Voigtlander Ultron 27 mm f/2 review - Coma, astigmatism and bokeh

Have you rated your lenses yet?

Voigtlander Ultron 27 mm f/2

8 January 2024

Maciej Latałło

7. Coma, astigmatism and bokeh

So far the Ultron 2/27 fared very well in most of testing categories. Still, the weaker performance on edges of the frame has to stem from something. Looking at the photos below we can say that coma certainly contributes to that. At the maximum relative aperture its level is very high; it makes itself felt even on stopping down the aperture to f/2.8. It seems we found the first big slip-up of the tested Ultron.

X-T2, f/2.0, center	X-T2, f/2.0, Corner

X-T2, f/2.8, center	X-T2, f/2.8, Corner

Astigmatism, understood as an average difference between horizontal and vertical MTF50 function values, amounted to 6%. It's a value on the borderline between low and very low level so we assess the performance in this category very well. We sould also mention the fact that astigmatism is bothersome only at the maximum relative aperture because from f/2.8 upwards it becomes imperceptible.

Please Support Us

If you enjoy our reviews and articles, and you want us to continue our work please, support our website by donating through PayPal. The funds are going to be used for paying our editorial team, renting servers, and equipping our testing studio; only that way we will be able to continue providing you interesting content for free.

- - - - - - - - - - - - - - - - - advertisement - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Defocused circles of light, generated by the Ultron 2/27, look sensibly well. The light spread inside them is even, without any onion ring bokeh effect. We can complain only about a bit brighter rim and not especially circular aperture – it features 10 diaphragm blades but it is not able to generate fully round images of circles. Mechanical vignetting is a very nice surprise for a change. I thought that in a case of such a midget it would be visible even on stopping down the aperture by 2 EV; meanwhile the circle we got in the frame corner by f/4.0 doesn't feature any truncations or deformations.