U of S | Mailing List Archive | alt-photo-process-l | Re: Paper negatives- Ink Selection

Re: Paper negatives- Ink Selection

Since the original post questioned the list on their ink settings I
did another comparision:
my previous post gave MY exposure times in MY setup using oiled and
un-oiled paper using a colorised negative, so I now did a furter test,
again with cyanotype (cheap and quick) using Chartthrob.
A Grayscale_Chart printed with a color 0;255,21 printed OK with an
exposure of 8 mins (ChartThrob white at 2, black at 100).
A Grayscale_Chart printed with All Inks needed an exposure of 24 mins
to arrive at the same density/tonal scale (ChartThrob white at 2,
black at 99).
 Funny enough the resulting curves were almost identical. I print with
an Epson 1290 using third party inks on Epson PQP oiled.
So does a correctly colorised negative aid in more speed when
printing? For me, maybe yes, but an all inks setup might be (a lot)
cheaper, especialy when using Epson single-color cartridges

2008/10/14 Loris Medici <mail@loris.medici.name>:
> Katharine, don't worry I'm pretty careful about this subject - knowing (by
> experience) you'll chime in every time it's brought up, to clarify ;) I'm
> getting older I guess; less and less surprises... ;)
> I wasn't attributing the short exposure I'm using to curves at all, that
> was a side note (which should have been enclosed between parenthesis,
> sorry). I was trying to say (indirectly) that since the DR (=density
> range) and tonal progression of my paper negatives (made with the HP 9180
> all-inks grayscale setting, using the printer's plain paper profile) are
> close to ideal (in tricolor gum printing context - which is supported by
> the fact that the curve I devised for this particular combination is the
> smoothest and least dramatic one among all curves I did until now),
> therefore, other people's longer exposure times could be caused by the
> fact that they're using negatives with more DR, which naturally will
> require more exposure and a stronger / more dramatic curve to
> counterbalance. Or they're not calibrating, or their calibrations are
> flawed...
> Hope it's clear, and makes more sense to you now. I perfectly understand
> the confusion I may have caused on your part.
> Regards,
> Loris.
> P.S. BTW, I have compared my times with the times of people who use
> similar light source, emulsion, negative media and working procedures. I'm
> perfectly aware of the parameters affecting exposure time and pay
> attention to them.
> 14 Ekim 2008, Salı, 7:18 pm tarihinde, Katharine Thayer yazmış:
>> Loris, I'm wondering what data you're basing this last bit on, that
>> other people's exposure times are longer than yours.   It's generally
>> not useful to try to compare exposure times because there are so many
>> variables involved, but putting that aside for a moment,  I've looked
>> back through this thread, and the only reference to exposure times I
>> can find is Guido's comparison between oiled and unoiled Epson PQ
>> paper, 8 vs 48 minutes, with cyanotype.  Since it was  cyanotype, and
>> since the paper is a heavier paper (27 pounds) than yours,  it's not
>> surprising that his exposure time for unoiled paper would be longer
>> than yours, and we haven't even got to light source yet;  to reach
>> immediately to curves to account for a difference in exposure times
>> seems rather a long stretch to me.
>> Perhaps I've missed other posts that included exposure times for gum
>> and paper negatives (my server doesn't accept some of the alt-photo
>> mail, so I don't always see all the posts).   At any rate, my times
>> with oiled paper negatives run close to my times with inkjet
>> transparencies, about 3 minutes,  to add to your database on exposure
>> times.  I don't have any comparison with unoiled paper to offer,
>> because that's not an option that makes any particular sense to me.
>> But be that as it may, I can't see any reason why curves would
>> account for a difference in exposure time.  After all, the exposure
>> time is determined before curves are even calculated, at least that's
>> how it is with the system I use, and I assume it's the same with all
>> systems; the curve doesn't change the exposure time.  Besides, curves
>> simply redistribute the tones within the print tonal range that
>> particular emulsion can print under that particular protocol; they
>> don't extend it, so there's no logical reason curves would have any
>> effect on exposure time.
>> Katharine
>> On Oct 12, 2008, at 11:23 AM, Loris Medici wrote:
>>> I use the grayscale using all inks (not black and gray - if present
>>> - inks
>>> only), plus, I choose plain paper as the media. Fortunately, with
>>> my inks
>>> the printer lays just enough ink giving an almost perfect negative in
>>> terms of density range (something around log 1.0), and the curve I
>>> use for
>>> gum prints are is the least drastic and most smooth one among my
>>> curves
>>> collection for many processes and paper. In fact, I think that's
>>> why other
>>> people's exposure times are considerably longer compared to mines...
>>> (!?