I can tell you from personal experience that a shotgun mic mounted on top of your camera provides excellent results for your on-the-fly interviews if you 1) use a wide angle lens (about 35mm), and 2) do not have any loud noises going on behind the person you are interviewing. What does the lens have to do with anything, you ask? Well, if you are doing a head and shoulders framing of the subject (with a little off-centeredness, of course, for compositional effect) then you will find that framing of that sort will bring you within a perfect distance to pick up the high-quality sound from your interviewee. In my experience, the results are as good as booming the mic from above.
I am a run-n-gunner, so I try to use the smallest equipment I can with the easiest techniques for capturing high-quality audio. Booming from above is usually out of the question for my purposes.
One more thing, just in case you want to know: I use a Rode NTG-2, powered by a Juiced Link pre-amp. Dang is that combo excellent!
Anyway, hope this helps. Try it, and you won't be disappointed! Have fun!
P.S. Let me know if you want to see an example of the results of this technique. I'll send you a link to a vimeo I did, which in itself is pretty boring sh_t if you are not a laboratory professional, but it shows how I utilized the on-camera mic for great results.
A great movie to watch for the visuals and audience involvement by that wide angle, close-up filming! But, to be a bit of a party pooper, I think it was a little far-fetched in realistically portraying what a person can survive. Forget the hypothermia, Glass would have been dead halfway through that magnificent bear-mauling scene (a scene that is a reason in itself to see the movie!). They must not have showed the parts where he gets transfused a few liters of blood and saline afterwards so that he can have the strength to crawl out of the hole :)
Thanks for all your good advice.
I have both the Sanken COS11-D and the Oscar Sound Tech 802 lav. What I find is that the OST gives less than half the signal of the Sanken. For instance, if the Sanken is reaching around 12 dB, the OST with the same settings will be reaching below 6 dB on average.
Do you also find this to be true? Does it bother you?
By the way, I'm using both lavs directly into my Sony PCM-M10. I do have the Sennheiser system, but found the separate audio recorder set-up is way more convenient. The Sanken COS-11D works very well in this arrangement.
I've thought long and hard about the same question you ask. I decided in the end I would buy glass specifically for the BMPCC. Trying to get lenses that would go well with both the BMPCC and your Canon camera is, in my opinion, making too much of a compromise one way or the other. The speedbooster is almost the price of a lens, first of all. Second, any time you use the speedbooster, it's going to suck the battery life out of the BMPCC even more than the already atrociously short battery life. Finally, if you want a normal to wide angle look on your BMPCC, it will most likely leave you with a very wide angle look on your Canon (something you might not use a heck of a whole lot in your video productions).
Now, if you don't care about battery life because you have an external power source, then my points about the speedbooster are moot. In that case, you're not like me in that you don't mind increasing the small form factor of the BMPCC.
If you don't mind shooting VERY wide on your Canon so that you can have a normal to wide on your BMPCC, or if you don't mind not being able to shoot wide on your BMPCC so that you can use your Canon at less wide to normal angles, then my points about compromising one or the other are also moot. I guess in this case it would depend on what camera you want to shoot with more.
Since I prefer shooting with my BMPCC, then I favor buying very wide micro four thirds lenses for it. If I preferred to shoot with my Canon (5DMIII), then I would get a speedbooster and buy lenses primarily for the Canon and use the speedbooster to allow me to use them with the BMPCC.
In the end, it's up to you and how you do most of your shooting. But for me, since I love my BMPCC, I'll buy lenses specifically for it (wide micro four thirds glass) so that I can keep the form factor small (no large lenses and not so much need for external battery supply) and have wide angles of view.
Remember, the crop factor (!) is 2.88 from full frame to BMPCC. A 15 mm lens on the Canon will give you an equivalent field of view of 43 mm on the BMPCC (without a speedbooster). Using a 15mm on your Canon may be a little too wide for most purposes if you're filming with it.
Anyway, my opinions aside, happy shooting!
I was referring to MFT lenses that are good "wides" for the BMPCC. Specifically, I was talking about lenses that are anywhere from 12mm down to 6mm, which gives you a field of view of about 35mm and 18, respectively. I myself have the 12mm lens made by Kowa. For some reason these Kowa lenses are not well known here in the States. I had to order mine from Japan (through ebay).
Do you have any experience with these, or other good manual lenses that are considered wide on the BMPCC?
Perhaps the placement of the mic is not the greatest? Maybe the room has too many reflective surfaces? Maybe both? In my experience, a mic that is not the highest quality, but which his placed close to the talent in the proper position (aimed at his mouth area) and not surrounded by reflective surfaces, should be able to give you results above that of "home video" sound. Please let us know your set up.