If you understand the why behind these rules, they’re still helpful, I think. Slides have (had?) a very limited contrast range. If you got the exposure for the darkest parts of the image right, the brightest parts might have no image on them whatsoever—your transparency would be literally transparent! OTOH, negatives have/had a greater contrast range, and unless your image had a huge contrast range, you could just burn in the highlights in the darkroom. And if you decided to take the leap into the Zone System (Yikes!), the contrast of the final print was—pardon the expression—your bitch. You’d need a spot meter (unless your name was Ansel Adams and you could judge the contrast and do the math in your head) and a view camera, but once you knew the contrast range of the image, you’d decide where the tonalities would fall, and expose and develop accordingly….

Sorry for the trip down memory lane. It’s a round-about way of explaining why if I fell asleep back in the film age, and, like Rip Van Winkle, slept for years, only waking up now and you showed me your landscape, I’d say, “Oh, he must have shot that with a chrome film,” because you exposed for the highlights, in this case, the sky, and let the shadows fall where they may.

One great thing about digital is that we don’t have to reload with different films to get a chrome image (narrow contrast, dramatic differences between light and dark) or a negative image (detail down deep into the shadows)—we just have to know how to expose, and that in many cases, there is no one correct exposure, but different ones that lead to different images with differing impact.