[alt-photo] Re: Your Approach to Making Negs for Platinum Printing? Ideal Negative Contrast and Dmax?

[Francesco Fragomeni]

Thank you!!

-Francesco

On Sun, Oct 9, 2011 at 6:17 AM, Kees Brandenburg <workshops at polychrome.nl>wrote:

> Hi Francesco,
>
> Copies of the old and the new archives are here:
>
> http://altphotolist.org/
>
> kees
>
>
>
> On 9 okt. 2011, at 00:52, Francesco Fragomeni wrote:
>
> > Also, so you can all see what I'm seeing, below are the archives I am
> able
> > to find:
> >
> > http://lists.altphotolist.org/pipermail/alt-photo-process-list/ November
> > 2009 - Today
> > http://www.usask.ca/lists/alt-photo-process/ 1994- August 2006
> >
> > I cannot find any archive containing the gap between August 2006 and
> > November 2009.
> >
> > -Francesco
> >
> > On Sat, Oct 8, 2011 at 3:20 PM, Francesco Fragomeni
> > <fdfragomeni at gmail.com>wrote:
> >
> >> My issue is that most of the information I'm finding is just speaking in
> >> general terms rather then specific empirical measurements. Most sources
> talk
> >> about increasing development to achieve greater contrast or exposing one
> way
> >> or the other. All of that is nice but lacks any actual measurements. Now
> I'm
> >> very visual in how I work but having numbers to back you up can really
> be
> >> quite effective in reinforcing the visual decisions being made. Thats
> why
> >> I'm interested in ideal density numbers for platinum and its why some of
> the
> >> points Etienne touched on were of interest to me. I know I need a neg
> with
> >> more contrast and I know how to achieve that. I'm trying to get away
> from
> >> generalities. I want to know actual density measurements so that I can
> use
> >> my densitometer to read my negs to confirm that I am achieving what I
> want.
> >> I'm trying to use the empirical measurements as a reinforcement and
> >> supplement to my visual process.
> >>
> >> I hope that makes sense and I don't sound crazy.
> >>
> >> -Francesco
> >>
> >>  On Sat, Oct 8, 2011 at 3:12 PM, Francesco Fragomeni <
> >> fdfragomeni at gmail.com> wrote:
> >>
> >>> I found some links to what look like much better archives. I'll start
> >>> digging. Thanks as always Don!
> >>>
> >>> I'm still hoping Etienne can expand a little bit on the densitometer
> >>> density range bit of the converasation.
> >>>
> >>> -Francesco
> >>>
> >>>
> >>> On Sat, Oct 8, 2011 at 2:56 PM, Don Bryant <donsbryant at gmail.com>
> wrote:
> >>>
> >>>> You can start with this one here below by former list member Carl
> Weese
> >>>> (co-author of 'The New Platinum Print'):
> >>>>
> >>>>
> >>>>
> http://theonlinephotographer.typepad.com/the_online_photographer/2010/04/the
> >>>> -making-of-a-platinum-print-slideshow.html
> >>>>
> >>>>
> >>>>
> >>>> -----Original Message-----
> >>>> From: alt-photo-process-list-bounces at lists.altphotolist.org
> >>>> [mailto:alt-photo-process-list-bounces at lists.altphotolist.org] On
> Behalf
> >>>> Of
> >>>> Francesco Fragomeni
> >>>> Sent: Saturday, October 08, 2011 5:34 PM
> >>>> To: The alternative photographic processes mailing list
> >>>> Subject: [alt-photo] Re: Your Approach to Making Negs for Platinum
> >>>> Printing?
> >>>> Ideal Negative Contrast and Dmax?
> >>>>
> >>>> Don,
> >>>>
> >>>> I must be looking inthe wrong places. I figured there must have been
> >>>> plenty
> >>>> of this discussion before. I'll look through the archive link I have.
> >>>> Maybe
> >>>> I have a weird link or I just want paying attention. I'll look through
> it
> >>>> all again.
> >>>>
> >>>>
> >>>> -Francesco
> >>>> On Sat, Oct 8, 2011 at 2:29 PM, Francesco Fragomeni
> >>>> <fdfragomeni at gmail.com>wrote:
> >>>>
> >>>>> Etienne,
> >>>>>
> >>>>> Wow! Thanks for all for all of the info. I'm only working with large
> >>>> format
> >>>>> negatives (I shoot 8x10 and larger) in this case so my follow up is
> in
> >>>>> regard to what you posted regarding in-camera negatives and not the
> >>>> extra
> >>>>> digital stuff.
