Re: Back-exposing on plastic (was: Re: Gum transfer

Terry,

are you saying what I think you are saying, you can do a gum print like you say below in a single exposure.? Even if you say you need more then one exposure to do it like you said below and if Katherine is right and it is possible to get 10-12 steps to show with the best gum emultion one can make, then there is absolutely no reason in this world we can't make an excellent gum print in a single exposure and I'm not even using the curse word here. If as you say these guy did it in the 1900 why is everyone saying you can't make a good or better an excellent gum print in a single exposure even on this list, in fact some even tried to ridicule even the thought of it. You are absolutely right, I've been missing the point all along about gum printing. Did you know some folks are making up to 13-15 exposures gum prints.

As for making negative for platimum, something doesn't add up, correct me if I'm wrong and I may very well be, an in camera negative as to be carefully (precicely) exposed and develop for each scene because the lighting condition change all the time and everywhere and also it must mach the print process like a glove. Now if you do that for your patinum work (negs), I'm not surprised to ear your in camera negatives make better print then digi-negs. What I find surprising, knowing the rigor and control one must have to secure perfectly matching negatives in practice, is that you seem to do reach this perfect match let just say frequently. Even the most sophisticated digital cameras can't do it all the time and they never forget anything, the exposure is time to the millisecond, etc. I was never satisfied with the decicion I made at a scene while taking the shot(s) even with my D70 I always did some fine tuning on the original before printing it.

Today, I've come to the following approach, when I go out and take shots, I try to capture on film as much information (data) as possible or should I say as much as my scanner can read with minimal distortion and you would be right to say there maybe lots of info my scanner will leave out or not be able to read if you prefer. If I need to manipulate, numerically that is, my negatives and I always do, ok I'll admit I'm loosy at making perfect negative, I consistantly miss the target, I have a good excuse I think, I'm only human. For me, trowing out my digital camera is the best move I ever did, surprised, don't be no digital camera can capture an image like a large format camera can especially if you want to print large as well. This may very well not be true for long but I don't care and when I say I don't care I really mean it, soon I'll try out my 4 pinhole cameras cardboard box really and if I like what I see I'll probably put aside my 645 for while. I know I'm crazy I'm not seeking the perfect negative anymore, cristal clear image, depth of field, etc all of these mean absolutely nothing if the image doesn't make you physically react when you see it, yes my goal and my only goal now is to capture the magic of light, will I never be able to do it is another story. Yes this is the same guy who claim he can juggle with number and make them do what he wants, this new concept I'm working on will be able to do exactly what I claim pixel by pixel without any curve(s), compression or expension of any kind and if there is enough distinct densities a printer can produce to translate a 16 bits black and white digital image into 24 bits equivalent density triplets then may be you'll find pretty soon it is not worth the trouble to carry a big 8x10 around anymore because it will no longer make a difference unless of course they idea is to enlarge the 8x10 negative beyond the capabalities of smaller negatives.

Regards
Yves
 
 

----- Original Message -----
  From: TERRYAKING@aol.com
  To: alt-photo-process-l@usask.ca
  Sent: Wednesday, May 03, 2006 4:18 AM
  Subject: Re: Back-exposing on plastic (was: Re: Gum transfer

  Yves

  You are still missing the point.

  Gum printing is so flexible that you do not need fancy numbers. Making a negative on 90 gsm Fabriabo Liscia straight from an inverted and flipped image that looks good on the screen, will make a perfectly good gum print. i am afraid that Sandy has rather distorted what I have said. Curves did confuse the issue in this context as it would have been easier to have made the point, as I did, by making the analogy with the stretching of tones in a silver gelatine print from a weak negative, ie on hard paper..

  Of course you need to adjust the curve for platinum printing when using digital negatives.. I have had a very useful discussion on these matters with Dan at 0230 in the Macdonalds at Gatwick airport..

  i have my digital cameras and my scanners and I use them. I also use wet processing. it just so happens that I get a great deal of pleasure, on many levels, from taking photographs for platinum printing on my 10 x 8 camera, exposing and developing those negatives to meet a density range for platinum ( a platinum curve !) It is also my view that these special in camera negatives produce better platinum prints on a side by side comparison with prints made from digital negatives.. (You may care to have a look at my articles in View Camera).

  Puyo and Demarchy are two of the greatest gum printers . Please have a look at their work in the archives of the Societee Francaise de Photographie in Paris and read their articles in the annuals of the Society around 1900.. Also have a word with your compatriot Christian Nze who contributes to the discussions on Dick Sullivan's discussion list which is accessible through the B & S web site. Dick is quite strict in ensuring a high level of discussion. The point is that Demarchy and Puyo produced gum prints with an apparent large range of tone without multiple printing. I have the annuals for the years concerned. I meant to read them last night, I have set, but got involved in some research on Ruskin's use of the daguerreotype instead.

