[alt-photo] Re: salt printing - integrated density

KISS BOB bobkiss at caribsurf.com
Sun Aug 26 12:03:25 GMT 2012 

Way back in the early 70s at RIT we used Fourier 
transforms to create OTF (optical transfer function) 
curves of lenses and MTF (modulation TF) curves of films 
and multiple optical systems.  We did the same thing 
(removing any repeating patterns) from images but much 
more slowly using analog optics and spatial filters. 
 Fourier transform has tons of applications in optical, 
electronic, audio and communications systems.  When we 
tried to create Fourier transform programs (remember, 
early 70s...Fortran IV and all that!) it GOBBLED what 
little RAM and hard drive we had.  Now that 4 gigs of ram 
is standard and a 2 Terabyte hard drive can be had for 
less than the cost of an automobile tire, I have been 
wondering when someone would digitize it in a form 
available for us mere mortals.  This is wonderful!  Like 
seeing an old friend who is young again!


On Sun, 26 Aug 2012 00:25:20 -0400
  clay harmon's personal website email account 
<clay at clayharmon.com> wrote:
> ImageJ is an amazing program. I had a friend ask me to 
>to scan and recover an image of his deceased wife which 
>happened to be printed on the 'silk' textured paper that 
>was popular in the seventies. I used ImageJ to do a 
>Fourier transform on each of the RGB channels, edit out 
>the pattern in F-K space, and then do an inverse Fourier 
>transform on the channels and reassemble in photoshop. 
>Worked perfectly to get rid of the pattern noise with 
>almost no loss of the actual image. And it's free!
> 
> -Clay
> 
> Sent using 100% all-natural biodynamic electrons
> 
> On Aug 25, 2012, at 6:02 PM, "Gordon J. Holtslander" 
><gjh at shaw.ca> wrote:
> 
>> Hi:
>> 
>> It may be possible to analyze the image/negative to 
>>predict the amount of reduced silver is produced in a 
>>salt print.
>> 
>> I used the public domain Scientific Image Analysis 
>>Program ImageJ a great deal.
>> 
>> One of the measurements ImageJ will perform is the 
>>integrated density of an image.
>> 
>> From http://rsbweb.nih.gov/ij/docs/menus/analyze.html
>> 
>>  Integrated Density - Calculates and displays two 
>>values: "IntDen" (the product of Area and Mean Gray 
>>Value) and "RawIntDen" (the sum of the values of the 
>>pixels in the image or selection).
>> 
>> RawIntGen measures the sum of values of each pixel in an 
>>image (or selected region of an image)
>> 
>> This value would be equivalent to the summing the 
>>density of each pixel in the image used to produce the 
>>print.
>> 
>> Since the density of each "pixel" in a negative would 
>>determine how much metallic silver is produced in a salt 
>>print, the RawIntGen value would be strongly correlated 
>>with the total amount of reduced silver in a salt print.
>> 
>> Could this value be used to predict the total amount of 
>>reduced silver in a salt print
>> 
>> ImageJ is support by the National Institutes of Health
>> 
>> ImageJ is available for Windows, Mac, linux - anything 
>>that will run Java
>> http://rsbweb.nih.gov/ij/download.html
>> 
>> More info on ImageJ http://rsbweb.nih.gov/ij/index.html
>> Users guide http://rsbweb.nih.gov/ij/docs/user-guide.pdf
>> ImageJ
>> 
>> Gord
>> 
>> On 8/24/2012 6:23 PM, Christina Anderson wrote:
>>> Ohmagosh. I see. That is VERY interesting and makes 
>>>total sense, that the amount of reduced silver in the 
>>>image depending on the shadows or highlights of that 
>>>particular image, would influence color. Very neat. Not 
>>>read that in the literature.
