On digital, 720nm and 830nm usually look more similar than many people expect. Both can give dark skies and bright foliage; 830nm tends to push the result a bit further toward pure B&W IR, with slightly stronger Wood effect, a little better haze cutting, and somewhat darker shadows. But the difference is generally modest rather than dramatic.

How much you actually see depends on three things: your sensor’s sensitivity beyond 720nm, whether the lens transmits those wavelengths well, and the scene itself. If the camera sensor has limited response between 720–830nm, the visual difference may be small.

For hotspots, they are mainly lens-related. An internal IR conversion does not guarantee they disappear. Longer wavelengths are often less foolproof, with somewhat greater hotspot risk than shorter IR wavelengths.

So, if you want maximum flexibility, 720nm is usually the safer choice. If you specifically want deeper IR for monochrome and don’t care about color possibilities, 830nm can give slightly stronger IR character—but expect an incremental change, not a radically different look.