  All the best

  Terry

  In a message dated 3/5/06 8:29:50 am, gauvreau-yves@sympatico.ca writes:

    Terry,

    you may be right, I thought I read posts by you quite a few times where you kind of find digi-negs a waiste of time. Below you obviously don't say this again and you basically agree with the concept of matching a negative with the process response. The way this is done, wheter the traditional approach (wet processing) or the digital approach (curves) is irrelevent, it could be much easier and much less costly to play with numbers then with chemicals but that's another story.

    in an earlier message late last night you wrote this: "It is you who has fallen into the trap of allowing yourself to be blinded by this obsession with curves"

    and before that, to me you wrote this :

    "This was an attempt to explain the inexplicable.

    The curves are not only an unnecessary complication but they also confuse the issue. Expressed without reference to curves, all this is saying is that there is a loss of gradation if the density of the print is 'stretched'.

    Incidentally, how would you explain Puyo's technique in making single coat gum prints ?

    Furthermore, if you think that you are not getting your point over in English, why not make the point in French too ?"

    I could go on but it would be pointless IMHO. I don't know this person, Puyo's and there are a lot more things I don't know about or don't understand but if I would have a little bit of context on what he does I'm sure if not me, someone else could give you all the response you want and maybe much more.

    But if I was satisfied with a relatively low Dmax, say the 1.2 as Sandy said earlier and the relatively flat response obtainable from a single coat gum print. I would approach the problem this way, first I would make enough gum emultion such that can make quite a few test and prints without changing anything to my recipe. One of my first test would be to find how much exposure I need to secure the target Dmax. The next test would be to print a standard step tablet to learn the response of this particular emultion/paper combo if not already done simultaniously in the exposure test. Now I don't presuppose a linear response would suit the image just like that and I would use a negative feedback approach to find what kind of curve I will use for this image on this particular emultion. The way this would be done is say I print a negative where the densities progress in a strait line from min to max and to compare it with a different version, I could begin by increasing the contrast in the highlights, if I don't like that I could try the same with the shadow and so on until I'm satisfied I've made the finest print I could.

    Now I claimed not long ago that I could manipulate the negative values to produce any tones or densities I wanted from the min to the max a specific emultion can produce with proper exposure but I didn't say how and since then I've find out quite a few things. To make things as short as possible the concept is this: An (R,G,B) triplet is normaly viewed as a color, from now on, lets view it as an effective UV density.

    We all know a specific density on a properly match negative will cause a distinct exposure to be effectively applied locally under the area(s) where we find those specific densities and this will cause some specific tone to be produce. Now say I can choose from 16 million such triplets each producing a specific density value but not all triplet produce a distinct density value or the other way around it is possible a specific density can be obtain using different triplets. If I would choose from this large pool of triplets a bunch, such that each of them produce the tone that I want, this would give us an incredible number of ways to print a gum emultion in a single exposure. There is however a BUG with this idea, no it is not the number of distinct density that can be produce but rather the software we are using doesn't allow us to change individual pixel value one at a time, it's crazy but they where not design that way. But thankfully, there are workaround and it wont be long before someone gets it, if you see what I mean.

    Regards

    Yves

    PS. There are many many details I left out but be assured, we wont need to involve the NASA.

    ----- Original Message -----

    From: TERRYAKING@aol.com

    To: alt-photo-process-L@usask.ca

    Sent: Tuesday, May 02, 2006 8:12 PM

    Subject: Re: Back-exposing on plastic (was: Re: Gum transfer

    Yves

    There may be a language difficulty here as I do not think that you have understood the relationships.

    Each of these processes has a maximum density range that does not change. It is a constant.

    This is chemical and physical constant independent of how one makes one's negatives, Photoshop or what is done in the printing industry.

    Of course, if one has any sense, one makes one's negatives, whether digital or otherwise, to suit what each processes will accept..

    As a rider to the above, this does not mean that one has to expose a different negative for every process. Different scenes call for different processes. while negatives can be adapted to suit different processes.

    Terry

    In a message dated 3/5/06 12:37:44 am, gauvreau-yves@sympatico.ca writes:

    Terry,

    your position on the pertinence of manipulating the distribution of values on a negative in order to produce a better match between the neg and the properties of a process dependent print is well known. I don't critic your position, I just don't understand why an experience guy like you who probably as work very hard to get is negatives to match as much as possible the exposure scale and other characteristics of his print process material. Even assuming you never did made any special effort of any kind ie. use and develop his films as per the manufacturer recommendations. I'm sure you tried to bring the best out of your prefered ones amoung all these negs in some fashion or another.

    If you did any kind of change to your negatives and or chosen a different paper grade or even choose a process that would produce the best image you can do or think of. Well today, with computer program like Photoshop you can practically print any negative on any kind of paper or whatever process you can think of. This as been done for years in the printing industry, ok it's not art but the basic are exactly the same.

    Regards

    Yves

     
Received on 05/03/06-08:50:48 AM Z