Thanks for the information. I will look into this.
Originally Posted by Tom Stanworth
You may be right about the speed difference. However, comparing the EFS of different developers is one of the most difficult characteristics to compare. You really need to do this with some kind of sensitometric control procedures. In-camera methods are inherently faulty due to the lack of exposure precision in our systems. Plus, for the comparison to be valid you must develop the comparison negatives to the exact same CI, and unless you plot the curves it is difficult or impossible to know for certain when this has been achieved.