g8@anuck.UUCP (k.d.tentarelli) (02/14/89)
Can anyone answer some general questions on film recorders as
graphical output devices?
1. Do they use CRT technology?
2. Does the resulting film show individual pixels, or do the pixels
scatter when being recorded such that the film looks continuous?
3. How good is the color fidelity? (I'm not sure of the best measure
to use for this. Perhaps consitency of reproduction is a good
measure since any static color error could presumably be
compensated for.)
Thanx
--
"thanx for the use Ken Tentarelli
of the network" ATT-BL, Andover, MA. att!angate!g8dplatt@coherent.com (Dave Platt) (02/15/89)
In article <1479@anuck.UUCP> g8@anuck.UUCP (k.d.tentarelli) writes: > Can anyone answer some general questions on film recorders as > graphical output devices? I've recently been working a bit with Marc Kaufman, who wrote the Mac "printer"-driver for the Mirus slidemaker. Marc has been able to "print" slides using the most recent version of my Mandelbrot-set program. We've had some discussions about the technology that Mirus uses in their device, in the course of tuning the program. > 1. Do they use CRT technology? The Mirus uses a single monochrome CRT. It "prints" in three passes, by dropping red/green/blue filters between the camera and the CRT. > 2. Does the resulting film show individual pixels, or do the pixels > scatter when being recorded such that the film looks continuous? Yes. ;-} The beam-spot on the Mirus CRT is somewhat larger than an individual pixel. The device's sweep-electronics handle a resolution of 1500 wide by 1000 high (and I believe they'll slice even finer), but the pixel-spots will overlap somewhat at this resolution. In areas of uniform color, the blend between pixels is quite seamless... I've projected one of these slides, and the only graininess I could see was due to the film itself (Ektachrome 100, I believe). The driver-software will dither areas of closely-related colors, thus providing a very smooth blending. There is none of the characteristic squarish shadow-mask graininess that's observable on the AppleColor monitor (and most other color monitors, I believe). Things don't work so smoothly when pixels of contrasting colors lie adjacent to one another, though. If a red pixel adjacent to a green pixel, there will be an area of yellow where the CRT spots overlap. This is unfortunate, but appears to be inherent in the technology that Mirus is using. Mirus is aiming at the business-presentation market rather than the scientific-visualization market, and have accepted somewhat lower device resolution to help them keep the cost of the equipment down. Marc tells me that it's possible to see individual pixels even at the device's highest resolution, but that the beam-overlap does cause color artifacts. > 3. How good is the color fidelity? (I'm not sure of the best measure > to use for this. Perhaps consitency of reproduction is a good > measure since any static color error could presumably be > compensated for.) I was very impressed. Color balance appears to be an excellent match to the AppleColor monitor I use at home. Marc tells me that they use a gamma-corrected color table. The driver-software permits you to identify the specific slide-film being used; I suspect that the gammas are tweaked in order to match the needs of individual films. I think the color-matching used by the Mirus driver is distinctly superior to that achieved by photographing the AppleColor monitor. -- Dave Platt FIDONET: Dave Platt on 1:204/444 VOICE: (415) 493-8805 UUCP: ...!{ames,sun,uunet}!coherent!dplatt DOMAIN: dplatt@coherent.com INTERNET: coherent!dplatt@ames.arpa, ...@sun.com, ...@uunet.uu.net USNAIL: Coherent Thought Inc. 3350 West Bayshore #205 Palo Alto CA 94303
Classic_-_Concepts@cup.portal.com (02/20/89)
> Can anyone answer some general questions on film recorders ...
The answers to your questions depend on your target price range.
A crude classification would put film recorders into 4 categories:
Lens Hood
This is nothing more than a shield which attaches to your
monitor and prevents glare. They range from $25-$200 and
do not eliminate jaggies, raster lines, etc.
Low-end output devices
These output the signal (usually RGB) to a 'box' which houses
a small flat display screen and a camera. The colors are
quite crisp and warm, resolution is usually about 2k x 2k
and raster lines are not glaringly apparent. Prices range about
$800 - $3,000. They're acceptable for many applications.
Medium range output devices
These are similar in concept to the above, but also usually
include some processing which can take vector-format graphics
and reproduce them at about 4k x 4k +. They are larger and the
results are clean, rich colors and negligible raster lines.
I think HP has some nice models in this range ca. $8000 - $20,000
These are often the ones people would like, but, because of
budget considerations, they defer to 2K x 2K. Very nice, though.
High end output devices
MDA makes some outstanding photoplotters which can output to film
at, I think, up to about 4,000 line resolution (compare this to
a magazine photo which is usually about 250 line resolution).
My guess at the prices on these is about
$60,000 - $100,000+. \_
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\\/// _______________________________________________ ///\\\ hafner@unizh.ifi.unizh.ch (Assi Prof. Stucki) (03/22/91)
If anyone has a survey at hand about available digital film/slide-recorders, their technical specifications, weak/strong points and price-ranges, please post or email it. I'm interested in models starting with a few thousand $ and going up to several tenthousand $.