> >>>>> "Below are some observations I have made in the past (you will find
> >>>>> others in the list archives, from me and others).  For the
> traditional
> >>>> Pt
> >>>>> process, you want a negative with a density range ("DR") of 2.0 or
> >>>> higher
> >>>> (I
> >>>>> generally aim for 2.4) to get both Dmin and Dmax in the print.  Note
> >>>> that
> >>>>> not all films available today will produce such a DR, no matter how
> you
> >>>>> expose and develop them.
> >>>>> BTW, I encourage everyone to stop speaking of "stops" and "contrast
> >>>> range"
> >>>>> -- much better to identify clearly what you mean and speak of
> "exposure
> >>>>> scale" ("ES") and "density range" ("DR"), to make sure we are always
> >>>> keeping
> >>>>> the distinction in mind.  On this, see my message of 11 Oct 2009, in
> >>>> the
> >>>>> archive.  For example, while the ES of traditional Pt is around 2.1
> to
> >>>> 2.4
> >>>>> (and, therefore, a negative that produces a full-scale Pt print will
> >>>> have
> >>>> a
> >>>>> DR of 2.1 to 2.4), the full-scale DR of the Pt print itself is much
> >>>> lower
> >>>> --
> >>>>> only 1.4 to 1.7 (the latter only with heroic efforts)."
> >>>>>
> >>>>> I definitely agree with what you're saying. I often get confused with
> >>>> all
> >>>>> of the different terminology. When you say DR do you mean the range
> >>>> between
> >>>>> FB+F and the most dense tone in the negative? I have a X-Rite
> >>>> transmission
> >>>>> and reflection densitometer at home and I'm unsure of how to read a
> neg
> >>>> to
> >>>>> determine is DR or a prints ER. Is it simply reading most dense area
> >>>> and
> >>>> the
> >>>>> least dense area and taking the difference? My processes are always
> >>>> much
> >>>>> more visual then technical but I'd like to grasp an understanding of
> >>>> how
> >>>> to
> >>>>> make all of these measurements so that I can empirically understand
> >>>> what
> >>>> I'm
> >>>>> visually seeing and doing.
> >>>>>
> >>>>> I am specifically interested in figuring out how to properly measure
> >>>> the
> >>>>> density range in a negative so that I can match my visual
> understanding
> >>>> of
> >>>>> what these negatives look like to the actual measurement of the
> >>>> negatives
> >>>>> density range. I hope that makes sense. I suppose I'm just looking
> for
> >>>> a
> >>>>> little clarification on the best practices for using a densitometer
> and
> >>>> how
> >>>>> to relate the measurements to density range and exposure scale.
> >>>>>
> >>>>> Thanks so much for the help!
> >>>>>
> >>>>> -Francesco
> >>>>>
> >>>>>
> >>>>>> Francesco wrote:
> >>>>>>
> >>>>>>  Now that I'm
> >>>>>>> venturing fairly aggressively into platinum, I'm very interested in
> >>>>>>> hearing
> >>>>>>> how you all approach making your negatives for platinum. I'm
> speaking
> >>>>>>> specifically about in-camera negatives (no digital negs or other
> >>>>>>> processes
> >>>>>>> here). Achieving the ideal contrast for platinum is what I'm
> >>>> interested
> >>>>>>> in.
> >>>>>>> For silver, a negative with a contrast range of around 3.5 stops
> will
> >>>>>>> print
> >>>>>>> well on a grade 2 filter or paper. There is also a ideal negative
> >>>> dmax
> >>>>>>> that
> >>>>>>> some people use as a standard to shoot for but I'm not sure what
> that
> >>>>>>> number
> >>>>>>> is. As I understand it, platinum calls for greater contrast to take
> >>>>>>> advantage of the longer tonal range of the platinum process.
> >>>>>>>
> >>>>>>
> >>>>>> Below are some observations I have made in the past (you will find
> >>>> others
> >>>>>> in the list archives, from me and others).  For the traditional Pt
> >>>> process,
> >>>>>> you want a negative with a density range ("DR") of 2.0 or higher (I
> >>>>>> generally aim for 2.4) to get both Dmin and Dmax in the print.  Note
> >>>> that
> >>>>>> not all films available today will produce such a DR, no matter how
> >>>> you
> >>>>>> expose and develop them.
