Originally posted by DaveHolmes Sorry should have added that he was having trouble creating oof/bokeh'd backgrounds
Long focal lengths allow you to throw the background out of focus at a smaller aperture.
E.g., 50mm at f2 = 77 at f2.8 (or something like that).
Therefore, if the 50mm is a little soft at f2, the FA 77 will appear to have better subject isolation than the 50mm.
Or something like that. I personally find the 77 too long unless I am in a studio or outdoors, and prefer the flexibility afforded by a 50mm or 55mm on a crop sensor.
No quantum mechanics required
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