Re: suitable scanners PMA 02 Orlando

["Willem-Jan Markerink" <w.j.markerink@xxxxx>]

On 25 Jan 02 at 11:35, Phil.Lippincott wrote:

> Hi Richard,
>    All film is not made equal regarding grain.  Nor are all scanners made equal
> regarding optical visibility of resolution.  Just because a scanner creates a
> particular dpi scan 4000 or other resolutions doesn't assure what you really
> get.  So I've spent years testing now various scanners and films to find out
> what is needed and what can the scanner see.
>    If your shooting color negative films and have an honest 2800 dpi scanner
> your right you generally won't totally benefit from a better scanner.  Negative
> films vary in optical grain size of between 14 to 20 microns.  A micron is
> 1/1000 of a millimeter.  A B/W negative generally is between 3 to 6 microns and
> a chrome between 5 to 10.  The scanners are another story all together.  A
> perfectly focused 4000 dpi scanner that can absolutely hold it's spot without
> lens or other artifacts has a 6 micron spot size.  There are by the way very
> few scanners this good.  Yet this is exactly what is required to get in the
> ball park of the grain quality of transparency chromes.  Yet if we want a
> substantial enlargement or faithful capture to the grain of the best chromes
> and B & W negatives we need better than 6 microns or 4000 dpi.  This is why
> when people really need the ultimate quality a 3 micron or 8,000 dpi scanner
> can make sense too.  Yet if only a few scanners can do 6 microns then obviously
> even fewer can do 3.  A 50" x 70"        Also if you don't have grain
> management software tools in the scanning  application software, a very good
> scanner can instead of producing optically pure results produce grain noise.
> Of course very skilled people may be able to manage the many variables
> involved, but it's real hard and many very knowledgeable people claim it's not
> possible.
>    This is one of the reasons for my personal research in this area.  I have
> created software tools to address this issue and created a patented feature of
> my firm's Digital PhotoLab scanning software.  Simply to manage through
> artificial intelligence in software the scanner capture spot size and dynamic
> range to match the media grain and density fidelity. This to assure the
> faithful flawless optical capture of the analog film original digitally.
> Results can be dramatic and easy to use.  If interested you can read about it
> at     www.aztek.com
>    Also if anyone on this list is interested in this and the comparisons I have
> found in the various scanners tested over the years;  I am giving a lecture
> with this information at PMA in Orlando on Feb. 23 next month as part of the
> DIMA conference.  The title of the session is photo digital imaging   "Scanner
> Roundup".  I will be reviewing certain:  Creo Scitex, Umax, Polaroid, Nikon,
> Howtek, Imacon, Aztek, Contex, Epson  and other scanners with the same direct
> scanner density and optical resolution benchmarks.  I will also compare the
> scanner performance to the film requirements in order to attempt to address the
> issue of what scanners are better for what requirements.    I hope that it will
> be an appreciated contribution to the industry and people hungry for
> information to make informed scanner decisions.

Phil, in this context, do you have any explanation why the
old Leafscan45 has such a good reputation for B/W scans? 

It uses an ND-filter for that purpose, instead of a tri-color 
combination as most other scanners seem to do (do they?), but I 
haven't seen a good explanation yet on the Leafscan Mailinglist.... 

--                 
Bye,

Willem-Jan Markerink

      The desire to understand 
is sometimes far less intelligent than
     the inability to understand

<w.j.markerink@a1.nl>
[note: 'a-one' & 'en-el'!]
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