> >>>>>>
> >>>>>> BTW, I encourage everyone to stop speaking of "stops" and "contrast
> >>>> range"
> >>>>>> -- much better to identify clearly what you mean and speak of
> >>>> "exposure
> >>>>>> scale" ("ES") and "density range" ("DR"), to make sure we are always
> >>>> keeping
> >>>>>> the distinction in mind.  On this, see my message of 11 Oct 2009, in
> >>>> the
> >>>>>> archive.  For example, while the ES of traditional Pt is around 2.1
> to
> >>>> 2.4
> >>>>>> (and, therefore, a negative that produces a full-scale Pt print will
> >>>> have
> >>>> a
> >>>>>> DR of 2.1 to 2.4), the full-scale DR of the Pt print itself is much
> >>>> lower
> >>>> --
> >>>>>> only 1.4 to 1.7 (the latter only with heroic efforts).
> >>>>>>
> >>>>>> ==========
> >>>>>>
> >>>>>> There are two things at work here: (i) matching the negative density
> >>>> range
> >>>>>>> ("DR") to the printing exposure scale ("ES"); and (ii) the
> character
> >>>> of
> >>>> the
> >>>>>>> exposure scale, however long or short it is.  If the DR of your
> negs
> >>>> is
> >>>> too
> >>>>>>> short to match the printing ES, you'll get low-contrast prints with
> >>>> murky
> >>>>>>> (but not very deep) shadows and/or fogged-looking highlights.  But
> >>>> even
> >>>> if
> >>>>>>> the negs have the right DR for the process, the characteristic
> curve
> >>>> of
> >>>> the
> >>>>>>> printing process may be ugly.
> >>>>>>>
> >>>>>>> The standard long-scale Pt process has a very, very long linear
> scale
> >>>>>>> with symmetrical, gently rounded toe and shoulder, typically
> printing
> >>>> the
> >>>>>>> whole step wedge with some scale left over.  Therefore, you need to
> >>>> use
> >>>>>>> negatives with a very high DR to obtain all of the available print
> >>>> zones
> >>>>>>> with this process.  Photographers have not typically made negatives
> >>>> this
> >>>>>>> "bulletproof" since the late 19th Century, so folks have tried a
> >>>> number
> >>>> of
> >>>>>>> different methods to shorten the Pt exposure scale (adding
> >>>> dichromates,
> >>>>>>> hydrogen peroxide, etc., etc.).  These tricks shorten the exposure
> >>>> scale
> >>>> by
> >>>>>>> raising the threshold exposure -- not really a very promising way
> to
> >>>> go
> >>>>>>> about it.  Anybody who has done serious sensitometry with the
> process
> >>>> has
> >>>>>>> seen the ugly characteristic curves the short-scale versions of the
> >>>> Pt
> >>>>>>> process produce.  I have yet to see prints made using any
> short-scale
> >>>> Pt
> >>>>>>> process that came close to the look of "real" (long-scale) Pt
> prints.
> >>>>>>> Unfortunately, so many workers are using the short-scale processes
> >>>> now
> >>>> that
> >>>>>>> many people don't even know what a good Pt print is supposed to
> look
> >>>> like.
> >>>>>>>
> >>>>>>> I commend to you an experiment:  Make some in-camera negatives with
> a
> >>>> DR
> >>>>>>> above 2.1 (try to hit 2.4 for starters), and print them using the
> >>>> standard
> >>>>>>> full-scale Pt process.  I bet you never go back to digi-neg Pt
> >>>> printing
> >>>>>>> again, and depending on how big you think prints need to be, that
> you
> >>>>>>> acquire one or more LARGE format cameras or learn to make good
> >>>> enlarged
> >>>>>>> negatives in the darkroom (not so easy now that slow,
> blue-sensitive
> >>>> copy
> >>>>>>> films are long gone).  If you have no option besides digital, have
> a
> >>>> service
> >>>>>>> bureau make some 2.4 DR negatives with an imagesetter using your
> >>>> files.
> >>>>>>>
> >>>>>>
> >>>>>> ==========
> >>>>>>
> >>>>>> Think of it as mapping.  The scene you photograph has a certain
> range
> >>>> of
> >>>>>>> luminance values.  You want to translate, or "map," these luminance
> >>>> values
> >>>>>>> to useful negative densities, which can in turn be mapped to the
> >>>> available
> >>>>>>> reflection densities of your chosen printing medium.
