Day 11: Another Day in the Field

After the scare of the focus-shift had settled, I 'mastered' the compensation technique for this 'problem'. Turns out that moving myself about 2 inched towards the object AFTER I focussed on it, the object would be in focus (results may vary depending of the distance to the object). The further you're away, the smaller the compensation needs to be.

Both images were shot @ f/1.5 (Carl-Zeiss C-Sonnar 1.5/50mm ZM T*) with a focus distance of 2 to 3 metres with little to no compensation for the focus shift. In the first image there's a bee just left of the flower/weed.

Day 8: Focus-Shift

No matter how extensive your research is, there's always something (bad??) you miss. In this case it's focus-shift with fast lenses. Focus-shift means that the actual focuspoint is not exactly where you might think (also known as front- or backfocus). In the case of the Zeiss C-Sonnar 1.5/50mm it occurs generally @f/1.5 or @f/2.8. My Zeiss 50mm has this 'problem' @ f/1.5, which means that the lens is calibrated for film. Problem is a big word, since it seems to be inherent to the C-Sonnar design. It's also something that occurs a lot with a rangefinder system.

To solve this, I need to focus on the ears instead on the eyes when I shoot a portrait, or just compensate bij moving a bit forward after focussing. I could have Zeiss recalibrate the lens for free (while still in warrenty), but that means shifting the problem to another aperture.

If it turns out to be a real problem, I could always go for a Leica M Summicron 2/50mm (which I have still on backorder along with the Leica M Summicron 2/35).