Leica M10 with Zeiss Distagon 4/18 ZM and Infrared

Yesterday, I picked up a second-hand Zeiss Distagon 4/18mm ZM for some landscape and general wide-angle photos. Since the Zeiss 18mm has a 58mm filter size, and my Lee filter kit contained a 58mm adapter, I wanted to see if that would work.

While browsing my filter set I found found my IR filter, and decided to give that a try. It turns out that the M10 sensor is able to record infrared, but you need relative long exposures (just like my Fuji X-T1), since it's not specially prepared/adapted for IR.

While doing some test shot (out of hand) outside in the full sun I noticed that the Zeiss Distagon has some internal reflection issues while shooting infrared. Can you spot those issues?

View fullsize

View fullsize

Answer: It's bokeh-balls where you don't expect them.

Off-topic: Did Zeiss stop producing the Distagon 4/18mm ZM? It's no longer listed on their website.

The Distagon 4/18mm is missing from their ZM lens line-up

Chromatic-Aberrations ...

is something even the Carl Zeiss lenses seem to suffer from.

CA With Zeiss C-Sonar T* 1.5/50 ZMGood thing that CA doesn't show up after you convert the image to black and white.

Same image, but in black and white

More photos can be found on my SmugMug page.

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).