I used a red filter here hoping to take advantage of the dramatic skies that had complementary blue color. I did not get the effect I expected maybe because of exposure, or misreading the filter factor. I exposed the HP5 from a base of 200, with 3 stops for the red filter so I set the camera ISO to ISO 50 (even though 3 stops would have put me at 25). This gave me camera settings that were F8@125. My good friend Steve Brigidi, an accomplished film photographer, suggested shooting this film at ISO 200. I developed the film to ISO 200. I am still learning the variables of changing image characteristics from development times. In my great AGO Film Processor, I take 15% off of the Massive Development Chart’s suggested development time, leaving me with 6M (instead of 7 minutes without constant agitation). The negatives using the AGO come out streak free and evenly developed with no leaking of chemicals. The unit timer progresses through the development, stop and fix stages on a timer. This is a great but expensive unit that I highly recommend. A great feature is the unit automatically adjusts the development time based on the actual temperature of the water. For example, if the suggested time is 6 minutes at 68F and if your water temperature is 70F, then the unit will lessen the development time automatically. I have gotten very consistent results developing film using this unit, including C-41. I am not a fan of C-41 because of the noxious nature of the chemicals, but damn, this thing works. There are different baked in programs for different C-41 chemicals also, and the unit can wirelessly download firmware updates and new development recipes. I am impressed!