negative or raw file) back to what you, as an artist, visualized in the field. You might "burn and dodge", add some exposure, change the contrast, etc. Some people view these as "corrective devices" but they're not. They are an integral part of the art of photography. Cropping is part of that art - not necessarily for every image, but certainly for some.
Cropping is not a "failure", it's thinking outside the rectangle.
For most of the images I choose to crop, I do so because
that's the way I saw it in the field. I made the exposure knowing that the scene before me doesn't fit the format I'm using. As I said previously, I'm not going to ignore a scene I visualise as a square format just because I'm carrying a rectangle! I shoot it with my rectangle and crop to what I originally saw - a square.
We have spent too many decades living with the legacy of small formats and grainy film - that's where this notion of not cropping arose - to preserve image quality in a time when grainy 35mm was still competing with medium and large format. No artist should be hemmed in by the limitations of technological design. It's a rather anthropocentric view that a narrow selection of human-made rectangles should command the way the world is seen. We can certainly use those rectangles to assist our visualizing process, but they need not be absolutes. I understand the concept behind the golden ratio, but even Oskar Barnack got it wrong with a 3:2 format - the golden ratio is 1:1.618...
We've been imposing human constructs on nature for far too long. Isn't it time to liberate ourselves from this myth that humans can control nature? The pursuit of artistic expression is far too free an endeavour to be restricted by rectangles designed by engineers. The bottom line here is that composition need not be limited by specific aspect ratios.
I know you will disagree, but as I said in the beginning, we should agree to disagree. While I don't agree with your point-of-view I understand the thinking behind it. Even if you don't agree with my point-of-view, I hope you understand where I'm coming from.