| Author | Message | ||
     Greg_e |
A few boring clips from a quick ride today. I pulled one of the mounting bolts out of the oil cooler and put in a 1/4-20 stud. Then screwed a little Hama ball head to this stud and used the GoPro 1/4-20 mount. It's better but still not as rigid as I want and I'll probably have to buy another case so that I can modify it to make it more rigid. I also covered over the front push button because I think it whistles in the wind, seems to have worked since I don't detect any wind noise with the waterproof back at 70mph. This is different from every other test where no matter what back I used or how fast I was traveling, there was nothing but wind noise above about 50mph. I'm starting to narrow down the options to make it work the way I want. Also note that at certain engine RPMs the audio mutes, there is some kind of vibration that is causing the auto audio level to decrease the gain drastically. I need to work this out too. http://www.youtube.com/watch?v=oN1f3KFjAow http://www.youtube.com/watch?v=NmrI3ot1b2Q http://www.youtube.com/watch?v=7hTGjXggO2c | ||
| Ourdee |
It's picking up electrical noise from the bike. | ||
| Greg_e |
Why do you think it is electrical noise? | ||
| Ourdee |
Sounds just like some of my CBs when the engine is running, Pitch changes with the RPMs. | ||
| Greg_e |
I'm pretty sure that the sort of clicking noise is just an engine noise that happens to be at the natural frequency of the plastic case and transmits far stronger than the other frequencies. I was running the full water proof case, the same as what GoPro used in the formula car sample they have on their site. The same/similar clicking can be heard in that clip. What I did notice when I broke out the headphones to really listen is that at certain RPMs there is a very low frequency signal that is loud enough to fool with the AGC on the audio. I thought there was something in previous clips but never really identified it. It was way down somewhere below about 100hz and could really be cut off by a filter and nothing would be lost. I sent a support request with this info to them but I doubt anything will get done until the next hardware version of the camera. Later I'll strip the audio from those clips so I can look at the frequencies better just to make sure. Little steps to getting this to be what I want. I'll probably have to open it up and see if there is room for a small high pass filter on the back of the mic. The way I have it mounted this low frequency is probably coming in directly through the mount and case. I'll have to try the open back for the case the next time I get to ride, this probably won't be until April as winter is finally settling in to stay. | ||
| Iamarchangel |
I think the problem is basically the set-up is more sophisticated than you need. It's certainly one of the better cameras I've seen It has a brilliant high speed resolution that distracts by the backward moving tire illusion. There is also a terrific infinity focus on the camera which distracts through the brilliance of the fork tube. I suspect the mic is the same high quality, as are the internal AGC. I think it is keeping a peak value somewhere around the bike idle range. Notice how clear that sounds, it's everything above that that gets filtered. Most sound equipment have a filter at a specific point around the 100hz range. I suspect it is exactly the 100, maybe 60, I can't remember and my notes are not here. It has to do with countering sub-sonic feedback. Again, my notes are not here. | ||
| Livers |
Hey, was that my dentist's office?  Different perspective down by the cooler. Took me a bit to figure out your route. Let me know when you post a Locke to Genoa run. | ||
| Greg_e |
Since you probably have the same amount of snow that I do, it will be some amount of time before I get my bike out again. That ride was pretty much entirely to play with the camera. I didn't feel like checking traction on the roads to see what the limit was, so it wasn't a lot of fun. The mounting is getting closer, but I'm not sure if I like the oil cooler area, too much front tire. It might be a cool shot on the track to use as a cutaway from a camera mounted up higher but I don't think it is the best place for a single camera cycle. That said if I was racing I would probably have a camera down low for a speed shot (would look good in left hand corners), something up high for a regular shot, and at least one more installed where the brake light went to see what is happening behind me. A smaller standard definition camera pointed at the gauges would be cool for a picture in a picture, and one tucked into the helmet would make for some cool cutaways too. |
