[Alt-photo] Christopher James - terminology question

Keith Schreiber keith at jkschreiber.com
Fri Oct 27 20:10:30 UTC 2017


The Ware formula has a longer tonal range (lower contrast) by 2-3 stops, and smoother (less gritty) tones as well. Exposure time is significantly faster than the classic Herschel method using ferric ammonium citrate. Paper is a huge variable with cyanotype. As is consistency in processing - longer wash reduces density especially in the highlights and mid-tones. 

When you are talking about step-tablets, it is useful to know whether you are talking about a digital step-tablet or an analog one such as those made by Stouffer. In my opinion, it is very useful to get acquainted with any process using a Stouffer step-tablet before even thinking about digital negatives. You will learn more from this about the characteristics of the process than from all the trial and error shooting in the dark premature messing around with digital negs in the world. I like the 4x5 21-step (TP 4x5) rather than the strip type. 

A stop is a known quantity. One stop equals 0.30 density units. This does not change. On an analog step tablet with 21-steps, each step is 0.15, so 2 steps equals 1 stop. On a 31-step, each step equals 0.10, so 3 steps equals 1 stop. 

If you really want to get a handle on steps and stops and practical photographic sensitometry, I highly recommend "Beyond The Zone System" by Phil Davis. 

The beauty of digital negatives is that we can tailor them to the whatever process (and variables of the process) that we are using. Once you have figured out the correct minimum exposure time to achieve maximum density, a full-tonal scale can be achieved via a variety of methods. I haven't used the method you are using, but I have no doubt it is quite capable. But you really have to figure out all of your process parameters BEFORE starting to work with digital negatives because a change in anything will require recalibrating the negative.

I've been printing mostly platinum/palladium for over 25 years. I've recently started doing cyanotype with a student new to alternative processes and am surprised to find just how much of a moving target it is compared to Pt/Pd. And we haven't even started toning yet!


Keith Schreiber

> On Oct 27, 2017, at 1:18 PM, John Isner via Alt-photo-process-list <alt-photo-process-list at lists.altphotolist.org> wrote:
> I bought the Ware "New Cyanotype" formula but have not tried it yet.  I am
> using the standard A + B with the variations you mentioned.  These reduce
> contrast in midtones and highlights but leave the shadows blocked.  Does
> the Ware formula unblock the shadows?
> On Fri, Oct 27, 2017 at 11:54 AM, Don Bryant <donsbryant at gmail.com> wrote:
>> John,
>> As James points out, over all contrast can be reduced by adding water to
>> the
>> A+B solution using the traditional cyanotype receipt. If your shadows are
>> blocked it is doubtful that any chemical adjustment will show detail and
>> reduce contrast.
>> One can also vary the A to B proportions to decrease contrast.
>> Have you tried the Ware formula?
>> Don Bryant
>> -----Original Message-----
>> From: Alt-photo-process-list
>> [mailto:alt-photo-process-list-bounces at lists.altphotolist.org] On Behalf
>> Of
>> John Isner via Alt-photo-process-list
>> Sent: Friday, October 27, 2017 2:08 PM
>> To: David Hatton
>> Cc: The alternative photographic processes mailing list
>> Subject: Re: [Alt-photo] Christopher James - terminology question
>> I think I understand now.  In quoting James, I misread "steps" as "stops."
>> More steps means more intermediate tones visible between any given pair of
>> tones in a step wedge, while fewer steps means more abrupt change in
>> tonality, hence higher contrast.
>> In my initial experiments with cyanotype, I got high contrast in the
>> shadows and moderate contrast in the midtones and highlights.  By altering
>> the process (e.g., developing in acid + water instead of just plain water,
>> or adding a few drops of distilled water to the sensitizer), I was able to
>> lower contrast in the midtones and highlights, but the shadows remained
>> stubbornly high contrast.  Furthermore, the transition from shadows to
>> midtones occurs fairly abruptly.
>> Is it possible to lower contrast in the shadows without increasing contrast
>> in the midtones and highlights?  In other words, is it possible to lower
>> contrast across the entire spectrum?  Or is contrast a zero-sum game, as it
>> is with a Curves adjustment in Photoshop (Curves let you push contrast
>> around but not eliminate it).
>> On Thu, Oct 26, 2017 at 7:28 AM, David Hatton <davidhatton at totalise.co.uk>
>> wrote:
>>> A long tonal range ie more tones visible is low contrast whereas a short
>>> tonal range  ie less tones visible is high contrast
>>> David
>>> On Thu, Oct 26, 2017 at 2:16 PM, John Isner via Alt-photo-process-list <
>>> alt-photo-process-list at lists.altphotolist.org> wrote:
>>>> I am new to alternative process, having come from a digital photography
>>>> background (no darkroom experience).  This is my second post to the
>>>> mailing
>>>> list.
>>>> I'm struggling to understand two terms that Christopher James repeatedly
>>>> mentions in his book, but never explicitly defines: contrast and tonal
>>>> range.  For example, on page 185 in the cyanotype chapter, he says that
>>>> using a particular developer chemistry will give "a significant increase
>>>> in
>>>> the range of values (2 to 4 stops) but a decrease in contrast."
>>>> My understanding of contrast and tonal range is based on the histogram
>> in
>>>> digital photography:   An image with a large tonal range has a wide
>>>> histogram, that is, large "distance" between the darkest and lightest
>>>> tone,
>>>> while a high contrast image has relatively few midtones.  To my mind,
>> the
>>>> alt process equivalent of the histogram is a printed sample of a step
>>>> wedge
>>>> with 256 brightness levels from black to white.  When James says a
>>>> "decrease in contrast," I interpret this to mean that the tones bunch up
>>>> at
>>>> the dark and the light ends of the step wedge, with very few tones in
>>>> between.  That makes sense to me.  However when he says "a significant
>>>> increase in range of values (2 to 4 stops) I'm confused.  Since you
>> can't
>>>> get any whiter than paper white, an "increase in range of values" could
>>>> only mean one thing: the darkest tone gets darker!   I suspect this is
>> NOT
>>>> what he means.
>>>> Can someone help me understand this?
>>>> Thanks,
>>>> John
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