> >>>>>>>
> >>>>>>> To do this, we start with the exposure scale ("ES") of the printing
> >>>>>>> medium.  Using calibrated step wedges, we see what range of
> exposures
> >>>> gives
> >>>>>>> the full range of printed tones the medium is capable of producing
> --
> >>>> any
> >>>>>>> more exposure is indistinguishable from the blackest tone, and any
> >>>> less
> >>>>>>> exposure is indistinguishable from the lightest tone (paper white,
> or
> >>>> close
> >>>>>>> to it).  Now, if we want the full range of tones the process is
> >>>> capable
> >>>> of
> >>>>>>> producing to be represented in our print [which may not always be
> the
> >>>> case],
> >>>>>>> we know that our negative must have a density range ("DR") equal to
> >>>> the
> >>>>>>> printing medium's ES.  So, we arrange to translate the luminance
> >>>> values
> >>>> in
> >>>>>>> the scene to the particular negative densities that will produce
> the
> >>>> print
> >>>>>>> tones we want to represent each scene luminance value.
> >>>>>>>
> >>>>>>> Not so long ago, we did this by adjusting our exposure and film
> >>>>>>> development, and then perhaps reducing or intensifying the negative
> >>>> or
> >>>>>>> masking it for printing, and finally by dodging and burning as we
> >>>> printed.
> >>>>>>> It sometimes took all that, because we have to condense or compress
> >>>> the
> >>>>>>> 1,000,000:1 luminance range of the scene we photographed (this is
> >>>> about
> >>>>>>> normal for a sunlit scene) down to the 100:1 (or less) density
> range
> >>>> that a
> >>>>>>> print can reproduce.
> >>>>>>>
> >>>>>>> These days, people who print digitally can use Photoshop to adjust
> >>>> the
> >>>>>>> mapping from the as-captured (or as-scanned) image file to the
> >>>> negative
> >>>> that
> >>>>>>> will be used to make the print.  This is much easier, and also much
> >>>> more
> >>>>>>> flexible, than doing it chemically or with masks.  However, the
> goal
> >>>> is
> >>>> the
> >>>>>>> same -- to translate or map certain luminance values in the scene
> to
> >>>> the
> >>>>>>> desired print density values, using the negative as an
> intermediary.
> >>>>>>> Applying curves is how we do this.  It's fundamentally the same as
> >>>> using
> >>>>>>> the Photoshop tonal controls (levels, brightness/contrast,
> whatever)
> >>>> to
> >>>>>>> adjust a digital capture for the desired print values (i.e., if you
> >>>> are
> >>>> just
> >>>>>>> printing digital images on paper), with two added wrinkles: (i) you
> >>>> have
> >>>> to
> >>>>>>> understand how the characteristic curve of the printing process
> >>>> responds
> >>>> to
> >>>>>>> the negative values, and (ii) you have to be able to imagine how to
> >>>> "do
> >>>> it
> >>>>>>> in reverse" since you are working on a negative -- if you want the
> >>>> shadows
> >>>>>>> to have more contrast in the print, you have to increase the
> contrast
> >>>> in
> >>>> the
> >>>>>>> lightest parts of the negative.
> >>>>>>>
> >>>>>>> In theory, you can map any scene luminance value (or digital
> >>>>>>> representation of a scene luminance value) to any available print
> >>>> tone
> >>>> (with
> >>>>>>> the caveat that the curve should be monotonic -- never reversing
> >>>> slope
> >>>> --
> >>>>>>> unless you are after special effects reminiscent of the Sabattier
> >>>> effect).
> >>>>>>> In my view, there is no substitute for learning enough
> >>>>>>> sensitometry/densitometry to really understand how the mapping
> works,
> >>>> and
> >>>>>>> then to test your processes to see how they distort the mapping so
> >>>> you
> >>>> can
> >>>>>>> correct for it.  It's not very difficult, and once it is mastered
> you
> >>>> will
> >>>>>>> truly have the chops to get what you want out of your photographs.
> >>>>>>>
> >>>>>>> So, all that said, back to curves destroying negative content.
