redcrown Offline Upload & Sell: Off
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I have the 16-35 and a 24-105. Use both to shoot a few HDR sequences. Three to five exposure brackets. I've found the Photoshop auto-align to be hit or miss. Mostly good, but maybe 1 out of 20 sets simply won't align. I've never figured out why, but I suspect it's because of exposure differences.
When Photoshop is trying to align the highest plus exposure shot and large portions of that shot are blown or close to blown, maybe it can't line up enough detail with the other, lower exposure shots to do the alignment. Maybe ditto for the lowest exposure shots where detail is mostly blocked up and gone.
I remember once, long ago, I had a landscape set with 2/3 bright cloudy sky. In the two top exposure shots that sky was mostly blown out. The 5 layers would not align. So I selected the sky and filled it with 50% gray on each layer, then tried again. The layers then aligned OK, with only the foreground to use.
That does not explain why your 24mm shots are OK but the 16-35 are not. Unless the 16-35 shots have wide exposure differences in key areas of the image. For example, are there very bright "flash" areas that are trying to align with very dark areas in the ambient shot?
Also related, the Lightroom/ACR "Upright" tool often gives significantly different results on different exposures of a well aligned bracketed set. Makes sense, I think, since Upright depends on finding vertical and horizontal elements, and those elements will be more or less prominent depending on exposure.
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