Photomatix Pro HDR artefacts

HaveCameraWillTravel

Hi. I'm using a trial version of Photomatix Pro for HDR work, and I am now reconsidering buying the license. Here's why.

When I shoot a bracket for HDR, and the subject has bright lights in it (city at night, Christmas trees, lighthouses at night, etc.), I almost always get an annoying gray or black blob in the centers of the highlights. Arrghh! Christmas trees lit at night produce a whole bunch of these artefacts which are hard to clone out. Have any of you had this problem with Photomatix Pro? Inverted contrast is one thing, but black blobs are hideous!

I always shoot HDR with a tripod and a cable release, changing only the shutter speed in one or two stop increments in my bracket. Anywhere from 3 shots, two stops apart up to 9 shots, one stop apart. Doesn't matter, still get these blobs. Only in Tone Mapping (Compressor or Enhancer) mode. Fusion doesn't cause this problem. Ghost reduction on or off, alignment options, chromatic aberration correction on or off, number of shots, stops between shots, setting any of the tone mapping controls, all have no effect on the artefacts.

If any of you have run into this problem, and have a fix (maybe I am doing something wrong), please let me know. I'm itching to put up more HDR Holiday lights pictures up on this blog, but this is holding me back. Perhaps it is the software and there is some other HDR tool that doesn't have this problem. Any help is much appreciated.

Art

kdog

Gray maybe, but black? Regardless, it sounds like you've got blown highlights on your most under-exposed image. That left most image has to have no blowouts whatsoever. If that's not your problem, then we'd probably need to know your exact workflow, and maybe look at an example image set.

Sam

You could give NIK HDR software a try.

Sam

HaveCameraWillTravel

kdog wrote: »

Gray maybe, but black? Regardless, it sounds like you've got blown highlights on your most under-exposed image. That left most image has to have no blowouts whatsoever. If that's not your problem, then we'd probably need to know your exact workflow, and maybe look at an example image set.

I never thought of that. Some series do not give me this problem, others do. I had realized that shooting Christmas lights at night required a lot more images, because you have to really underexpose to not blow the centers of the bulbs. I think I was trying to speed things up in processing by ignoring to use those extra shots in my workflow.

I'm going to take up your idea and reprocess the troublesome ones by using all the shots (at night I take up to 11 shots one stop apart), and in shooting in the future, make sure my most underexposed image has no blown highlights. This is not apparent in the camera's playback unless a full zoom is done - which I'll have to do more often.

Thanks for the tips!

Art.

HaveCameraWillTravel

Sam wrote: »

You could give NIK HDR software a try.

Sam

Thank you, but before I do that, I'm going to try the first idea of making sure I have a full series of exposures with no blown highlights in the most underexposed image. If that fails to correct the artefact problem, then I will try NIK HDR. I am just starting to get comfortable with Photomatix and I'm starting to get a feel for the controls, so I want to give it a fair shake, and make sure I put in the right images.

Art

HaveCameraWillTravel

I just tried kdog's suggestion, redoing one of my HDRs using all the exposures down to the darkest one, rather than skipping the last one or two to save processing time. Sure enough, the dark spots disappeared from the highlights. Oh, and as for the black spots - those turned out to be only in areas where ghost reduction had failed to remove all of the ghost. Now I'm going to make sure I take more underexposed shots. I also read that Photomatix Pro prefers 2-stop intervals, so I won't have to take so many shots to cover the dynamic range.

kdog

Glad to hear you're making progress. Capturing the entire range of the scene is really the key, regardless of what HDR software you use.