Gray, banded sky in Luminance HDR output

Question

I captured a scene with a crummy IP camera at -2, 0, +2 EV intending to join them into an HDR image: Image Gallery

When I create a new HDR image with Luminance HDR 2.5.1., the exposure values are somehow read as -1.99, +0.00, +0.32, which is unexpected as the EXIF data says -2, 0, +2. I adjust these parameters to their expected values and then use Profile 1 to create the image.

Here's what I get:

The sky looks terrible, with solid blotches of gray that are much darker than the source image. It seems to be this way regardless off which tone mapping operator I choose. I understand if the sky is blown-out in the resulting image, but how can I make the appearance less dramatic?

Answer 1

... but how can I make the appearance less dramatic?

Don't blow out the sky. There's no detail there. Every pixel is the same exact value. No matter what you do in post the parts that are blown out will all be uniform in color and brightness.

Answer 2

Perhaps your camera is unable do capture at +2 EV in the given circumstances and the true exposure is +0.32, as reported by Luminance HDR. Forcing the incorrect EV creates a contradiction which gives you the absurd sky color.

Answer 3

I suspect the tree branches to be the culprit: They tend to move (if there is some wind) from pic to pic, and the alignment algo (at least not Hugin used by Luminance) can't cope with this issue. It's simply ghosting. I've had this problem several times myself.

You could try out anti-ghosting, if your HDR offers it.