>>> Chris
>>> 
>>> 
>>>> Not quite. The affect on color is relative to how light 
>>>>or
>>>> dark the image is... how much silver is held in the 
>>>>paper to form the
>>>> image... that's the killer for me. No matter how exact I 
>>>>measure the
>>>> chemistry, the amount of silver that forms each image 
>>>>will affect the
>>>> final color. I'm conjuring up a plan to use a histogram 
>>>>to guide my
>>>> tweaking... haven't gotten down to designing the 
>>>>information transfer to
>>>> a volume or time variable yet and it might be a bogus 
>>>>idea... too soon
>>>> to tell.
>>>> 
>>>> I'm measuring with a 10ml syringe.... exactly 4ml per 
>>>>12x15
>>>> sheet. I might be off a drop or so, but not much. I 
>>>>could try measuring
>>>> drops as a means to reduce another variable I suppose.
>>>> 
>>>> I know the
>>>> table you're referring too with the speedier salts 
>>>>listed against their
>>>> contrast. In my experience the isn't much difference in 
>>>>contrast, only
>>>> speed and final color.
>>>> 
>>>> One last note, the final color can't be judged
>>>> before the print is totally dry. That tends to slow down 
>>>>these tests.
>>>> Humidity is pretty constant since I have AC in my 
>>>>darkroom, but since
>>>> it's MI... it's always high.. 55-65%
>>>> 
>>>> ~Darryl
>>>> 
>>>> On 2012-08-23 12:28,
>>>> Christina Anderson wrote:
>>>> 
>>>>> Darryl,
>>>>> 
>>>>> Can I quote you :)? I am
>>>> thrilled to find someone really doing salt on this list, 
>>>>separate from
>>>> albumen anyway...
>>>>> 
>>>>> Do you find salt a longer tonal range than
>>>> pt/pd?
>>>>> 
>>>>> What is your choice of fixing bath and time?
>>>>> 
>>>>> So the
>>>> amount of silver nitrate influences color...you would 
>>>>have to be,
>>>> therefore, exact with your drop-to-sq.-inch count to get 
>>>>similar color,
>>>> right?
>>>>> 
>>>>> One thing I am puzzling with is Young's use of the word
>>>> "contrast." If a certain solution is faster in exposure, 
>>>>she then
>>>> equates it with lower contrast. Now, I could be the one 
>>>>confused but I
>>>> have always understood contrast to be separate from 
>>>>exposure. Once
>>>> maximum black and maximum white are achieved, the number 
>>>>of steps
>>>> between the two is either fewer (more contrasty) or 
>>>>greater (less
>>>> contrasty) but if comparing faster and slower solutions 
>>>>this gives a
>>>> false read.
>>>>> 
>>>>> That would be like, in the B&W darkroom, exposing a
>>>> grade 0 paper and a grade 5 paper the same time and 
>>>>comparing the
>>>> papers' contrast.
>>>>> 
>>>>> I would first get the standard printing time
>>>> (SPT) and then compare the number of steps. But I could 
>>>>totally have it
>>>> wrong all these years. PLEASE correct me??
>>>>> 
>>>>> I have the PDF, and just
>>>> ordered the book, but thanks for the offer. I wanted to 
>>>>see the step
>>>> wedges in print.
>>>>> 
>>>>> I do like her clear method of writing and
>>>> testing.
>>>>> 
>>>>> An off-lister suggested Ware's article on salt, too.
>>>>> 
>>>>> 
>>>> OH, one other thing. I was able to see Panera and 
>>>>Hajicek's giant salt
>>>> print photograms done in the sunlight at F295 a few 
>>>>years back. Now THEY
>>>> were stunning. And of course Dan Estabrook's work is a 
>>>>favorite of mine.
>>>> Jesseca Ferguson as well.
>>>>> Chris
>>>>> 
>>>>> Christina Z. Anderson
>>>>> 
>>>> christinaZanderson.com
>>>>> 
>>>>> On Aug 23, 2012, at 12:09 PM, Darryl Baird
>>>> wrote:
>>>>> 
>>>>>> Chris, I spent a good portion of this year working on
>>>> getting salt printing "down" and I've discovered there 
>>>>isn't a single
>>>> formula published that works completely as "advertised" 
>>>>in any of the
>>>> sources you've just cited. Young's work is, by far, the 
>>>>most complete,
>>>> yet there are gaps or things a little glossed over. I 
>>>>revised Young's
>>>> formula (using Potassium Chloride) with a couple of 
>>>>additives in the
>>>> sizing, and a minor modification in the hypo stage. I 
>>>>was happy...
