[stoppingdown]

Yesterday I tested my SEL1670Z against the full sun of the middle of the day (more or less). It's not a typical kind of shot I take   but as I noted problems even when shooting the sun near the sunset (more typical kind of shot), I wanted to study better the phenomenon.

 

In short, the sun looks as the worst problem of this lens: you can play around with various focals and apertures, and some heavy artefacts (typically green blobs) are always here. In the worst cases they are huge and ruin the photo. In just a few cases I managed to make them small as in the picture, and in this form they could be easily fixed in pp. 

 

What puzzles me is the diagonal upper-left -> lower-right bright streak around the sun. I mean, I know that sun produces streaks with many lenses and it's normal. But so far I've seen more regularly distributed streaks (some even pleasing), not a fixed one, always at the same angle, wherever the sun in the frame is (other artefacts, such as green blobs, move around).

 

In my optics ignorance, I'm curious about what is the cause of such an artefact and why it is always in the same position; I would have said that moving the sun around the lens it should have rotated and even got to be in a specular layout.

 

Thanks.