Autoexposure bracketing

The X100 offers a fairly-standard Autoexposure Bracketing option, which makes three exposures at +/- 0.3, 0.7 or 1 EV intervals in rapid succession with a single press of the shutter. It's accessed as a drive mode, which means it can be combined with the self-timer function, which is useful when working with a tripod. Our only criticism is that the 1EV maximum interval is distinctly restrictive for High Dynamic Range work (which for many users these days is the major use of AEB).

ISO bracketing

The ISO Bracketing mode takes a single exposure and develops it to JPEGs of three different brightnesses, up to +/-1 EV. It won't save a raw file regardless of your settings - if you have the camera set to record raw, turning on ISO bracketing will override it without warning you, and save three JPEGs instead.

0 EV version (ISO 200) 100% crop - highlight detail
+0.7 EV version (ISO 125) 100% crop
-0.7 EV version (ISO 320) 100% crop

We can't see any obvious reason to choose this over autoexposure bracketing, which gives a superficially similar result. Indeed there are very good reasons not to - the fact that all three files are generated from a single raw capture means that the darker version won't contain any additional highlight detail, unlike with autobracketing. It's also worth bearing in mind that if you shoot raw, the in-camera processing lets you change image brightness freely after the event anyway.

Film Simulation bracketing

This takes a single exposure and develops it to three JPEGs in the Provia, Velvia and Astia modes, again discarding the RAW data afterwards. This is quite a nice quick way to compare colour modes and see which you prefer, but once again if you shoot RAW you can do this at your leisure later (and experiment with tone curve tweaks and B&W too).

Standard (Provia)
Vivid (Velvia)
Soft (Astia)

Dynamic Range bracketing

This mode takes shots at the camera's three DR settings (100%, 200%, 400%), using three exposures made from a single press of the shutter button. This may sound like a perfectly sensible idea, but strangely it doesn't do what you might expect and shoot them all at the lowest possible sensitivity for each DR setting. Instead it makes all three exposures at the same ISO, meaning 800 in bright sunlight when it could easily use 200 instead.

DR 100, ISO 800
DR200, ISO 800
DR400, ISO 800
100% crops, highlight detail

On one level this works exactly as advertised: it's an easy way of ensuring you that capture all of the available highlight detail, which in the example above demands DR400. But we can't help feel it's not as well-implemented as it could be; sure you can choose a version of the shot with the optimum DR setting, but if that turns out to be 100% anyway, the overall image quality would have been better if it had been shot at ISO 200 (and the whole point of bracketing is as a shortcut to getting the best image). It also has the same Achilles Heel as the ISO and Film Simulation bracketing modes, as it won't save RAW files either.