The truth is that today’s digital cameras offer superb quality, and what one chooses to shoot is a decision that often reflects personal likes and dislikes as much as anything else (see Is it the equipment?). But equipment, especially lenses, can make a real difference to the “end game”, and here is a real-world example—
The March 2008 National Geographic has an article on Iceland: Power Struggle — The People of Iceland Awaken to a Stark Choice: Exploit a Wealth of Clean Energy or Keep Their Landscape Pristine. Iceland is a place I’m looking forwarding to visiting someday, with its dramatic landscapes.
There is one panoramic image that drew my attention (“Molten lava flowing across wetlands and into the cold waters of Lake Myvatn...”) . The image is a fold-out of about approximately 19" X 10". My first impression was “wow—what a stunning landscape!”. My next impression was that the image sharpness is disappointing; excepting the center of the image, both left and right sides are visibly blurred, even at the relatively modest 19" X 10" size. My educated guess is that the edge blurriness is due to poor lens performance—a probable example of equipment (lens) impeding the final quality in spite of photographer skill.
So what is “good enough”? In this case, the image unequivocally succeeds in depicting the stunning beauty of the landscape. It is well composed, and few readers will note the sharpness issue. So it is good enough.
Yet if this were my image, I’d be very disappointed with the obvious blur; even in the smallish 19" X 10" reproduction the shortcoming is visible. It is certainly not up to my standards for a fine-art print, and I suspect that would be the conclusion of many landscape photographers. A 30" or 40" wide print would show obvious problems, meaning that the image would be of less value for sale or exhibition—possibly not even viable at larger sizes—a serious concern for fine-art landscape photographers.
In short, here we have a case where equipment choice did matter—a lens capable of edge-to-edge sharpness would have produced an image with much more potential for sales and exhibition. Regardless of the lens, the same amount of effort is involved in making images, so choosing lenses that render images with top quality is preferable, and why I shoot the Zeiss ZF Lenses on a regular basis.