Re: FPS video rate question
- From: John Williamson <johnwilliamson@xxxxxxxxxxxxxx>
- Date: Sat, 23 May 2009 22:21:03 +0100
On May 23, 2:12 pm, John Williamson <johnwilliam...@xxxxxxxxxxxxxx>The trade-off comes down to bandwidth in the end. For a given sensor array and data transfer setup, which is what a camera basically is, the picture quality has to go down as the frame rate goes up. And no, you can't get out what you don't put in, even with YouTube, much as they'd like you to believe otherwise.
That camera (apart from stills) seems to offer a range from 30fps at HD,
to 1000fps at a much reduced quality of what I'd guess would be 112 x 64
pixels(The page says 224x64, but that's not a normal aspect ratio for
square pixels). File size per second of shooting time won't be much
different, and the video in the high speed case will be noisy and
equivalent to watching a very slow turning prop on your phone screen.
The intermediate speeds shown offer a trade off between picture quality
and apparent speed of motion.
Ohhhh, and here I thought I was doing good, getting more FPS would
give me better quality, when in reality it's the opposite? I take it
the video would be microscopic in size on my home computer and if I
was to upload it to You Tube, it would then get pixelated to fit the
You Tube player?? Would I not be able to view the 1000 fps video full
screen on my computer or will it get pixelated as I think it may? I
was hoping in addition to flying pics that I would be able to capture
lightning in high resolution at the 1000 fps??
The 210fps might be a reasonable compromise for YouTube, unless you need to know the instantaneous prop position to within a few degrees. (Are my calculations right? At 1800rpm, call it 30 revolutions per second, which is 7200 degrees, so 1000 frames per second is about 7 degrees per frame, I think) ICBA digging out a calculator at this time of night. Tyre deformation at landing speeds takes at least half a second to complete for most applications.
For lightning, just leave the shutter open in a still picture mode with the smallest aperture you've got and hope, that's how the professionals do it. The high speed moving lightning pictures you see on TV are usually artificial lightning superimposed on a background in the lab. At a thousand frames a second, you'd fill a gig of storage in well under a minute, even at DVD quality.
Another question would be pic in pic feature, would it behave if youThat depends entirely on the software package you're using.
have one video set for one resolution and the other another? I am
thinking ahead in that I would take landing pictures from inside the
plane and then have somebody "runway side" take the video from the
outside. I was thinking the 1000 fps for the outside pic. Would I
run into "timing issues" from the different record rates for each
Worst case is that you will need to render the high speed footage as normal speed footage, then do your picture in picture using the result. I believe some packages will let you mix frame rates in sources, but that's *way* above my level.
Bridge cameras will let you run in full auto mode and most of them have filter mounting facilities on the lens. They all have the standard tripod mount socket, too. I've got a clamp with a tripod screw on it which comes in very handy, as it's strong, light and rather firm on the grip side on both flat and round supports up to about an inch and a half. It'll hold a camera steady enough for usable video on a pedal cycle handlebar while you're off-roading it. I use a Fuji 5700 camera, which has a standard 46mm thread for filters, and very handy it is, too. Not quite as small as the one you've already bought, but pretty small for all that. For your fixed camera, use a preset, then all you need to do is push the shutter button, and as a lot of bridge cameras will record up to 2 hours of continuous video, it's push before brake release and forget for most pleasure flights. It'll stop automatically and gracefully when it either runs out of space or battery power. They will also run off an external supply, usually 5VDC, which can be obtained via a standard aviation 28V power socket and a commercial voltage reducer as sold to the truckers. Buy two matching cameras, and you don't have to think your way round two different control sets and capabilities.You'll probably end up with 2 reasonable quality bridge cameras or
camcorders, rather than compacts, as compacts don't let you use filters
to the same extent.
Yeah, camcorder would be the way to go, no question about it, but in
the tight confines of my plane and also in the interest of safety,
point and shoot will be most appropriate since I am the only one in
Somebody still needs to fly that plane :-)))George. ;-)
Tciao for Now!