Sunday, April 26, 2009

Bike Camera Project

During this year's Bicycle Tour of Colorado I want to capture some of the spectacular scenery and downhill runs on video.

I considered both helmet and bike mounted cameras. Both have their advantages. The helmet camera is obviously has the advantage of inherent vibration dampening and tracking the riders point of view. However the helmet cams I can afford lack the flexibility of also serving as a high quality still camera and take only a limited amount of SD memory.

On the other hand there are plenty of 8-plus megapixel relatively inexpensive cameras out there that can also do fairly good video, however I don't think I want them hanging off my helmet.

My worry about the bicycle mounted camera is first finding a secure method of mounting the camera to the bike that won't interfere with normal operation and can be removed easily when not in use. There are several DIY bicycle camera mounts possible but I was unimpressed with all of them. Luckily I found one off the shelf at my local REI store that is near perfect. The Pedco UltraClamp Camera Mount ($24, http://www.rei.com/product/777251 ) attaches to the stem of my bike with just a twist of its set-screw and fits as if it were made specifically for this purpose. The mount also has three points of adjustment that make alignment of the camera simple and quick. This is problem solved, it was on to the second concern.



A bike mounted camera will need to cope with some road vibration that may cause blurred video and possibly even damage to the camera itself. To address the blurred video concern I decided on a test using the Pedco UltraClamp Camera Mount and cheap Casio Exilim 7.2 megapixel camera I already own with a 512 SD card doing 640 x 480 30 fps video. I selected a rough stretch of road that is fast with few stops and some small hills as the perfect test track for vibration. The following video starts on a fairly smooth bit of road for reference prior to turning right on to the test road.

video

Viewing the video you can see that even at 20+ mph on the test road vibration doesn't impact the image quality significantly . A reminder here the video is desgraded in conversion process of uploading to this blog. Now the the 512MB of SD memory provided under 7 minutes of video recording, which is another concern I will discuss later. After about 20 miles on the bike the camera mount remained secure, but there was a minor problem. The camera wanted to twist counter-clockwise on the camera mount in response to road vibration. Basically, it was trying to unscrew itself. I think I can address this either by brute force tighten of the mount screw or perhaps using something like Locktite Blue on the threads. If not then I will need to place a vertical pin on the mount pad to physically stop the camera from turning.

With video quality assured then it was a matter of selecting a camera rugged enough to handle the vibration and unpredictable weather of Colorado. After looking at many-many cameras I decided on the Pentax W60 which is small, rugged, waterproof, and feature packed. The best news is that at the same video resolution and frame rate I used in the initial test, I will have over 6 hours of continuous video with a 32GB SDHC card! While I am not certain how long the camera battery will last, this can be fixed by purchasing an extra battery, if needed. I have the Pentax W60 on order and I will provide a project update after I take it for a test run.

There are a couple of remaining issues that I need to address. When I did the BTC for the first time I decided to camp-out. This worked out fine, except that access to A/C outlets was just about non-existent, so charging devices like cell phones and cameras was impossible. The other issue is how to off the 32 GB SDHC card over the 7 day trip.

The good news is that I may have the charging problem solved with use of a light weight folding solar array that provides 12DC at with sufficient current to charge the Pentax W60's battery(s). I will provide a project update after doing more research. The storage problem is an issue since my Netbook only has 16 GB of solid state hard disk in it, so I clearly need some other mass storage device. Of course I could fix that problem by brute force with 7 32 GB memory cards, but at about $90/card that is an expensive solution. My guess is that I am going to use a small USB powered external hard drive in conjunction with my netbook. More to follow!

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