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Thread: HDR color problems near highlights - why does this happen, and how can I fix/stop it?

  1. #1
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    HDR color problems near highlights - why does this happen, and how can I fix/stop it?

    Seriously, this would have made a wonderful HDR thingie. But it ended up with all that...muck in it.

    http://smg.photobucket.com/albums/v6...nt-mantiuk.jpg

  2. #2
    neverhood311's Avatar
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    Re: Why does this happen, and how can I fix/stop it?

    I had the same problem. It usually happens in really bright spots that are next to fairly dark spots. I'm not exactly sure why they happen; it could be the ripples of the water causing a slight difference in each shot, so the tone mapper gets confused, but also happens when you use a tripod and shoot things that are stationary. I've found that if I compile the HDR in Photoshop, then tonemap in qtpfsgui (which I see you've been using) I get alot fewer artifacts.

    This link may help you.
    Avoiding HDR artifacts?

  3. #3

    Re: Why does this happen, and how can I fix/stop it?

    This is how it looks at pixel level at 3200%. It's the vertical reflection (the one on the right) under the bridge. It seems as if very bright pixels have been given very dark pixels, right down to black. How did you produce this? Have you still got the RAW? Can you post it HERE so we can try it out?

    HDR color problems near highlights - why does this happen, and how can I fix/stop it?

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    Re: Why does this happen, and how can I fix/stop it?

    Quote Originally Posted by carregwen View Post
    This is how it looks at pixel level at 3200%. It's the vertical reflection (the one on the right) under the bridge. It seems as if very bright pixels have been given very dark pixels, right down to black. How did you produce this? Have you still got the RAW? Can you post it HERE so we can try it out?

    HDR color problems near highlights - why does this happen, and how can I fix/stop it?
    The actual raw files, or the tiffs from which the HDR was made?

  5. #5

    Re: Why does this happen, and how can I fix/stop it?

    Quote Originally Posted by Quasarsphere View Post
    The actual raw files, or the tiffs from which the HDR was made?
    The RAW file(s).

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    Re: Why does this happen, and how can I fix/stop it?

    Quote Originally Posted by carregwen View Post
    The RAW file(s).
    OK, that upload site was annoying, so I put them on YouSendIt.

    https://www.yousendit.com/download/T...aFJGOFN4dnc9PQ

  7. #7

    Re: Why does this happen, and how can I fix/stop it?

    Quasarsphere (You might want to put your first name in your profile.)

    Thanks for putting up the files. The first thing I noticed was that there was a time lapse of 62 secs between first and last of the five RAW files. Because there is movement here that may (and has) caused some problems. Under the bridge there appears to be a row-boat moving from right to left, which has got smudged in the 62 secs. Personally, I use bracketing and take three shots, not five. That way you can put the mirror up, and put the camera on auto-timer. It will take the three shots in a few seconds. Also the water, especially where you had the problem, is well lit and will show up movement. Here is a screen-grab of my finished HDR - you can see the boat.

    HDR color problems near highlights - why does this happen, and how can I fix/stop it?

    The second thing I noticed was that the images are perfectly aligned in the HDR program. You must have a very steady tripod, and it must have been very calm, because there is no alignment overlap.

    I download the files, made some minor tweaks in CS4 RAW edit, synchronised them, and output them to PSD files. Then fed them into Dynamic Photo HDR. I used the 'Eye-catching' option, which is fairly subtle for HDR as I wanted to keep it looking like a normal shot, but with a better tonal range. Post HDR I used CS4 to make some minor corrections to contrast, sharpening of the central area, and used Neat Image to reduce the noise. There was a fair bit of noise due to the nature of the shot. Here is my final result. I don't have the artifacts that you had. There is some smudginess in the areas that you had a problem with, but that's to be expected given the 62 secs, and I thing it's quite acceptable. I suggest you try it again with a different HDR program, if you have one.

    It's a nice shot. Well taken.

    I'm sure Colin could (and probably will) do better.

    HDR color problems near highlights - why does this happen, and how can I fix/stop it?

  8. #8
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    Re: Why does this happen, and how can I fix/stop it?

    Dude, thanks very much indeed! And I love what you did with it too!

    Quote Originally Posted by carregwen View Post
    Thanks for putting up the files. The first thing I noticed was that there was a time lapse of 62 secs between first and last of the five RAW files. Because there is movement here that may (and has) caused some problems. Under the bridge there appears to be a row-boat moving from right to left, which has got smudged in the 62 secs. Personally, I use bracketing and take three shots, not five. That way you can put the mirror up, and put the camera on auto-timer. It will take the three shots in a few seconds. Also the water, especially where you had the problem, is well lit and will show up movement. Here is a screen-grab of my finished HDR - you can see the boat.
    Ah, yeah. The boat was the reason for the 62 seconds - I was waiting for it to go past and get far away enough for me to take the shot.

    Quote Originally Posted by carregwen View Post
    The second thing I noticed was that the images are perfectly aligned in the HDR program. You must have a very steady tripod, and it must have been very calm, because there is no alignment overlap.
    Yesterday was a very rare day for Wellington - no wind at all! That's how I was able to get this - http://lordlucan.deviantart.com/art/...rk-1-171481316

    And my tripod is surprisingly good for this sort of thing. It's a cheap, tiny thing - if I want to take a photo over a fence or something, I tend to be SOL. But given that my camera does not have AEB, and I have to take each exposure individually, changing the settings each time and then hitting the shutter button, it does a pretty damn good job!

    Quote Originally Posted by carregwen View Post
    I download the files, made some minor tweaks in CS4 RAW edit, synchronised them, and output them to PSD files. Then fed them into Dynamic Photo HDR. I used the 'Eye-catching' option, which is fairly subtle for HDR as I wanted to keep it looking like a normal shot, but with a better tonal range. Post HDR I used CS4 to make some minor corrections to contrast, sharpening of the central area, and used Neat Image to reduce the noise. There was a fair bit of noise due to the nature of the shot. Here is my final result. I don't have the artifacts that you had. There is some smudginess in the areas that you had a problem with, but that's to be expected given the 62 secs, and I thing it's quite acceptable. I suggest you try it again with a different HDR program, if you have one.
    Right now I'm using QTPFSGUI for everything. It seems to be quite crap for doing the HDR blend, but I do love its tone mappers. Especially Mantiuk, that one's just plain SEXY! However, I find that I really need to take 13 exposures, going from -2 to +2 in 1/3 stop intervals, to avoid the yucky artifacts. But I really don't mind doing that. For one thing, if someone should happen by and see me taking all these shots, it gives them the impression that I know what I'm doing. The fools! Mwahahahaha! Uhh...anyway, the only reason I didn't do that with this shot was that I was running out of time. And blocking the pathway.

    I've been trying to use Hugin to do the HDR-ification, but I have no idea how to make it work, and the results are just plain awful. I shall keep trying, though.

    I'm a Linux user, so my options are limited.

    Quote Originally Posted by carregwen View Post
    It's a nice shot. Well taken.
    Thank you very much indeed!

    Quote Originally Posted by carregwen View Post
    I'm sure Colin could (and probably will) do better.
    Well, I really like what you did with it.

    Cheers!

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