Silver density

The dyes or dye precursors may be initially diffusible in alkaU, in which case they will be immobilized imagewise, or they may be initially immobile in alkaU and released imagewise to transfer. Positive-working processes produce dye transfer density inversely related to the developed silver density conversely, negative-working processes produce dye transfer density in direct proportion to the developed silver. 

The term fog is used to describe the unwanted silver density which is invariably obtained in unexposed areas of an emulsion when it undergoes development. Fog can be caused by exposure to stray radiation or by the action of chemicals either incorporated in the emulsion itself or in the development solution. It can be restrained by the addition of so-called antifoggants to the emulsion or processing solution. 

In the case of a three-color process, three-color records are made from the subject recording, in terms of silver densities, the relative amounts of red, green, and blue present in various areas of the subject. 

Most people don t realize how much depth of printing establishes the final image tone and are confused when they get weak tones from a toning formula. This is often the case when negatives don t have enough silver density, spectral density or have a fogged base. 

The charge traps result in a strong dependence of the current on silver density and on the directi( i and sweep rate of the voltage. Electron storage inside the... 

Thus density superadditivity is only an apparent superadditivity even though the sum of the silver densities for the separate developers A and B appears to be less than that for the A + B curve. This is because developer B would not have an induction period in the presence of developer A and so would contribute to the overall development almost immediately, giving the broken curve A + B which is merely additive. In kinetic terms, true superadditivity occurs when the rate of growth of density or silver for the combined A with B developer is greater than the sum of the rates of growth of density or silver for the A developer and the B developer separately. 

Figure 21. A family of experiments, of the silver density difference produced by treating film samples paralleling Figure 20 with optical latensification after latent image degradation by one of several buffer solutions.

Figure 5.3, Relationship between exposure ( ) and developed silver density (D). The continuous curve illustrates the basic sensitometry obtained in negative-working systems. Increasing exposure results in increasing developed (optical) density (elemental silver or image dye in the case of colour systems). The dotted curve illustrates positive-working sensitometry, where increasing exposure results in decreasing developed density...

The inelastic scattering can be modeled as a continuous process causing an energy loss/unit distance (d /ds) [66]. At 20keV, this is about leV/nm for polymers, density lg/cm and 7eV/nm for silver, density 10g/cm [38]. The energy loss rate increases less than linearly with (electron) density because some excitations are not available in heavy elements. For example, Ag Ka is >25keV. 

At a local pawn shop a student finds a medallion that the shop owner insists is pure platinum. However, the student suspects that the medallion may actually be silver and thus much less valuable. The student buys the medallion only after the shop owner agrees to refund the price if the medallion is returned within two days. The student, a chemistry major, then takes the medallion to her lab and measures its density as follows. She first weighs the medallion and finds its mass to be 55.64 g. She then places some water in a graduated cylinder and reads the volume as 75.2 mL. Next she drops the medallion into the cylinder and reads the new volume as 77.8 mL. Is the medallion platinum (density = 21.4 g/cm ) or silver (density = 10.5 g/cm ) ... 

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