jaapv
RFF Sponsoring Member.
KoNickon said:As someone else mentioned, it is odd how the Summicron images are so light --
The explanation is simple- Different lenses have different light transmission factors, due to different coatings and glass. The aperture is a mathematical value and does not take this into account, the stops on an aperture ring are calculated by the maker, not measured. If you measure exposure with an external meter you can run into variations in light transmission of over half a stop - as happened here.
A very interesting and informative test btw. Thank you 🙂