Digital BW, The Print

On 3/20/03 11:56 AM, "jim hayes" <jimhayes@...> wrote:

> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, Robert Morrison
> <rmorrison@p...> wrote:
> 
>> Have you looked at step wedges/gray ramps for these two workflows?
>> 
>> I don't know about the RGB workflow for VM, haven't used it, but I
> can say
>> with absolute certainty after a lot of testing and densitometer readings
>> that IP with the 2200 is no where close to an Ames curve.  Shadow detail
>> from 90 to 100% is completely non-existent.  Transitions in midtones are
>> very smooth with the 2200 and IP.
> 
> You'd be more of an expert Robert, but yes, as I posted, on Paul's
> step wedge the 95-100% by 1% section blends into each other, and
> distinctions are hard to see (this is 2200/IP5). When I put the 95%
> step next to the 100%k step there is somewhat a diff. And I can just
> barely see a diff between 95 and 96%k but I have to look REAL hard.
> Therefore I concluded that 96-100%k WAS compressed. On previous wedges
> done with Paul's VM curves the 95-100% k was more defined.
> 
> I haven't compared 1%k squares from 90 to 95%k but I can see a
> definite diff between 90 and 95%k strip. That's about the extent of my
> observations. I know on my prints I have had some shadow dropout, yes.
> 
Following an Ames curve for either Gamma 1.8 or 2.2, the visual difference
between 95% and 100% should be very large and easy to see...it is not with
IP.  Likewise the 90% to 95% transitions should be  much larger than than
they are with Imageprint.  This is easy to measure...something I have done
repeatedly for both their 2200 profiles and also their profiles for the 7000
with the Piezotones...they simply don't get it.
> 
> <snip>
> 
>> 
>> Using another driver (Ink Jet Control) to run the 2200 you can get
> beautiful
>> step wedges with just two inks (light black and black) that
> perfectly follow
>> an Ames curve.  They look very similar to Cone's Sepia
> Pieztones...however
>> slightly warmer.
> 
> Are you saying these are in effect Sepia toned and can't get any colder?

No, you just add cyan and magenta to make them cooler...just like IP5 does.
The problem with IP5 is that you can't get warmer (without switching to full
color inks).  Interestingly the shadows are still compressed...but much less
so with IP5's color profiles.
 
Robert