Luminous Landscape Forum
Raw & Post Processing, Printing => Digital Image Processing => Topic started by: artHarris on February 03, 2010, 12:02:58 pm
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I have used the multi-shot function on my Canon Powershot S80 to produce some superb panoramas, but occasionally, mostly in clear blue sky, there is a band of differing colour shade at the joint. I don't know where to start to correct this.
I suppose I could do it with PSE 8, but can't work out how.
Any help much appreciated.
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I have used the multi-shot function on my Canon Powershot S80 to produce some superb panoramas, but occasionally, mostly in clear blue sky, there is a band of differing colour shade at the joint. I don't know where to start to correct this.
I suppose I could do it with PSE 8, but can't work out how.
Any help much appreciated.
How are you joining the shots?
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How are you joining the shots?
I am using the Stitch soft which came with the camera - PhotoStitch
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I am using the Stitch soft which came with the camera - PhotoStitch
Try AutoPano Pro or PTGUI, they stitch most skies without such issues. I think they both have free trials.
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If you shoot RAW, which you should anyway for a multitude of reasons, you can solve many blending issues by adjusting the vignette correction parameter in your RAW converter so that the color mismatch is prevented in the first place.
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It is also helpful if you lock the exposure setting so all panels have the same exposure. Select an exposure that does not quite clip the brightest parts of the sky.
But as mentioned vignetting is often the culprit in sky blending. If the S80 only outputs .jpgs you can still correct vignetting with "Filter->Distort->Lens Correction." Dunno if Elements has that, but CS4 does.
But if you're just trying to save a particular pano with a blue sky, you can also take a pair of samples of the sky colors, then make a partially transparent gradient wash on a separate layer. Keep the brightest parts of the sky wash at the bottom or on the side with the most light. Before doing that select the sky area and use it to make a reveal mask for the sky only on the gradient layer, sometimes help to blur the mask a little.
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Try AutoPano Pro or PTGUI, they stitch most skies without such issues. I think they both have free trials.
When using my Nikon D200, I do shoot RAW, but, unlike the other Powershot S series, the S80 doesn't have RAW capture facility - perhaps I should buy the new S90, which does.
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It is also helpful if you lock the exposure setting so all panels have the same exposure. Select an exposure that does not quite clip the brightest parts of the sky.
But as mentioned vignetting is often the culprit in sky blending. If the S80 only outputs .jpgs you can still correct vignetting with "Filter->Distort->Lens Correction." Dunno if Elements has that, but CS4 does.
But if you're just trying to save a particular pano with a blue sky, you can also take a pair of samples of the sky colors, then make a partially transparent gradient wash on a separate layer. Keep the brightest parts of the sky wash at the bottom or on the side with the most light. Before doing that select the sky area and use it to make a reveal mask for the sky only on the gradient layer, sometimes help to blur the mask a little.
Thank you - those sound like the kind of thing I should try; I'll look for that function in PSA, and will play with your second approach (when I have the time - right now, other things press)
Thanks again.
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Get a decent panorama stitcher.
In PSE8, I'd think AutoMerge does vignette removal like in CS4 (but I'm not sure).
Otherwise, Hugin is free and great.
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If possible on the S80, also switch off auto white balance. That may have caused differences as well.
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Thanks for all the helpful suggsetions - lots of options to try next time I get round to panoramas.
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I have used the multi-shot function on my Canon Powershot S80 to produce ........
If you shoot RAW, which you should anyway for a multitude of reasons, ......
Does the S80 have a raw option?
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Does the S80 have a raw option?
No, uniquely amongst that series, the S80 has no RAW option.
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Also, for a free and easy to use stitcher, Microsoft came out with ICE awhile back, http://research.microsoft.com/en-us/um/red...groups/ivm/ice/ (http://research.microsoft.com/en-us/um/redmond/groups/ivm/ice/) . It works much better than the stitcher that comes with Canon cameras. I always had issues using the OEM software, all my pano's you could see where they blended. Microsoft ICE was able to give me good results on all except one pano that I have tried with it.
If the 'multi-shot function ' is the panorama function then that should lock the exposure and focus (not sure about white balance). If it is not the panorama function then I would also try using that mode.
Also, normally find the brightest area in the panorama to take the 1st image (to lock the exposure to it) then start shooting. Just do not use that 1st image when building the pano. This normally keeps the highlights in check.
Also, another option is to use Auto or P mode (If you normally use one of those modes) and half click to focus and see exposure numbers (remember exposure numbers) then while 1/2 click press the MF button to lock focus. Then switch to M mode and set shutter speed and apeture to numbers shown when 1/2 click, also set white balance to daylight. Now everything is locked to shoot your images.
I never did use my pano mode on my P&S due to loosing 1/2 of the screen to 'align' the images. I did the method mentioned in the above paragraph. Just make sure you give enough overlap between images.
Tony