Photographer & Videographer based in London, UK.
re: mics. I use a Rode NTG2 shotgun mic ($200ish) recording (XLR balanced) into a Zoom H4N. Great little budget setup especially for on location work. Problem with any digital recorder with no XLR input is that the signals going in are generally unbalanced, that's why it's easier to pick up radio & electromagnetic signals nearby. I also use a Rode Smartlav with an iPhone/iPad, handy but quite hissy (the smartlav+ is better), so hard to get that crisp, present sound. I use the 'de-hiss' processing on the rode rec app and add some top-end eq/compression in post and mix with shotgun mic audio for more more body/ambience if needed.
The latest version of Adobe Audition CC has a great restoration tools and spectral noise removal system for getting rid of mic pops, tone hums, knocks & other background noises - I find it's less fiddly than Izotope RX4's spectral noise remover - but its has to be said RX4's noise reduction system is fantastic.