After reading great review of 7artisans 35mm F1.2 on 35MMC I explored more details about Sonnar design C Sonnar T* optical formula. I was wondering what happens to the picture if the 6th lens element is placed in same group with 4th and 5th, like it’s done in Zeiss Sonnar C 50mm F1.5 ZM T*.
It’s quite easy to try, because 7artians engineers made the rear lens block very easy to disassemble without using any tools. Regular rubber glove provides firm grip and enough torque to unscrew the metal ring around the 6th element. Then it’s easy to pull out the 6th glass, remove the metal shim under it and place it back, and screw the metal ring to it’s place.
That shim is nicely blackened as well as glass edges. The shim dimensions are: 0.65mm thick, 1.995mm outer diameter, 1.8mm inner diameter.
Here are 100% center crops made with 7artisans 35mm F1.2 original optics (left samples), and shifted 6th element (right samples) on Fuji X-E2s camera (click to see 100% size).
This “Sonnar-like” modification adds 7artisans 35mm F1.2 very soft and dreamy overall look at F1.2, though preserving high level of details. The OOF area also looks more creamy and natural. It reminds me the “soft focus” effect of Fujifilm X cameras. I like how the modified lens performs, it becomes very different lens, ans still renders very sharp starting from F2.8.
I’ve reverted modification for now because still want to play more with original optical design, but will definitly try to shoot with modded formula in future, it should be fun : )