Some rambling thoughts:

One reason why I stuck to crop sensor on Nikon (“DX” with a 1.5x crop factor, vs 1.6x on Canon) is that it offered me a choice of nice 24-XXXmm lenses intended for full-frame that would give me a good-for-people-photography focal length range on a crop sensor body. It also meant I got to use the usually-superior center portion of the lens, with any softness at the edges or in the corners getting cropped out.

F/1.8 prime lenses are a popular compromise, at least on Nikon. Giving up the difference between f/1.4 and f/1.8 allows for big savings in cost and weight. The great and expensive Nikon 85mm f/1.4 costs ~$1600. The good and very popular Nikon 85mm f/1.8 costs ~$500. The two primes I keep in my camera bag are a 35mm f/1.8 and a 50mm f/1.8.

The equivalent of 35mm on full frame would be 24mm on my Nikon. But I haven’t felt a need for that. 35mm on my Nikon – the equivalent of the classic “nifty fifty” 50mm on full frame – has suited me just fine, augmented by and actual 50mm that is equivalent to 75mm on my Nikon.

I’ve been sticking with f/8 in my sets with studio strobes, which would be more “deep focus” rather than “full focus” with my crop sensor. I probably should try experimenting with f/5.6 and maybe f/4. But I’ve been liking what I see with f/8 in my photos, so haven’t had much incentive to try anything different.

With my “walk-around” shots (e.g. at Fetcon) I’ve been using prime lenses at f/1.8 or f/2 because ambient light. This will often give me blurred backgrounds, which is good because the backgrounds are often cluttered.

So I’m confident I could do shallow-focus if I needed to, although not at the extreme of f/1.4 on a full frame camera. (And if I got serious about it, I’d want to rent or buy one or two expensive primes.) But I haven’t really felt much incentive to do so, except as a side effect of needing “moar light” when doing ambient-light photos indoors.