Digital BW, The Print

Joost-
 
 Let's say an image has a wall in it. The overall impression is that the wall is one continuous tone. If you looked closely, though, this continous tone is actually a set or range of similar values. By seperating those local tonalities--increasing their relative differences--you increase the local contrast, and the dimensionality of that area of the image. You don't have to change the overall contrast of the print to affect that area, but it takes skill.
 
 Often, when students begin their apprenticeship to fine printing in the wet darkroom, it's all about seperating tonal values in the shadows. They learn that by properly exposing and developing the film, they can get detail and texture in dark areas that they couldn't get before. Eventually--and this usually takes a long time--they begin to realize that the real challenge isn't the shadows; that's pretty easy. It's controlling the subtle variation of tone in the highlights that often make a beautiful print.
 
 Another example: when students begin to learn the Zone System they gain control over the overall contrast of an image by exposing for the highlights and developing for the shadows. With high contrast scenes you quickly realize that the real challenge isn't controlling overall contrast. That's relatively easy to do. The problem is that reducing the overall contrast of a high contrast scene also reduces local contrast. Areas within the image are reduced in contrast and the image just looks flat and two dimensional. The "secret" is to control both the overall contrast of an image, and it's internal contrast.
 
 In Photoshop it's possible to have localized areas of low contrast, and areas of high contrast. Used well, this is a powerful technique. Combine this with localized sharpening and you can have an enormous effect on the way a print feels, and the way it's viewed.
 
 Hope that helps.
 
 Bill K.
 
 
    
 -----Original Message-----
 From: j.h.j.h@zonnet.nl
 To: DigitalBlackandWhiteThePrint@yahoogroups.com
 Sent: Wed, 22 Nov 2006 3:13 PM
 Subject: [Digital BW] Re: How to get this "3 dimensional quality"?
 
     --- In DigitalBlackandWhiteThePrint@yahoogroups.com, BKPhoto@... 
 wrote:
 Hi Bill,
 
 Thanks for your comment as well. Soem questions though:
 
 > I'd add to Tyler's comments that the illusive "three dimensional 
 quality" idea is closely related to the internal tonal structure of 
 an image. This has always been true, from the earliest photographic 
 printing processes to inkjet printing. Wet darkroom printers often 
 refer to this as the "internal contrast" of a print; the local 
 contrast rather than the overall contrast. Internal contrast helps 
 separate close values and, in my experience, this is a major 
 contributor to that dimensional quality.
 
 I'm not sure I completely get what you mean. I'm having trouble to 
 visualize the length scale of "local". Are you meaning the 
 microstructure/texture, or over a more larger scale, let's say 5% of 
 the image, typically parts of key objects. or both? Could you 
 elaborate it bit furhter on this? 
 
 > When you add hue, or subtle shifts in color, in a monochrome image 
 you get an accumulative effect. The color is perceived as part of the 
 internal contrast of the image. 
 
 I think I understand that one.
 
 > Lastly, this sense of internal contrast is affected by any number 
 of issues: the grain structure of the image, sharpness (optical and 
 printing), and the size of the print.
 
 Not sure I understand this one, but as said before: I have some 
 trouble understanding the concept.
 
 Joost
 
      
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