Digital BW, The Print

In a message dated 6/15/2003 6:42:57 AM Eastern Daylight Time, 
DigitalBlackandWhiteThePrint@yahoogroups.com writes:

> I'm curious about this comment.  Does anyone know what a lightjet/RA-4
> process is capable of with respect to dmax on RC papers?  The dmax of silver
> papers is typically not as high compared to what you can get with
> Ultrachromes on RC papers with photo black. Is it possible that the
> Ultrachromes are outperforming the lightjet/RA-4 workflow with respect to
> blacks?  I assume that lightjet/RA-4 is still the color gamut winner,
> however?
> 
> Robert
> 

According to a conversation I just had with Bill Atkinson, the Dmax and tonal 
gradations (like sky) are higher and smoother, respectively on a Lightjet 
with Fuji Crystal Archive PROVIDED that the lab has their calibration/management 
act together.

The 9600 Ultrachrome output on the RC paper has a bit less Dmax (an vastly 
overrated criteria in my opinion) but much better tonal separation in the 
yellows.

I have seen fine examples of both.

Claude Jodoin
Technical Editor
Rangefinder Publications
& Working Photographer


[Non-text portions of this message have been removed]

In a message dated 6/15/2003 6:42:57 AM Eastern Daylight Time, 
DigitalBlackandWhiteThePrint@yahoogroups.com writes:

> The best you get is 100, the WORST you get is 50.  In reality, you get a
> range of 50-100.  The 50 would be called "RELIABLY".
> 
> Austin
> 

Correct me if I'm wrong, but historically, haven't we put the lens MTF in 
parallel with the film MTF? Like tow 100 ohm resistors in parallel and invert the 
sum of their inverses in the process? and is "reliably"/planning for worst 
case? According to this formula, if either of the MTFs is any lower, the total 
MTF would be less than 50, reliably. If there's a more accurate formula, please 
enlightent me.

Claude


[Non-text portions of this message have been removed]

Claude,

> > The best you get is 100, the WORST you get is 50.  In reality, you get a
> > range of 50-100.  The 50 would be called "RELIABLY".
> >
> > Austin
> >
>
> Correct me if I'm wrong, but historically, haven't we put the lens MTF in
> parallel with the film MTF? Like tow 100 ohm resistors in
> parallel and invert the
> sum of their inverses in the process? and is "reliably"/planning
> for worst
> case? According to this formula, if either of the MTFs is any
> lower, the total
> MTF would be less than 50, reliably. If there's a more accurate
> formula, please
> enlightent me.

Yes, electronically, 100 ohms in parallel with 100 ohms does give you 50
ohms, but electronics are not the same as optics and film.  Film records the
data just like a CCD array does, using discrete elements.  If the photons
being "measured" happen to fall right on the sensing area, it will record at
that resolution, if it happens to straddle two sensing areas, it'll record
half that resolution.  What you will get are values from %50 gray on two
adjacent sensing areas, to one %100 white and one %100 black (if you are
using a test pattern that is).  Of course, film grain size is random, but
still within a rather narrow size band.

It's more than a formula, it's an understanding.

Austin

Ahh...
You Wrote Austin:
"> It's more than a formula, it's an understanding."

OK!

"It's more than resisters, it's about understanding!"

Sorry... could not "RESIST".

Are you happy with what you see, fellows? 
Try everything you can buy, and don't "RESIST"!

Lux!
Bo Wrangborg
Swedish Team




--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Austin 
Franklin" <darkroom@i...> wrote:
> Claude,
> 
> > > The best you get is 100, the WORST you get is 50.  In reality, 
you get a
> > > range of 50-100.  The 50 would be called "RELIABLY".
> > >
> > > Austin
> > >
> >
> > Correct me if I'm wrong, but historically, haven't we put the 
lens MTF in
> > parallel with the film MTF? Like tow 100 ohm resistors in
> > parallel and invert the
> > sum of their inverses in the process? and is "reliably"/planning
> > for worst
> > case? According to this formula, if either of the MTFs is any
> > lower, the total
> > MTF would be less than 50, reliably. If there's a more accurate
> > formula, please
> > enlightent me.
> 
> Yes, electronically, 100 ohms in parallel with 100 ohms does give 
you 50
> ohms, but electronics are not the same as optics and film.  Film 
records the
> data just like a CCD array does, using discrete elements.  If the 
photons
> being "measured" happen to fall right on the sensing area, it will 
record at
> that resolution, if it happens to straddle two sensing areas, it'll 
record
> half that resolution.  What you will get are values from %50 gray 
on two
> adjacent sensing areas, to one %100 white and one %100 black (if 
you are
> using a test pattern that is).  Of course, film grain size is 
random, but

> still within a rather narrow size band.
> 
> It's more than a formula, it's an understanding.
> 
> Austin