Lens Flare Question

A question for you optics experts out there...

On the final morning of my Galapagos trip we had a very nice sunrise. Once the sun crested the clouds, I tried to shoot some frigatebirds silhouetted against the sunrise. I expected with a full sun to get some lens flare. What I didn't expect was for these long beams to flare all the way across the frame.

I have not seen this type of flare before, and am wondering if this was the result of me having a teleconverter on (1.4x mounted on a 70-200mm 2.8 lens), or if this type of flare is more typical than I thought.

This image is a throw-away, of course, but the beams did interfere with what I felt were some nice images too.

Anyone have a sense of what would cause these long beams versus the usual "round" flare that we often see in the frame?

Thanks,
Max

Max, my limited knowledge of flare has me thinking that this isn't from the lens combo. I expect flare to be from the small amount of reflection (typically 0.5 - 1% expected for an antireflection coated lens) at each lens surface. That's why you typically see a series of spots (just as you say), each one from a different lens surface. To get continuous streaks like you have here, I wonder if it has somehow come off the edge of the mirror as it flips up or down...but the mirror should only move well before the shutter opens or well after it closes.... Do the angle or number of beams change with the position of the sun in the frame? Another (wild) thought is that there might be a spot of dirt on a lens surface (main or TE) right where the sun is. That would cause beams going in all directions if it was round, but they would be directional if it was elongated (like a hair).

BTW, In this image, I find those beams interesting...just wish they didn't overlap the bird.

Beats me, sorry, but wanted to just say, I'd not throw it away. Pretty cool image.

Thanks guys. I appreciate the feedback.

Mark, to answer your question: the angle of the beams/flare does change in accordance with the camera/lens position. In my horizontal compositions, the beams are more on a horizontal plane (example attached) so it does appear to be tied to how I was holding the camera. There are no noticeable marks on the lens or teleconverter, so it should not have been caused by a "dirty" lens at least. I also did not use any filters.

I do have a few other shots from this sunrise that I find really appealing, but the flare is prominent and a bit of a distraction. If I have time, I'll try to post something in the Avian gallery soon.

Max

Max, if you rotate the 2nd image to vertical, the sun's position and ray angles looks similar (but I don't think that the location is the answer here). The clouds in it are in front of the sun, which could cause crepuscular rays (and the dimness of those in this second image feels right for those). However, the sun is well above the clouds in your original post, so I don't think crepuscular rays are the answer either (unless it's those very tiny clouds, which seems unlikely). Sadly, that exhausts my ideas. I doubt that I need to say this to you, but I'd sure try some more shots under similar conditions with and with out the TE. Definitely a disturbing mystery.

Hey Max, First off, like Mark and John I think the posted images are great and wouldn't get rid of them myself! My best guess at what happened is that you were shooting with gear that had cooled overnight, and as the ambient air warmed up the glass fogged up. When you wiped it down you created streaks that caught the sun's light. It's probably not the case, but i'll post two images below that illustrate something similar that happened to me. I slept in my truck so I could be at Seal Rocks State Park before sunrise, and was shooting the setting full moon when the warming air caused my lens to fog up. I wiped it off and the next photo I took had a long (and pretty cool) streak through the moon! After a few shots it disappeared, so I concluded it was from the way I wiped the lens. Again, probably not the case but it's my best guess!

2nd image with the streak.

Interesting, Thomas. Because it was first thing in the morning, that may have been the cause. A few folks had fogging issues during a couple mornings on the trip, and though I don't remember specifically if that happened to me, I may have given it a cleaning (or perhaps a "smudging") that morning.

Max