I bought a keychain camera from Hobby King. Very small and incredibly cheap. Only US$7.69. Obviously it does not include any memory card. So I also ordered 2G Micro SD for US$5.59. Is it good or bad? Anyway I do not care if it is not good for this price. As usual from Hobby King no manuals are provided with the cam. The manual and calendar setting program, etc. have to be downloaded from "FILES" tab of above site.
Positioning of the camera was not easy since captured video only could be seen off-line after connecting the camera to a PC. However I found a way to use the camera as a web-cam by searching in the net as follows:
Connect the camera to PC with USB extension cable.
Give a quick press to "Power Button".
Then the mode of camera changed from USB storage to web-cam.
Now you can see the picture sent from the camera real-time. There are software dedicate for web-cam, but Skype can be used to see the picture. Go to "Video Setting" and select "GENERAL-UVC" as web cam to see the picture from the camera. It makes camera positioning much easier. Following is a screen capture of my PC with the camera heading to the PC screen and bit tilted.
Above bracket does not have freedom of installation on the carriages. So I made another type that can be easily mounted on the double roof part of the carriages. The bracket was made form 1.5mm styrene sheet and styrene triangle bar and pieces of foam were attached.
The cam can be installed very easily as this. This can be installed at any location of the carriage roof. This position would be good to take movie with loco. If you want to take entire train, simply install it at the end of the train.
Position of the camera checked by connecting to a PC. The camera is fixed be Velcro and it may move by the weight of the USB cable. So accurate positioning is not quite possible, but it is much better than nothing.