The Sennheiser MKH405 is a unique shot gun condenser microphone that can be used for a variety of applications.  While it can be used for recording during filming, I've only used this in a recording studio for recording music.  However, I do think that it can be used in pretty much any situation where you would want a lot of detail in your sound.  The mic can be powered by AAA batteries if you want to use it on the go.

OVERALL OPINION

Overall, the Sennheiser MKH405 is very impressive mic.  While I have been told that this mic is best suited for recording audio during filming, I have had success using it in the recording studio.  It is great for a variety of purposes, but probably is suited best for recording acoustic instruments like piano and guitar.  I have also enjoyed using it for vocals or as a drum overhead, I think in the right situation it is well suited for both of these.  I haven't seen these in too many different studios, but I was glad I tried it out because it is a really cool sounding microphone.  It is definitely on the obscure side of Sennheiser microphones and isn't generally considered a go to studio microphone, but it has certain qualities of it that I find work very well for the applications that I mentioned earlier.  I don't know too much about the price or the availability of the MKH405, but I would imagine that they aren't the most readily available mics since they are no longer made and I haven't seen too many of them around at all.  Having said that, I would definitely recommend checking out this mic as I think most recording engineers would enjoy using it as I've found to have a good amount of success with it in the times that I have been able to use it...