Digital cameras

[Ed Sutton]

Stephen-

One of the most exciting parts of the Kimball?Baldwin? movie was the image of the
wave crashing along the string like a tidal wash in a hurricane.  I hope your
project will try some videos of string motions, and wonder if some of our voicing
questions (such as aliquot zingers) might be made visible.

Ed Sutton


----- Original Message -----
From: "Stephen Birkett" <sbirkett@real.uwaterloo.ca>
To: "College and University Technicians" <caut@ptg.org>
Sent: Thursday, November 13, 2003 11:22 AM
Subject: RE: Digital cameras


> Don wrote:
> >The recent Kawai digital films have still been done with high speed
> >film, not with digital cameras.  Digital CCDs are still very slow
> >compared to the special films.  13,500 frames per second is still beyond
> >digital, as far as I know.
>
> Speed isn't an issue now for high speed digital imaging. For $50K
> you can get a camera system that will do imaging up to 16,000fps in
> greyscale. For $150K you can get a maximum 100,000fps in colour.
>
> Resolution and field of view are more significant issues than fps if
> you're using these for data collection, as we are in our
> experimentation. Basic CCD resolution is of course fixed, and seems
> to be typically 1280x1024 pixels [market pressure went in the higher
> speed, moderate resolution direction]. This can be distributed over
> the field of view any way that your optics permits. Data is
> transferred in real time to a PCI buffer that is as big as your
> memory budget $ allows, but tends to fill up fast with megapixel
> frames coming in at ms rates. As the buffer fills it flushes the
> earlier data. You can choose what you capture according to whatever
> type of trigger system is best. There is a maximum data transfer rate
> which restricts field of view after some cutoff fps value. After
> that, each time you double fps you halve field of view to keep the
> pixels per frame the same. Being digital is nice because you can sync
> with actuation devices and other data collection signals, e.g. from
> force detectors, even add that information to the frames if you like.
>
> For qualitative observation of piano action behaviour 1000fps is
> generally ok  - much of our imaging is done at that frame rate. Gives
> you one image per ms. Moving parts at 1m/s translate to 1mm/ms, so
> 1mm change per frame.
>
> My grad student has posted some cool movies of bubbles and droplets
> he took while learning how to use the camera....
> http://real.uwaterloo.ca/~martinh/
>
> >I had no idea. Are the Kawai tapes "top
> >secret", for Kawai use only, is there any access to them by technicians,
> >or do we get a chance to see them in Tennessee?
>
> What do you want to know?
>
> Stephen
>
>
> --
> Dr Stephen Birkett
> Associate Professor
> Department of Systems Design Engineering
> University of Waterloo
> Waterloo, Ontario
> Canada N2L 3G1
>
> Davis Building Room 2617
> tel: 519-888-4567 Ext. 3792
> PianoTech Lab Ext. 7115
> mailto: sbirkett[at]real.uwaterloo.ca
> http://real.uwaterloo.ca/~sbirkett
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