Today I put together a video that compares the following microphones:
1. iPhone 5s onboard mic.
2. IK Multimedia iRig Mic HD.
3. Zoom IQ5.
4. Apogee MiC (96k).
5. iRig Pro
pre-amp with Sennheiser K6/ME64.
6. Yellowtec iXM with Beyer Dynamic hypercardioid TOTO head.
7. Nagra SD (green band stereo mic).
Part of this experiment is to determine the value of diminishing returns - should you spend £1000 on a dedicated portable recorder when an iOS and digital Lightning microphone that costs £100 might do the job adequately?
You'll notice I recorded at full gain where possible. This results in a possibly skewed subjective result - however it should serve to help you determine the sensitivity of each microphone solution relative to noise floor etc (although it's just a normal room in a house with the soundman's favourite the fridge-freezer about 20 feet to the right).
After reviewing the results myself it has cemented my opinion on my favourite(s).
The recording below has been through the mangle of iPhone AAC codec compression, FCPX render, and whatever Youtube decides to do with it, but nonetheless it will give you an idea of the character of each microphone.