Date: Fri, 27 Nov 1998 18:37:35 -0800
From: [EMAIL PROTECTED]
TOM:
YOU MIGHT WANT TO TALK WITH BOLESLAW STASICKI, IN GERMANY.
HE PRESENTED A PAPER IN MOSCOW, IN SEPTEMBER, THAT DEALT
WITH CAPTURING CYCLIC EVENTS USING STANDARD VIDEO CAMERAS.
THE TECHNIQUE PRODUCES EXCELLENT RESULTS.
I'M SENDING A COPY OF THE INFORMATION YOU HAVE PROVIDED TO
BOLESLAW. I'M SURE HE'LL GET BACK TO YOU SOON.
Jim Walton
P.S. To other subscribers to the "High-speed" list, my
apologies for duplicating the following material.
I want to bring Boleslaw Stasicki up to date with
the relevant information before he describes the
work he presented in Moscow. I think you'll find
it quite interesting. His results were phenomenal
and they appear to relate directly to Tom's request.
*****************
ORIGINAL REQUEST ...
On Thu, 26 Nov 1998, Andrew Davidhazy <[EMAIL PROTECTED]> wrote:
>Date: Thu, 26 Nov 1998 09:36:59 +0200
>From: Tom Cichoracki <[EMAIL PROTECTED]>
>
>Dear SPIE Members,
>
>I need to build a high speed imaging system and know little about optics.
>There is a lot of information concerning optics/photonics and hope someone
>could suggest books, literature, or give suggestions on designing and
>building a high speed imaging system.
>
>Below is a brief description of what I want to do.
>
>I have a 165 mm diameter rotor rotating at up to 3000 rpm (26 m/s) in a
>wood fiber/water suspension. I want to view phenomena (as small as 30
>microns and up to 10 - 20 mm) at the rotor surface by drilling holes in the
>rotor in the axial direction for a periscope and in the radial direction
>for a view port at the rotor surface. Due to the high speeds, small objects
>and darkness in the measurement area I also need to feed sufficient light
>(fiber optics) to the measurement area. One side of the experimental device
>is plexi through which the images must be captured and the illumination
>light fed.
>
>From the imaging results I hope to gain information concerning fiber bundle
>size as well as fiber bundle and individual fiber velocity (both magnitude
>and direction).
>
>One problem I foresee is the reflection of the illumination light off the
>view port and how the light must illuminate the view area so that I get
>contrast. Vibration of the device may cause additional problems.
>
>Since high speed video is expensive, I thought that a CCD camera and
>stroboscope could be an economical solution.
>
>I understand it may be difficult to get a picture of this system, but any
>comments, suggestions or literature would be greatly appreciated.
>
>Sincerely,
>
>
>Tom Cichoracki
>TKK
>Puunjalostustekniikan osasto
>PL 6300
>02015 TKK
>
>puh. (09) 451 4291
>puh. 050 522 3792
>fax. (09) 451 4259
**************************************
RESPONSE FROM CHUCK PETERSEN AT EPIX, FOLOWED BY TOM'S RESPONSE ...
CHUCK AT EPIX:
>Tom,
>
>If you are interested in capturing image sequences from your system,
>a camera is required that will run at as high a frame rate as you need.
Actually, I had the idea that if I could have a high intensity stroboscope
which could produce short multiple pulses, I could actually get motion
phenomena on one frame/picture. So, two pulses would be enough to determine
size, speed and direction, more than two stroboscope pulse would also give
path information. The problem is I am not sure how to get the whole thing
to work (if it will work).
>We have used various Dalsa cameras, the latest is a 256 by 256
>Motion Vision camera that operates at 955 frames per second.
>This camera requires some type of flashed light to stop motion.
>We have used a LED ring lamp successfully, but we are dealing
>with objects moving at 60 miles an hour. Sounds like your system
>is much faster.
>
TOM:
I do not actually need a consecutive sequence of images, since the
phenomena occurring in my device occur repeatedly. It is not like videoing
a car crash or books falling. However, if HS video is reasonably priced an
imaging sequence would be nice to have for reporting and playback.
Actually, if I have calculated correctly 60 mph = 30 m/s. My max. is
slightly less than this.
I have up to 24 "wings" on my rotor which turns at a max. of 50 Hz
resulting in a freq. of 1200 Hz. If I were to capture a sequence of images,
I would need at least that speed.
>If you are interested in capturing a sequence of images at 30 frames per
>second, a gated intensifier on a 30 frame per second camera may be adequate.
>You can try Xybion which makes gated intensified cameras.
>
I do not know anything about gated intensified cameras.
**************************************
END OF RELEVANT DIALOG
Jim WALTON
Chairman-Elect, SPIE Working Group on High-Speed Photography,
Videography and Photonics
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