HRD Noise in black sky

[Trevor Harris]

Hey all,

First post on this forum, here's to many more!

I've got a general question about HDR. I've searched the web for an answer but couldn't find any, and my apologies if this has already been answered.

Lets set the stage: Your taking a hdr, useing 3 or more exposures on a night shot of a city. your longest photo is around 5 seconds. In this photo, and all the rest, the majorty if the sky is black with maybe some light flare at the horizon. That's cool, you like it that way.

A few hours later, you try to spice it up with some HDR magic. Photomatix is the program, you do your usually routine, and what the heck went wrong?? The city comes out nice, but the sky is noisy as hell.. it's not black, it's blotchy red!

I get whats going on, photomatix is trying to brighten it up, to get it somewhere in the middle of the histogram, BUT, it's supposed to be black, it's a night sky. Messing around with all the dials does help, but what helps the blotchy sky, ruins your nice cityscape. I realize this can be corrected in photoshop, but is there another way? Has anyone else encountered this problem, or does EVERYONE encounter this problem and use photoshop to fix it?

Thanking you in advance,
Trevor

 

[lyonsroar]

HDR Discussions - The Photo Forum - Photography Discussion Forum

 

[SlickSalmon]

I've just been working on such an image, so I'll take a stab at answering. The situation is as you describe. If you use Photomatix Details Enhancer, you're guaranteed to increase noise in a dark sky. Exposure Fusion is far more forgiving. However, virtually all HDR images require some kind of post-processing, so Photoshop or something like it is inevitable.

 

[Trevor Harris]

Thanks, SlickSalmon! I figured as much, but I just wanted to confirm.
lyonsroar, sorry, I didn't see that forum. Moderators, could you please relocate this thread?