What the government tells us is a summary of an industry study. Here is what the industry study tells us, based on density measures to determine "functional" damage:
Originally Posted by pbromaghin
Color negative film
The results of this test showed that banding (uneven density areas) was noticed after 25
passes with ISO 400 color negative film, and after 10 passes with ISO 800 color negative
film. Prints were made from the ISO 400 film, and it was noticed that there was only a
minimal color shift through the scan sequences. Also there was loss of contrast, and an
increase in granularity starting at pass 10 and increased as the number of scans increased.
This was especially noticeable in the under exposed frames. In each case the base fog
(density of the unexposed areas) increased with the number of passes. The density of the
exposed areas increased as well, but in smaller amounts.
Black and White film
An uneven fog pattern was noticed, especially with ISO 3200 film between 1 and 5 passes. At 25 passes this effect was extreme.
Last edited by BrianShaw; 09-23-2013 at 03:17 PM. Click to view previous post history.