Agfa Library: Technical Terms - U



















 




U

Ultra short time effect

With photographic materials, very short exposure times combined with
high light intensities result in a loss of speed, flatter contrast and,
with color materials, in color shifts and cross casts.

Like very long exposure times with low light intensity (reciprocity failure), very
short exposure times with correspondingly higher light intensity also
affect the general speed, the gradation
and the relative profile of the color density curves of the
photo material.

The ultra short time effect ( syn.: high intensity reciprocity failure)
comes about through the formation of a disperse latent image (whereby,
as the result of intensive short time exposure, several small,
difficult to develop latent image nuclei form on a silver-halide
crystal instead of a single large latent image nucleus.
The photographic effect of the exposure is reduced as a result. This is
equivalent to a reduction in speed. At exposure times below 0.001
seconds, black-and-white materials can undergo a decline in the
relative speed and a flattening out of the gradation at the same time.
With color materials, the relative sensitivities of the individual
color-forming emulsion layers can alter (e.g. cross cast).



 



 previous
  alphabetic index
next



 



 



Photohome
- Agfa Library - Technical Terms - "U" <-- you're
here



About
Agfa | Agfa Arcade | Agfahome | Photohome
Search | News | Feedback
Agfa Photo Gallery | Advanced Photo System | Trends & Experiences | Products

©1996 by Agfa-Gevaert AG, Copyright and Trademark
Information