LensRentals has loaned me a Hasselblad XCD 135mm f/2.8 lens for testing. For the first test, I used a Zeiss Siemens star about 20 feet away. Edelkrone Tripod X Pro Arca Swiss C1 Manual exposure ISO 100 Self-time set to 4 seconds AF-S, six shots per f-stop Center and lower left corner f/2.8, f/4, f/5.6,… [Read More]