Is there a lav mic I can plug into the camera that doesnt have phantom power. I tried to plug Sennheiser lav mic into my old Canon HV20 and it doesnt work. Its working only with the wireless system, but I dont need expensive wireless system when I am shooting seated interviews, so is there a solution for this? I mean solution for lav mics (I dont want to use shotgun mic etc.).

There are dynamic (magnetic) microphones which do not need phantom power.
But they are rather large, and very rare to find as a clip-on lav mic.

Virtually all modern lav mics are electret which DO require power of some kind.
The most convenient way is to use plug-in power from the camera.
But if your camera doesn't provide plug-in power, then you need a self-powered lav mic.

A relatively inexpensive self-powered lav mic is....
Amazon.com: Audio-Technica ATR-3350 Lavalier Omnidirectional Condenser Microphone: Musical Instruments (http://www.amazon.com/gp/product/B002HJ9PTO/)

Low cost lav mics such as the ultradisk 4016 do not need full phantom power at 48v and can work with 3-10v across the twin cable connectors. This is also known as plug in power and it is possible to build a very simple box to.provide such power as per the radio shack pzm mics from the 80's.

Search for ultradisk 4016 and you will hear examples of these mics that can be used direct with radio mics or with a power box like the one that akg make.

+1 on what Richard said. I have one of these for videos on my Nikon D7000, have also used it with a field mixer, quality and sensitivity are
pretty amazing considering the price. Just don't get the battery in backwards, it will still work but very badly, and some people have thought the mike was faulty because of this. And DON"T plug it into phantom power. Don't ask how I know this.

Thanks, I will probably try that Audio Technica lav.

A low cost dual lav solution for DSLR's etc would be to get one of these: http://www.akg.com/B29+L-779.html?pid=113

and two of these and off you go: http://www.uket.co.uk/ultradisk-4016-xlr-ta3f-mini-3-pin-pro-1-metre-3-5mm-unidirectional-lavalier-microphone

The AKG is around £50 and will provide mixing and power facilities for two mics, the 3.5mm jack output is also DSLR and smaller camera friendly but they also do version with XLR output: http://www.thomann.de/gb/akg_b29l.htm

This will give you a system ideal for interviews as you have two lav mics but you can still adjust the levels before you feed your camera and all for less than £100.

The Ulltradisk 4016 is a unidirectional lav mic which is subject to volume drop-outs from 'head turns', wind, cable noise, proximity and other unwanted abnormalities. An omnidirectional is usually preferable.. unless it is being used in conjunction with live sound system where feedback is an issue.

The Ulltradisk 4016 is a unidirectional lav mic which is subject to volume drop-outs from 'head turns', wind, cable noise, proximity and other unwanted abnormalities. An omnidirectional is usually preferable.. unless it is being used in conjunction with live sound system where feedback is an issue.

They say they are unidirectional but I have found them to work fine upside down and they are not very directional at all, here is a clip of two being used last week:
Ultradisk 4016 lav mic's in use - YouTube