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

[Francesco Fragomeni]

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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>