What causes black flare?

[Poco]

I've uploaded an image to the technical gallery that has me scratching my head. What would cause the black flare above the big white square section of the building? I shot doubles and the flare is present on both sheets, so it's not processing, ... definitely flare. Now I've seen flare that shows up as light spots before, but never as dark spots and I'm wondering what causes this reversal. Ideas?

[wfwhitaker]

I can't see it on my monitor. But if I use my imagination, maybe I can see something which resembles industrial exhaust. Any stacks located behind the building?

What film/processing did you use?

[Poco]

Will,

It's not exhaust. It's one of those things that you can spot better by not looking directly at it. It's one of those typical faceted blobs you get from sun reflection (much more obvious with PS manipulation) ...only it's dark, instead of light. I came across this once before on a B&W shot where it was much more obvious, but convinced myself I'd screwed up processing since the phenomenon made no sense. But I now know it's very real, if rare, that flare will sometimes reverse itself. I'm just wondering why.

Film was 160 NC in regulare C41

[Dave Parker]

Hmmm, I can't see it on my monitor either???

Dave

[pentaxuser]

I eventually could see it after about 5 mins! It's hardly black. More of a very, very light brown and as near as I can make out, it isn't quite the classic hexagonal flare shape either. I've only had this once on a B&W shot taken with the sun just to one side of the viewfinder. For all the world it's as if you had the lightest of tea or coffee splashes you get if a drop falls on a picture and spreads and you quickly mop it up but inevitably leave just a trace of stain. Reason? Haven't a clue, I am afraid.

If the mark on the print is just as faint, test it on your friends and see how many spot it. Very few I'd be willing to bet. It's a nice shot

[Poco]

Okay, I photoshopped the crap out of it (but I repeat myself) and it should be obvious now.

Thanks, Pentax, for confirming I'm not nutz. It DOES sometimes happen.

[Helen B]

Why do you think that it isn't a processing effect? Exactly how were the sheets processed? Is the dark patch completely identical on both sheets, or just similar?

It's difficult to tell from the JPEG even with the contrast boosted enormously, but the dark patch does not look like a perfect pentagon or hexagon or whatever-agon. How many blades does your aperture have? Is it a perfect pentagon or hexagon on the original? I could imagine a situation in which flare was caused by light reflecting off the aperture blades, in which case the opening could appear as a dark patch.

Best,
Helen

[Konical]

Good Morning, Poco,

Doesn't show up for me, either.

Konical

[Dave Parker]

I can now see a shadow above the building, it does not seem to have the normal characteristics of what would be considered flare, it looks more like an inverse reflection off the white side of the building, perhaps black reflection from a high contrast situation and black asphalt on the ground, but again, it looks more like a shadow of some sort being reflected.

Dave

[Bob Carnie]

If the black spot is in the identical spot in both negatives I would think it is flare caused by a reflection in the lens or lens hood.
When printing , if you have a burn card with white paper on top and a burn hole cut out, standing beside your print, I have sometimes seen a plus density or black mark on the print that mimics the hole in the burn card.It could be something as simple as a dark piece of dust causing a minus density reflection on the negative.

If the black spot is in a different position then I would then agree with Helen and assume it is improper agitation in the development of the negative.
Processing errors are most evident in large expanses of nuetral tones like skys and grey background.