Re: filmscanners: Pixels per inch vs DPI

[Arthur Entlich <artistic@ampsc.com>]

The original HP Photosmart printer (the big boxy one), which at the time
produced some of the best photo-quality images that came out of an
inkjet printer, was designed around input of 100-150 ppi, and used 300
ppi output based upon a 6 "color" (CcMmyK) process.  In fact, if memory
serves me, it couldn't use input over 150 ppi.  The process used a type
of overprinting - laying down more than one ink drop per location, which
is why HP didn't like to speak about output dpi, because they felt it
unfairly sounded too low compared to competitive products, which at that
time, were claiming up to 720 dpi.

And, because I know Austin will ask, this came from the guy who wrote
the printer drivers.

Art

Wire Moore wrote:

 > Actually, I'm blind. I was in despair until I found this photography 
hobby.
 > Now it's all that keeps me going...
 >
 > Seriously, I mean 100 ppi sent to the printer, not a 100 pixel wide 
image! I
 > have standards.
 >
 > ...
 >
 > OK, the truth is I have very low standards...
 >
 > Oh, never mind. I shouldn't have said anything :)
 >
 > Wire
 >
 > on 10/25/01 7:21 PM, Austin Franklin at darkroom@ix.netcom.com wrote:
 >
 >
 >>>>Austin wrote:
 >>>>
 >>>>>Why would you want to output at a fixed 300 PPI?
 >>>>>
 >>>>Because that's the requirement of the offset printer which many
 >>>>
 >>>of my recent
 >>>
 >>>>photos are going to.  Aside from that, 300 dpi is as a general
 >>>>
 >>>rule of thumb
 >>>
 >>>>the "best" resolution *most* printers (pc and otherwise) work
 >>>>
 >>>with.  Some
 >>>
 >>>[snip]
 >>>
 >>>After working with 4-color Epsons for a few years, I've found that the
 >>>resolution demands of photographs can be quite low, where as few
 >>>as 100 ppi
 >>>as a lower limit can produce nice results.
 >>>
 >>You must be talking about very small images, from a very poor negative.
 >>There is absolutely no chance that I can get a "quality" image at 100 ppi
 >>from my images, 35mm or 2 1/4.  I really can't imagine every seeing a 
100ppi
 >>output that was "nice"...  Even 180 is too low, except for the largest of
 >>images I print.  240 is about the minimum acceptable resolution I can 
send
 >>to the printer, or image quality degrades quite noticeably.  We obviously
 >>have different standards is all I can guess.
 >>
 >>
 >>>There's a book called "Real World Scanning & Halftones," which explains
 >>>print dots (spots) in depth.
 >>>
 >>Got it, it's a reasonably good book.
 >>
 >>
 >>
 >
 > .
 >
 >