Talk:PXL-2000
From Wikipedia, the free encyclopedia
Contents |
[edit] Add images of PXL-2000 video
It would be fantastic if some still images could be added. It would demonstrate the visual quality of these camera.
- Where (and how) would you suggest getting one? Seems to me what you'd have to do is a) find a working PXL-2000 and b) find some way of running it through a modern RF modulator. Haikupoet 19:17, 29 May 2006 (UTC)
- I think I remember seeing a PXL 2000 recorded video on the Nirvana With The Lights Out DVD. Is this a PXL video?
- There's a pretty good still on the already linked-to page http://www.members.aol.com/bunchastuf/souvenir.html. It's blown up from its true 120x90 resolution, but since that approximates what happens when the footage is scaled up to NTSC resolution, that's perhaps appropriate. I bet the filmmaker wouldn't mind a still from his film being used as an example on the Wikipedia article. Hmm, the aspect ratio isn't 4:3, though -- wonder if it's cropped... Otherwise, someone could just take a screenshot from a PXL-2000 film -- perhaps one that preserves the gutterboxing like Eli Elliott's http://www.youtube.com/watch?v=BWfM-_SlZIA. --Dan Harkless 22:08, 20 June 2007 (UTC)
- Okay, I went ahead and took a representative screenshot from that video on YouTube that I mentioned (after hitting the button in the YouTube Flash video player that de-stretches the video back down to the native 320x240 resolution), but when I was preparing to upload it I ran across Wikipedia:Non-free_content. Sounds like the image would just be deleted because there's probably some PXL-2000 film somewhere that's been released into the public domain. I'd send a message to Eli Elliott asking if we could use the still I took, but I see the copyright on that particular film is owned by his friend Phil Chamberlin, who has passed away. Unfortunately I'm out of time for working on this further.
[edit] Possible problems with frequency calculations
The text says: "The PXL scanned its 120 by 90 CCD fifteen times a second, meaning that it processed 162000 pixels per second ignoring recovery time; the CCD clocks actually ran at approximately 180kHz. It ran its tape approximately nine times faster than an audio cassette, giving approximately 160kHz of useful bandwidth. This meant that, assuming the tape behaved at specification, it would record only half of the information scanned out of the CCD."
I am not aware of the special properties of this format. However, as an audio and video signal processing professional I see the following problems with this text:
If you are running data at a clock of 180 kHz, you actually need (slightly over) half the bandwidth to store that information, i.e. 90 kHz. However, if an FM signal is to be stored to the tape, it would be very interesting to know both the center frequency, bandwidth and standard deviation of that signal, as they all effect the required medium bandwidth (e.g. FM radio has an audio bandwidth of 15 kHz, but it still requires 200 kHz RF bandwidth). Without that information, we really cannot tell much about the relationship between available bandwidth and how well we can store the CCD signal.
As I don't have the answers (only impertinent questions), I will not change the main page. However, I would like to see the last quoted sentence removed, because bandwidth and "pixel" rate do _not_ have such cause and effect as explained in the article. For the same reason the conclusions drawn in the following sentence don't make much sense to me: "With this in mind, the PXL ASIC applied fairly heavy analogue filtering to the video signal to smooth it on exit from the CCD, then pre-emphasize it, offsetting the disproportionate loss of higher frequencies." While I certainly do believe that lots of filtering is needed between the CCD and tape, and while tape bandwidth is certainly a key reason for filtering, there isn't necessarily a "disproportionate loss of higher frequencies". 120 pixels just isn't very much to begin with and signal processing principles dictate that you have to filter it heavily if you don't want to end up with a pixellated image.
Kind regards, RealLeo 11:09, 3 December 2007 (UTC)
[edit] Killer Me
The film Killer Me, was filmed with a Fisher-Price PXL2000. If you want more information on the film, it's at:
http://www.imdb.com/title/tt0273311/
The sleeve of the DVD also, describes the camera's role in creating the film:
"Writer and director, Zachary Hansen created most of the film's music score, with a children's toy called the Fisher Price PXL2000. The pixel camera captures it's grainy images on a standard audiocassette. Playing back these tapes on a cassette deck, Hansen created eerie, distorted sounds that are as unsettling as the film's images. Also shot with the pixel camera and reprocessed on an Avid, the ghostly images of the opening title sequence provide the audience with a graphic enterance into the disturbed world of Killer Me."
[edit] Eli Elliott
Several PXL movies from prolific pxl filmmaker Eli Elliott are screening online here: www.youtube.com/Elienation