From: wave@waits.media.mit.edu (Michael B. Johnson)
Subject: Re: RenderMan-High resolution rendering?
Organization: MIT Media Laboratory
Date: Fri, 13 Nov 1992 17:08:17 GMT

Allen B writes
> In article <1992Nov12.050629.26616@news.media.mit.edu>  
wave@waits.media.mit.edu  
> (Michael B. Johnson) writes:
> > Here's where you could change the resolution of your image from, say,  
256x128  
> > to whatever you'd like (2048x2048?).  
> 
> Yeah, like most people have a use for a square print.  I'd
> try something like 2048 x 1536 or 4K x 3K.

Geez, Allen, did you have too much coffee this morning?  The number I typed  
above was a typo (clearly, since I was going from a 2:1 aspect ratio to a 1.:1)  
- but, yea, sure, I have a lot of use for square images.  I shoot some 2 1/4,  
which is a square photographic format.  If you do any icons (yea, I know, way  
low rez but) on the NeXT, they are square also Yes, I do use RenderMan to do  
icons.  I model better than I draw).  Lighten up.  The world is not 4:3, or  
even 1.85:1.

> 
> But from reading his posting, I was wondering whether
> this works.  I haven't tried to prman anything bigger than
> the NeXT screen.  Does it crap out at high resolutions? 
> qrman sure crashes a lot. 

prman is probably one of the most robust, well written pieces of software out  
there (especially in the rendering world).  If you have the time and the swap  
space, it will make the picture.  prman is the culmination of some of the  
brightest minds in computer graphics hacking away in a research and production  
environment for many years.  qrman, on the other hand, is very, very new.  It  
will get better, and clearly has a ways to go.

> 
> > Also realize that PhotoCD is takes an analog image (film) and puts it in a  
> > digital form (5 varying resolution images on a CD-ROM).  This is the  
opposite  
> > of what you're talking about doing, which is taking digital imagery and  
> putting  
> > it to an analog form.  Kodak has yet to address this with PhotoCD (other  
than  
> > to say you could go to a photofinishing store and specify your reprints  
> there).
> 
> The highest Photo-CD res I've heard is 4K x 3K.  If you could
> write your image digitally to a Photo-CD, that'd be quite
> convenient.  You'd then be able to do whatever Kodak comes
> up with with your image.  
> 

I don't have the specs handy, but in the last few months, Kodak has announced  
(but not shipped, to my knowledge) a few new types of Photo-CD, the largest of  
which is intended for digital archiving of 4x5s.  I would hope the resolution  
is higher than 4Kx3K, since the high res version of the 35mm consumer product  
is about 3Kx2K...


> > Charlie - supress the urge to do things at 400dpi, unless you are doing  
> things  
> > that are only an inch or two wide.  For rendering, think in pixels, not  
dpi.   
> 
> I disagree.  You should take the requirements of your
> print into account.  I think Photo-CD aims way too low for
> big things like magazine covers- and certainly for
> posters.

Photo-CD isn't aiming for posters, and for a lot of magazine covers, using  
images from a Photo-CD will be fine.  Keep in mind, the Photo-CD that most  
people are talking about is the consumer product, not the pro one.  Even so,  
have you seen the stuff from Kodak where they take the Ektar 25 negative that's  
been put on Photo-CD and then zoom it way up and use that as a 1/4 page color  
image?  It looked pretty sweet to me...


> 
> On the other hand. I think people often overestimate the
> resolution they need.  I've seen things produced for NTSC
> used in print and as slides and they looked great.  It
> depends a lot on sampling and viewing conditions.
> 
> Your best bet, of course, is to experiment.  Anybody who
> prints things will tell you there's nothing like seeing
> it in print to tell you what it'll look like in print.  Same
> goes for film, video, whatever.  If you can do a test print
> (once you find a service), you'll learn more from that
> than speculating.
> 

Very sound advice.  

--

-->  Michael B. Johnson
-->  MIT Media Lab      --  Computer Graphics & Animation Group
-->  (617) 253-0663     --  wave@media-lab.media.mit.edu
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