razocaine_07
Member
Kodak Ektar 100 is the current color C41 fine grain leader.
In the Kodak Ektar 100 datasheet it states as follows:
Adjustments for Long and Short Exposures
No filter correction or exposure compensation is required for exposures from 1/10,000 second to 1 second. For critical applications with longer exposure times, make tests under our conditions.
This is standard caveat in all the color negative datasheets so you will have to experiment. I have made many exposures from minimum of minutes to several hours long with many different color C41 brands and have not encountered any reciprocity failures. Instead, you may encounter different light sources with various light temperatures that you can easily deal with in post if you are so inclined.
Thanks for the image comparisons, it looks like the 800 portra still has relevantely fine grain despite the higher speed. Its good to know someone who hasn't had any issues with recip. failure despite huge exposures, much longer than I will probably need to achieve.