HI, I decided to use above combination because it develop in higher temp. - 24 degree C and have longer than 5 min. dev. time, with rotary tank - according to data sheet. Because my location is rather hot and difficult to keep in lower temperature. I usuall shot with a no. 8 filter and calumat 150/5.6 mc lense. Since I want to concentrate on the subjects instead of chemistry, should anyone could share your experience? Should i follow the datasheet rigidly?