>>>> notice the past tense. Young published her research as a 
>>>>dissertation
>>>> first, then revised it into the pdf "manual." I have 
>>>>both if you'd like
>>>> a copy of the former. One of the latest finds (for me) 
>>>>is a statement by
>>>> Reilly about the color also being determined by the 
>>>>amount of silver
>>>> used (retained in the paper) in making any image. It 
>>>>made perfect sense
>>>> that the final amount of silver within the image being 
>>>>toned would have
>>>> an affect on the final color. This one little "detail" 
>>>>sent me over the
>>>> top considering I want EVERY print I produce in a 
>>>>portfolio to match in
>>>> color. So, my next challenge is to manage a method to 
>>>>estimate the
>>>> amount of total silver present and adjust either my 
>>>>toning time or
>>>> volume for each image. PITA I'd already resorted to a 
>>>>single-shot
>>>> solution for each step, never reusing chemistry in order 
>>>>to narrow or
>>>> eliminate the color variables from each.
>>>>>> 
>>>>>>> From Reilly, Chapter
>>>> 8:
>>>>>> Toning "Among the factors which influence the outcome of 
>>>>>>the
>>>> toning operation are the pH of the binder (gelatin, 
>>>>arrowroot, albumen,
>>>> etc.) materials used, the pH of the silver solution, 
>>>>**the amount of
>>>> silver deposited to form the image,** the thoroughness 
>>>>of the initial
>>>> wash in processing, the pH of the toning solution, the 
>>>>presence of other
>>>> substances in the toning solution, the strength of the 
>>>>gold solution,
>>>> its temperature, its age, and the time of immersion of 
>>>>the print." Steve
>>>> Achell has some helpful advice in this document... it 
>>>>was helpful in
>>>> some of my formula changes.
>>>> http://steveanchell.com/index.php?option=com_content&view=article&id=34%3Asalted-paper&catid=15%3Aoutput-darkroom-and-lightroom&Itemid=39
>>>> [1] and
>>>> http://www.alternativephotography.com/wp/pop-printing-out-process/printing-out-processes
>>>> [2]I'm also going to start a new printing test using 
>>>>fumed silica.
>>>> Darryl On 2012-08-23 09:50, Christina Anderson wrote:
>>>>>> 
>>>>>>> Dear
>>>>>> 
>>>> All, I noticed last night when googling it that it is 
>>>>available on
>>>> Amazon here and also on the alternativephotography.com 
>>>>website
>>>> here:http://www.alternativephotography.com/wp/processes/saltprints/the-salt-print-m
>>>>>> 
>>>> 
>>>>>>> lt-Print-Manual-Ellie-Young/dp/144528328XFor some 
>>>>>>>reason,
>>>>>> ow
>>>> how long I have had it, I have a PDF of it from the web, 
>>>>so at one point
>>>> it was free. In any case, I want to give credit to her 
>>>>for her research
>>>> and did buy the book (I can't stand reading PDFs). It 
>>>>seems between
>>>> Reilly, James' chapter on salt in his book, and Young's 
>>>>book there isn't
>>>> too much other current literature on the process, unless 
>>>>it is just
>>>> lumped under albumen which is quite popular. OH and Ed 
>>>>Buffaloe's
>>>> article on unblinkingeye.com which BTW includes a CASEIN 
>>>>sizing for the
>>>> salt print I am dying to experiment with, because it 
>>>>would be matte like
>>>> casein is, and like Reilly talks about
>>>>>> 
>>>>>>> 
>>> 
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>> 
>> 
>> -- 
>> Gordon J. Holtslander
>> gjh at shaw.ca
>> _______________________________________________
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