HDR is a much maligned and often over used process, mainly used for colour photography.
I find it a very effective tool that extends your exposure limits, after all HDR stands for High Dynamic Range.
My go to camera, that due to it’s size, is with me all the time is a micro 4/3 Olympus.With a 20mm pancake Lumix lens, it’s not as compact as an iPhone ,but much more versatile. It’s about the same weight as a medium format lens.The only person complaining about me using it ,is the Chiropractor.
The smaller sensors , in these cameras, benefit greatly from HDR, gaining a wider range of light gathering. The smaller file sizes also speeds up the processing of up to 7 exposures when required.
On that note, most times you can get away with 3 exposures and most DSLRs can bracket this amount. The General rule of thumb is – The greater the light to dark variation the more the exposures required.
For example, a still life of a rose, would only need two or three exposures. A Valley at Sunrise may require up to seven.
This particular image looked a bit overdone in colour, but the HDR has done their magic with the Tonal Range.
This image went from Lightroom with no development or presets straight into Photomatix Pro .The processed file is 91MB TIFF