Article Index

Flare

C Summicron showed fairly noticeable flare in situations with a strong light source positioned within or close to the picture frame. The two shots below demonstrate what you can expect in such situations. You can observe that the lens produces noticeable glare, ghosting as well as color shifts across the frame. Contrast levels also seem to suffer a little bit at wider aperture, which is not that surprising.

 

 

 

Vignetting

The lens produced moderate amount of vignetting on the APS-H camera - at f/2 Imatest clocked color falloff of ~1.5EV, which droppped to ~1EV at f/2.8 and further drops with stopped down aperture.

 

 

In real life you will see some darkening in the corners of a frame at f/2 and to a lesser degree at f/2.8. This will be more noticeable in scenes that generally have lighter scenery. If you have coded your lens, you can try correcting vignetting with the camera's built-in vignetting correction. Alternatively, just use a post-processing tool. If you're using Photoshop, set Vignetting Amount in the Lens Correction option to +20 to compensate. Another option is to use Cornerfix, which will do vignetting correction (along with color shift correction) automatically, assuming you've previously created appropriate lens profile.

 

Vignetting @ f/2 (APS-H)

 

Distortion

Summicron shows a fairly minimal barrel distortion - at ~0.6%, distortion would not be visible in most real life situations and therefore should not be a concern for photographers.