Quote Originally Posted by Gerald C Koch View Post
The color temperature of daylight can vary considerably depending on the position of the sun and atmospheric conditions. It can go from below 5000K to over 12000K. It is not a very reliable reference source.
yes you are right, that's why I was thinking that maybe using electronic flash with correct filtration close to morning or afternoon daylight temperature can be used for film speed / development test. I used reference to the sunlight bc I'm going to use film under sunlight, only test would be performed using flash.

I'm trying to do the film test as described in Way Beyond Monochrome book using stouffer step wedge. I was trying to use sunlight but always light changes (or I'm too slow) all the time at my location and I was not able to get the consistent results. That's why I was thinking to use flash with gel on it to be close to the sunlight.