Universar Auto 55mm f/2.8 - Sharpness

Sharpness of the Universar Auto 55mm lens when focusing to infinity.

Below are a series of photographs taken with the Universar Auto 55mm f/2.8 lens, focusing to infinity (or nearly), using all apertures.

I was at Burrero Beach without a tripod, so I leaned the camera against a wall. That's why the photos are presented straight, without tilting the horizon, which is usually more useful for these tests.

All the photos were taken with a Fujifilm X-A2 camera, which features an APS-C sensor with a crop factor of 1.52. Additionally, I used a Viltrox EF-M2 focal reducer, which has a factor of 0.71x. As a result, the effective focal length of the lens on the camera is approximately 59.36mm in full-frame equivalent.

Since I didn't have the tripod with me or any remote shutter release cable, I set the camera to AUTO ISO, with a minimum shutter speed of 1/125, which caused the ISO to increase more than desired for photos with smaller apertures, potentially resulting in some loss of sharpness, but minimal.

For each aperture, I show 3 crops: center, middle, and corner. You can click on each image to see the crops at 100%.

At f/2.8, the lens is very soft, with low contrast and a lot of halo, but closing to f/4 significantly improves sharpness. From f/5.6 onwards, it seems to be excellent. The middle area from f/8 onwards is very good.

The corners, in general, are a disaster, but perhaps at f/16 is where they look best. At f/16, precisely the entire image begins to suffer from diffraction. Perhaps the focal reducer contributes to worsening the corners, I'm not sure, it would need to be tested. It's also worth noting that my copy of the lens is not well-centered, and the corners have uneven performance.