Re: gloy for tricolor on yupo?

Mark & all,

I don't deny the usefulness of a step tablet, I use it all the time for my film tests. I agree with you that for exchanges with the external world it's much better to speak the same language and to use and apply the same standards. There are many standards we could agree on as I'm sure you are well aware.

All this is fine but what I'm saying is, in a digital world you might as well go digital all the way. I know we can play with number all we like and even convert pixel values to EV values taking into acount the gamma curve and everything else I'm not mentioning here. I also know that a pixel value is in it's way a standard as well.

When I or any one else sees a pixel on the screen converts it to it's negative value, print this negative pixel on pictorico and expose some fine paper with this negative, this pixel value (and it's inverse) follows you all the way, scan this print an you close the loop. In other words, with the scan you have everything you need to figure out what happen to your pixel along its path. At each step of the process at hand, the pixel value is kind of bump around but just as with anything else we can apply digital (I don't want to use the M word) transformation (kind of debumping) such that we can have an alt-print that present the same qualities we obtained on our screen.

You would be right to say, playing with numbers is playing with numbers and using a scanner or a reflective densitometer to close the loop, you still have to use "digital" transformation so why not stick to the old fashion way of doing things (density)? Well, I would say and I'm sure you'll agree with me, every time you manipulate number you loose something, so however you look at it, when scanning your alt-print to close the loop, you never have to convert density to pixel value for one and what I consider the most important, you have a consistent unit of measure at every step of the way and from the person sitting in front of the computer, there is not even a single computation involve by this person. I mean, all this adjusment or curve thing can be done graphically in a few step or in a single step using numbers, if you don't count the verification stage of course. All this is theory of course and in practice I'll be the first to admit things are more complicated then that but not because the theory isn't right and a lot more because it's practically impossible to make identical alt-print manually. So it takes time and a few trials to average out unevenness sort of speak.

I know you wrote a book on the subject which I haven't read and every one says it's a must have, which is probably true. In practical term however, using a manufactured step tablet or one you made yourself will in the end give you the same result. By this I mean in the end, the last print we make and consider as our "fine" print will never be the same for both of us and it wont be even close to what we see on the screen. The first negative we made however "precice" it may be, will never be the same as the last we used for our "fine" print. I would even add the same thing will happen to each "fine" print we make. All this is bound to happen because both medium (screen & paper) are so basically different in properties and characteristics that there is simply no way the best image we can make on screen would translate directly into the best image we can make on paper. This is the kind of thought I have the most difficulty explaining with my limited vocabulary but I'll try again using someone else words. Ansel Adams said something like this, the original image captured (be it a negative, a slide or a digital image directly) is kind of the partition and the print is kind of the performance of the artist. This is way, I consider each original image individually and each performance and or artist also individually. We are human are our moods are as changing as the wheather and what we arrive at on a screen and consider our "finest" performance, will invariably have qualities quite different from the same image we consider our "finest" performance on paper. I don't see a way around this reality, though I said a few times that it would be nice to be able to see how our paper prints would look like on a screen, I already know it is futile to think its possible. Even a scan of a print will not give me the same let say reactions.

Maybe I'm just trying to convinced myself that printing step tablets is a total waste of time and energy because in the end, it is not important how you get there, it's the "fine" print, the end result and that outweight anything else.

Regards
Yves

  ----- Original Message -----
  From: Ender100@aol.com
  To: alt-photo-process-l@usask.ca
  Sent: Saturday, April 01, 2006 5:31 AM
  Subject: Re: gloy for tricolor on yupo?

  Yves,

  A standard step tablet is far more usefull for determining exposures and exposure scales—because it is a standard. Because it is standardized, then two different people can have a meaningful discussion of their outcomes, exposures, etc. A digital step tablet is alwalys of unknown value and does not allow such a discussion or comparison to take place.

  One can easily account for the Base + Fog of the standard step tablet and factor that out when necessary,
  Best Wishes,

  Mark Nelson
  Precision Digital Negatives

  In a message dated 3/31/06 5:57:29 AM, gauvreau-yves@sympatico.ca writes:

    Hi,

    when I see below that one should use a step tablet to find proper exposure,
    I would suggest a couple of reason to be doubting these measures. First,
    unless the material you use as your negative is exactly the same as for your
    step tablet which is rarely the case, you wouldn't be sure they behave
    exactly the same way mostly because of there (probably) different response
    to UV, if you make digital negatives, then I would suggest making a step
    tablet the same way you intend to make your negative since this way you can
    establish a direct relationship with what you see on screen (pixel values),
    your negative and your print if you are using a scanner of course. Creating
    an adjustment curve using this pixel values instead of densities is
    pratically child play. A traditional step tablet would give you more work to
    establish this same relationship.

    Regards
    Yves

    ----- Original Message -----
    From: "Katharine Thayer" <kthayer@pacifier.com>
    To: <alt-photo-process-l@sask.usask.ca>
    Sent: Friday, March 31, 2006 1:02 AM
    Subject: Re: gloy for tricolor on yupo?

>
> On Mar 30, 2006, at 8:03 PM, Christina Z. Anderson wrote:
>
> >
> >
> > The 6 minute printing time, given UVBL and 15% dichromate and my

> > workflow gives me a layer that develops in an hour and yet can also
> > be spray developed without the layer sloughing off. It also
> > provides a deep enough colored layer. At 5 minutes it is not bad
> > either, but the layer of gum is a bit more tenuous and not as
> > strongly colored--the more exposure, the deeper the gum layer is
> > and hence the more pigment remains on the paper. At least, in side
> > by side step wedges exposed at 1, 2, 3, 4, 5, and 6 minutes this is
> > the case--the colored layer thickens and therefore deepens with
> > exposure. If my website ever gets up it'll show this little example.
>
>
> Well, of course, all of this goes without saying: for each
> combination of light, dichromate, film, paper, etc etc there is a
> "best" exposure, which can easily be determined with a step wedge,
> and which produces the optimal hardening of the gum layer; anything
> less than that exposure will result in less than optimal gum
> hardening. I would be very surprised if there are any gum printers
> who don't know that.
>
> But my point, which I wonder if you've missed, was that this
> "best" exposure is different for every system of equipment,
> materials, etc. It's hardly surprising that your students found that
> the same exposure worked for them, given that I would assume that
> they would be using the same equipment and materials, but surely
> you're not suggesting that 6 minutes is an optimal exposure in some
> kind of general and absolute sense.
>
> Katharine
>
Received on Sat Apr 1 10:09:59 2006