Robert_Charlton - 12:08 am on Feb 22, 2010 (gmt 0)
Some rushed comments (with the caveats that these are hurried and I'm not a video-compression expert)....
Flash memory vs tape should have little to do with what format is recorded. There are professional DV cameras that record beautifully to flash memory (usually, though, to variants of the original mini-DV format). There is, in fact, a big push in professional camcorders toward more use of flash memory... in large part because of faster workflow.
I think with regard to the original question, the key here is camera price. It is a marketing issue. Flash memory is where manufacturers want to go, and compromises in small, low-end, flash memory cameras for the consumer market are thus driven by chip capacity and price.
It's important to note that MPEG constrains how you compress, but not how much. Typically, consumer cameras hyper-compress, and this leads to problems with certain kinds of material. MPEG compresses static frames and then compresses motion in intervening frames.
DV compresses, among other things, color information, which produces some artifacts that I don't like... but there are ways of making DV look fairly good.
Initially, MPEG's motion compression made it much harder to edit than DV. Generally, I hear, this issue has been more or less resolved. MPEG editors go to an intermediate format... but, depending on all sorts of factors, including the initial degree of compression, there are likely to be losses in this stage.
In thinking about MPEG compression, it's helpful to note that MPEG-compressed video... eg, DVDs for consumer end-use... are held to a lower bitrate, not because of deficiencies in the compression methods, but because of limitations both in disk capacity and in the computing capabilities of the hardware. MPEG for archiving video, eg, is encoded at a much higher bitrate than is MPEG for DVD release. Even on commercially released DVDs where there's scene-to-scene control of the data throughput, I've seen spots that will break up on every DVD player I've tried but which play fine on a computer. This MPEG breakup is typically on material in which there's a lot of motion.
So, in what you're planning to shoot, highly compressed MPEG (as you'll get on a cheap camera) is liable to be less satisfactory in skiing action, snowstorms, fast camera movements, etc. But MPEG might be more attractive than DV on static landscape shots. Hard to say how it would survive decoding and re-encoding.
The use of flash memory, I should mention, also creates some archiving issues, which, IMO, are unresolved.
I think for your subject matter and scale of operation, I'd go for DV. I think at the price range you're talking about, the HD cameras are not likely to be satisfactory.
The GS250 and the GS400, like all consumer cameras, have a lot of tradeoffs, but they've also got a lot to recommend them. From the features and reviews only... and I have no personal experience with either camera... I'd tend towards the GS400. I'm generally impressed by Panasonic.
Both cameras have actual viewfinders. I feel that it's important for a camera that's going to be hand-held to have an actual viewfinder, a feature that's increasingly being eliminated in consumer cameras.
While an LCD screen is a great extra accessory, good for low-angle shots, moving shots while skiing and the like, they're not easy to use outdoors as a primary viewfinder... and the ergonomics of LCD panel viewing only, which require you to extend your arms in front of you to see the screen, are, IMO, ridiculous. This is particularly true on a low-mass video camera.
One more point... to get an idea what kind of image a camera will produce online, do a search for the camera model on various of the video sharing sites. Vimeo in particular has active communities built around various pieces of hardware. You won't know, of course, how the video has been processed, but if you look at the best examples that match the kind of subject matter you'd be shooting, you'll have some basis for comparison.