Quote Originally Posted by Maris View Post
My experience with Arista EDU ultra 100 is that the reciprocity failure is nowhere near as dreadful as the official figures imply. For a 2 second exposure I would not make any correction at all. Here are the numbers I use:
1 second metered give 1 second.
4 seconds metered give 5 seconds.
15 seconds metered give 20 seconds.
30 seconds metered give 45 seconds.
2 minutes metered give 4 minutes.

Hi, Thank you for this information. The chart in Pinhole Assist are based on Arista official data which is scarse : (1 second -> 2x, 10 seconds -> 8x, 100 seconds ->16x).
The charts within PinholeAssist for Arista were made with this data, using linear interpolation. I should have used interpolation on the derivative
For t=2s, the 1st method gives 10 seconds, and the 2nd method 5 second.
For t=4s, the 1st method gives 28 seconds, and the 2nd method 16 second.

This is better, but still higher than your figures.
I will release an updated (with 2nd method) data file soon. I would like to distribute an alternate correction curve based on your data, if you authorize me to do so.