While moving into my new place I unearthed a video camera that I bought 10 years ago or so. It's a Sony DCR-TRV250 and after charging the battery it still works! Yeah Sony! There are two really neat things about this camera (well three actually). The first thing is it has a great 20X optical zoom and a 700X digital zoom. The second thing is it has 'Night Vision' that lets you see stuff in low light conditions. The last thing that I didn't realize was neat until today was the I.Link as Sony calls it, in reality it's a IEEE 1394 Fire Wire interface. I didn't realize how cool the fire wire thing was until I tried to get the videos I made off the camera and onto my computer. More about that later. Anyway the first thing I thought of doing once I got this thing working was to use it to make some Schlieren videos.
If you have read my other posts and seen the videos that I was making with my FujiFilm FinePix camera (a great camera by the way) I was always having trouble getting zoomed in enough on my parabolic mirror to get a good image. That problem went away with the Sony camera and it's insane zoom system.
|Sony DCR-TRV250 In My Schlieren Setup|
The videos that I ended up making with this camera were more just to see if I could do it and not really all that experimental. After all everyone makes a video of a candle burning using Schlieren. One thing that I did decide to try that I hadn't done before was instead of using a razor edge or 'Schlieren Stop' was to try a Circular Polarizer instead. Above is a picture of what I ended up doing and below is a more detailed explanation.
I put the Sony camera on the linear slide that I was using to position my FujiFilm camera. You can see a picture of that HERE. The purpose of the slide is to allow the camera to be moved closer and farther from the mirror without it moving side to side and loosing the image frame. With everything zoomed in at the mirror 10 feet away it's easy to bump the camera and have it move off the shot.
Once I had it on the slide I put a Circular Polarizer in front of the lens. My thinking here is that the light if not refracted would make it to the camera OK and if refracted the light would be blocked. I'm not sure yet if thats what was happening but it worked. I'll play around with that a little later. The pin point light source was again the same LED that I was using before with the foil tape over it. Lastly I put a piece of red colored film over the LED to attenuate the light a bit. Without that the Sony was way overexposed. There is a exposure adjustment in the camera and I'll try adjusting that next time.
I did end up making a video or two with this setup and you can watch it below. As I mentioned there is nothing too special about the video, it's just me playing with a candle and trying some baking soda and vinegar experiments in a fish tank. The typical afternoon in the garage for me.
In a couple of places in the video I was using the 'Night Vision' setting and a couple of others I was shooting normal. The differences were interesting and I would like to play around with that some more.
The next challenge after making the video was getting it off of the camera and onto my computer. There are 4 video outputs from this camera, USB, FireWire, S Video and Composite. The first thing that I tried to do was use the USB video which required downloading a driver from Sony and installing it in Windows XP compatibility mode on my Vista laptop. I had to set the video camera settings to enable the USB and the video came right off and into a program called VLC Media Player. I chose USB because I have the cables even though the quality isn't all that great.
VLC Media Player is a free open source program that lets you play and convert video files as well as a bunch of other stuff. All I could do was get it to download and play the videos. I screwed around for 2 hours watching How To videos and reading the instructions and help files and never could get it to convert from it's native format to MPEG (or anything else). The native format seems to only be viewable by VLC and pretty much useless so I gave up on that nonsense. If anyone knows how to convert videos with the latest version of VLC please let me know with an email firstname.lastname@example.org or by leaving a comment. I would really appreciate it!
After becoming thoroughly frustrated with the USB I tried the FireWire and it worked great. I plugged the Sony into my computer, Windows found the driver and with Movie Maker Live I could control the camera from windows and get the video. Worked great!
The last thing that I did in the video was to put some baking soda and a candle in a fish tank in front of the mirror. I wanted to see if I could see the carbon dioxide when the baking soda was mixed with vinegar and the candle go out. I can see it in the video but it's not all that clear after the YouTube conversion.
All in all I think this was a success. The Sony camera works much better that the FujiFilm for Schlieren photography and this has given me some more ideas to try.
|Baking Soda and Vinegar Experiment|