Re: Paper negatives- Ink Selection
Katharine, The comparison I did was with same printer settings, I think that when printing all inks and reducing the amount of ink by switching from Photo Quality Paper to Plain paper (as does Loris) the exposure times will come down, surely for gum this will not affect the end result. Another thing to try. You're absolutely right about the amount of 1280/1290 cartridges you use when printing colorized so I try now to print grayscale for the separation negatives in gum. Greetings, guido 2008/10/15 Katharine Thayer <kthayer@pacifier.com>: > That's interesting, Guido, thanks. > > What's puzzling to me, in light of your observations, is that when I > switched from greyscale negatives (printed with color inks) to color > negatives, using Michael Koch-Schulte's NLP array to determine the color, it > didn't change my exposure times for gum at all. But, now that I think of > it, I made that change fairly close in time to a change in printers, from > the Stylus Photo EX to the Epson 1280, so it would be impossible to draw > any valid conclusions about the two kinds of negative, because they weren't > made on the same printer or even on the same media (my greyscale negatives > were oiled paper negatives, but my colorized negatives are all on > transparency film). > > But one thing I've noticed is that with the colorized negatives, I go > through color cartridges like nobody's business. Although, again, it's a > different printer, and maybe this printer would also eat cartridges with > greyscale, even though the old one didn't. Too many variables. But anyway, > thanks again. > Katharine > > > > On Oct 14, 2008, at 11:37 AM, Guido Ceuppens wrote: > >> 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 >> Guido >> >> >> 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... >>>>> (!? >>>>> >>> >>> >> > >
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