My friend is using a shure sm58 on a boom to record dialog on his short films and he said it works suprisingly well. has anyone else tried this microphone?

The SM 58 is a very good dynamic microphone, I use it almost every day in my recording studio. But, as good as it is, it is used primarily for vocals or as an interview mic - not as a shotgun/boom mic.

First off - the SM 58 has a standard cardioid pattern, and not a super cardioid pattern such as a traditional shotgun - thus you will probably pick up a lot more outside noise with this microphone than you would with a shotgun (such as the Audio Technica 4071A).

Also - because it is a dynamic microphone, you won't get the sensitivity and the crispness of a condenser microphone (as most shotguns are).

And also because it is a vocal mic - and not designed for shotgun use - I'm sure you won't get the range of a traditional mic either.

But with all that said - a SM58 is a nice mic to have in your kit - and is a lot cheaper than a traditional shotgun microphone. Also - it can take a TON of abuse and keep on working fine.

And if it suits your needs as a boom mic as well out in the field - then I see no harm in using it - though you might get better results and better sound quality with a shotgun.

Hope that helps
Ryan