> >>>> Mapping
> >>>>>>> is mapping -- the person who wants to represent the surface of the
> >>>> earth
> >>>> on
> >>>>>>> a flat surface has choices to make, because there is no way to
> >>>> linearly
> >>>>>>> reproduce the surface of a sphere on a flat surface.  And as we
> >>>> learned
> >>>> in
> >>>>>>> grade school, cartographers have come up with hundreds of different
> >>>> ways
> >>>> to
> >>>>>>> do it, each one good for some particular task.  If you want to be
> >>>> able
> >>>> to
> >>>>>>> visualize comparative land areas, you use a different projection
> than
> >>>> if
> >>>> you
> >>>>>>> want to determine bearings from one place to another.  The same is
> >>>> true
> >>>> for
> >>>>>>> mapping tonal values in photography.  So, the "right" curve is the
> >>>> one
> >>>> that
> >>>>>>> produces the results you want -- i.e., the one that maps the scene
> >>>> luminance
> >>>>>>> values to the print densities you want.  In general, one way I'd
> >>>> advise
> >>>>>>> folks NOT to do this is to copy someone else's curve "because
> you're
> >>>> using
> >>>>>>> the same process."  No two people ever use the "same" alt process,
> >>>> because
> >>>>>>> there are way too many variables to control.  And no two monitors
> are
> >>>> the
> >>>>>>> same, or scanners, or printers, or Pt "emulsions," or coating
> >>>> techniques, or
> >>>>>>> anything else you use to make prints.  So, the only way to end up
> >>>> with a
> >>>>>>> useful curve for your process flow is to test and figure it out for
> >>>>>>> yourself.
> >>>>>>>
> >>>>>>> Generally, one would like to calibrate one's monitor, then build a
> >>>> curve
> >>>>>>> for each printing process one uses so one can just adjust the image
> >>>> on
> >>>> the
> >>>>>>> monitor (as a positive), then let the computer figure out what
> >>>> negative
> >>>>>>> densities are required to map the monitor view to the final print
> >>>> (though
> >>>>>>> once again, the monitor has a considerably greater luminance range
> >>>> than
> >>>> a
> >>>>>>> print has density range, so it will be a "rendition" of the monitor
> >>>> image,
> >>>>>>> not a literal copy).  Only you can build such a curve, after doing
> >>>> the
> >>>>>>> sensitometry/densitometry on your equipment and printing processes.
> >>>> There
> >>>>>>> are aids available, but IMO one is much better off gaining an
> >>>> understanding
> >>>>>>> of the fundamentals and just doing it -- just as people who really
> >>>>>>> understood what they were doing always got better results than
> people
> >>>> who
> >>>>>>> "learned" the "zone" system by rote.
> >>>>>>>
> >>>>>>> So, if you have a curve that really does translate (transliterate
> ??)
> >>>>>>> from your monitor to your prints, great -- it is not destroying
> >>>> anything,
> >>>>>>> but rather helping you to map values from your digital image file
> to
> >>>> the
> >>>>>>> final print, thereby allowing you to do your image adjustment by
> eye
> >>>> rather
> >>>>>>> than by figuring.  But if your curve doesn't produce prints that
> are
> >>>>>>> pleasingly rendered based on the screen image, you need to change
> >>>> something.
> >>>>>>> You can futz around with the process to try to match it to the
> curve
> >>>> you
> >>>>>>> have, but that's the hard way (and you may well not ever find a
> >>>> variation
> >>>>>>> that works as you'd like).  Better to adjust your printing process
> >>>> until
> >>>> you
> >>>>>>> get the most linear scale you can (for reasons I won't go into
> here,
> >>>> having
> >>>>>>> to do with producing the smoothest tonal range), then developing a
> >>>> curve
> >>>>>>> that translates from your monitor to your prints.
> >>>>>>>
> >>>>>>> The problem with the "short-scale" versions of Pt is that they have
> >>>> much
> >>>>>>> less linear tonal ranges than long-scale Pt.  You can successfully
> >>>> map
> >>>> this,
> >>>>>>> if you work at it, and thereby get correct overall tonal rendering
> by
> >>>> using
> >>>>>>> a curve that compensates for the nonlinearity.  However, you still
> >>>> won't
> >>>> get
> >>>>>>> the smooth transitions that long-scale Pt can produce.  And since
> the
> >>>>>>> gorgeous tonal rendering is the real draw of Pt in the first place,
> >>>> why
> >>>>>>> settle for something less just because one would prefer to avoid
> >>>> dealing
> >>>>>>> with how to make digital negatives of sufficient DR?  Particularly
> >>>> given
> >>>> the
> >>>>>>> cost of the Pt process, I just can't see why one wouldn't use it to
> >>>> its
> >>>> full
> >>>>>>> advantage -- which IMO requires using the long-scale process.
> >>>>>>>
> >>>>>>
> >>>>>>
> >>>>>> Best regards,
> >>>>>>
> >>>>>> etienne
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>> ______________________________**_________________
> >>>>>> Alt-photo-process-list |
> >>>> http://altphotolist.org/**listinfo<http://altphotolist.org/listinfo>
> >>>>>>
> >>>>>
> >>>>>
> >>>> _______________________________________________
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> >>>>
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> >>>
> >>>
> >>
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