Quote Originally Posted by sergio caetano
In order to avoid Callier Effect is advisable to use diffused light. This is something well noticeable with condensers (colimated light). See examples in the book Fine Print by Fred Picker.
Sergio, The so called Callier effect is something that has been bantered about for many years. I accepted it without testing the validity for myself for a long time. I have found that this was probably the excuse that was given for not knowing how to adjust development to the DR needed. My experience has shown the Callier effect lacks validity. If you haven't tried this for yourself, then I encourage you to determine the accuracy of these statements without simply accepting either Ansel Adams or Fred Pickers pronouncements.