Photomatix - Bad colour fringing

[nl74]

I decided recently to give HDR photography a serious go.  I have never been a fan of grads and HDR seems to offer an interesting new twist.
 
Anyway I have got photomatix tone mapping plug-in for mac and have been generating the HDR file in CS3.  I tried something quite simple at first mid-afternoon photograph of a lake taken on a sunny day, 3 exposures to capture the lake and keep the sky nice and blue.  Initially I was very pleased but upon zooming in I see what can only be described as severe colour fringing (purple) and a colour cast (yellow) in the sky part of the photo around the clouds. This was not present in the pre-HDR images.
 
Any experts out there have any ideas?
 
Thanks

[Gordon Buck]

I use the Photomatix plugin but make no claims on expertise.  Sometimes "bad" results from Photomatix are often a result of using extremes in the settings.  Try the default settings as a reference point.  That said, sometimes those extreme settings give the unique look that you might be seeking.

If the scene does not really require HDR then forcing HDR may not yield a desirable image.  Take a close look at the histogram of the "best" exposure from your bracketed shots.  If that histogram does not show a lot of underexposed areas or overexposed areas, then HDR may not be needed.  In that case, if you attempt to force the "HDR" look, the result may not be what you want.

Be sure to check the obvious:  Did you use a tripod?  Are the three images aligned?  It seems to me that CS3 auto-alignment is better than the Photomatix (standalone version) alignment.  But sometimes auto-alignment is a problem.

[nl74]

I use the Photomatix plugin but make no claims on expertise.  Sometimes "bad" results from Photomatix are often a result of using extremes in the settings.  Try the default settings as a reference point.  That said, sometimes those extreme settings give the unique look that you might be seeking.

If the scene does not really require HDR then forcing HDR may not yield a desirable image.  Take a close look at the histogram of the "best" exposure from your bracketed shots.  If that histogram does not show a lot of underexposed areas or overexposed areas, then HDR may not be needed.  In that case, if you attempt to force the "HDR" look, the result may not be what you want.

Be sure to check the obvious:  Did you use a tripod?  Are the three images aligned?  It seems to me that CS3 auto-alignment is better than the Photomatix (standalone version) alignment.  But sometimes auto-alignment is a problem.
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Hello,

Yes I used a tripod and all images were aligned.

These particular images were borderline HDR and I could get a similar result from the 0ev file, similar but not quite as good.  Maybe I should try harder!

[Geoff Wittig]

Hello,

Yes I used a tripod and all images were aligned.

These particular images were borderline HDR and I could get a similar result from the 0ev file, similar but not quite as good.  Maybe I should try harder!
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The problem is not HDR imaging or Photomatix per se. When you take multiple exposures of a real world subject, anything moving in the scene will be slightly out of register on successive frames. When combined in your HDR software of choice, you will consistently get bizarre artifacts at the edges of clouds because they are moving between frames in any condition but absolute dead still air. Which almost never happens.

[Gordon Buck]

Use a cable release and auto bracketing to get three shots in a very short period of time without touching the camera in-between shots.

[Guillermo Luijk]

Some sample would help.

[Woodcorner]

There's an interesting article on Outbackphoto.com regarding a technique called 'High Speed HDR' to avoid moving objects. It may also be used to simply have a series of bracketed shot swhen HDR is not really necessary.

High Speed HDR and Tone Mapping

Cheers,

Andrew

[Brentbat]

Your problem may not be misalignment (assuming you used tripod and cable release), but could well be accentuated chromatic abberation.  I found the same problem.

There is an interesting article about this on Outback Photo (different from the previous article).  You can check it out here http://www.outbackphoto.com/CONTENT_2007_0...oHDR/index.html

HDR can be great, but it here's what I'm finding,  I will often create an HDR base layer of a high dynamic range scene, and then I will overlay sections of the original image over the top in certain areas. I find this gives me a softer image at the end.  Here's an example.




I hope this helps.

BP

[craigwashburn]

I decided recently to give HDR photography a serious go.  I have never been a fan of grads and HDR seems to offer an interesting new twist.
 
Anyway I have got photomatix tone mapping plug-in for mac and have been generating the HDR file in CS3.  I tried something quite simple at first mid-afternoon photograph of a lake taken on a sunny day, 3 exposures to capture the lake and keep the sky nice and blue.  Initially I was very pleased but upon zooming in I see what can only be described as severe colour fringing (purple) and a colour cast (yellow) in the sky part of the photo around the clouds. This was not present in the pre-HDR images.
 
Any experts out there have any ideas?
 
Thanks
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HDR is all about problem solving.  Getting near perfect results is tricky and no two images are alike.   First note that any compromises in the camera or lens will be exagerrated - lens chromatic aberration shows up very easily, as can noise in dark areas.  You are probably seeing the results of some blooming CA or flare when doing the bright exposure.   Using the highest quality lenses without filters on the front has the best results.  As does using cameras with exceptionally low noise profiles.

The sky part around the clouds is probably the transition from the light cloud to the dark sky - this halo can be tweaked with software settings.

Then theres the issue of movement in the lake and clouds... photomatix has a new movement detector option, but I find it doesn't work very well and causes issues in static areas.