Whenever you use external microphone , headset must use to monitor and listen to the sound it is distorted , noisy , or plug failing. Beware of cheap LED because they light at an angle of 30 degrees , which is very close. If the interviewee move , you need to adjust the direction of the light. Oth problem with cheap LED is the "color rendering index" IRC is pretty poor, mostly missing the wavelength red, and green has in excess. It is very easy to recognize an LED bad : He has hundreds of units , only illuminates in a closed angle and has greenish or bluish . Each LED has a bad individual power of only 0.1 watt. The LED iluminadore good low volume use as each LED unit has up to 5 watts (50 times stronger), then do not use hundreds , only 9 or 12 units, which are good "short" like a drop which rests on a smooth surface, and they use 12 volt battery. See this site , and can find something similar in your country.