06-12-2010, 03:35 PM
I think from a quality point of view, it doesn't make a difference whether you stretch or squash. Bottom line is that you'll always lose resolution by correcting for distortion. Even if the image is stretched to compensate and maintain the pixel resolution, you don't actually gain anything over the squashed version because you need to stretch by interpolation, which doesn't give you real resolution. I guess personally I prefer the approach where you lose resolution, because you can then decide for yourself whether you want to stretch the picture later, and to what extent.
[quote name='DavidBM' date='12 June 2010 - 02:38 AM' timestamp='1276306731' post='447']
Does anyone know if the vertical perspective controls in LR3 exhibit the same behaviour as the CS4 and earlier ones? In particular, is the image squashed vertically? (PT lens, for example, stretches the image vertically to compensate).
Another issue: if you use the perspective controls, the top of the image will gradually fall outside the frame. You can compensate by scaling the image down - but this is not an ideal solution, since you are then losing resolution at the bottom of the image (and often it's just sky at the top so it doesn't matter much that it is interpolated heavily)
Only work around I can think of is to take the image to photoshop, expand the canvas, and then either bring it back or else use the lens correction in photoshop then. But it's just as rather use PTlens than go though all that.
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[quote name='DavidBM' date='12 June 2010 - 02:38 AM' timestamp='1276306731' post='447']
Does anyone know if the vertical perspective controls in LR3 exhibit the same behaviour as the CS4 and earlier ones? In particular, is the image squashed vertically? (PT lens, for example, stretches the image vertically to compensate).
Another issue: if you use the perspective controls, the top of the image will gradually fall outside the frame. You can compensate by scaling the image down - but this is not an ideal solution, since you are then losing resolution at the bottom of the image (and often it's just sky at the top so it doesn't matter much that it is interpolated heavily)
Only work around I can think of is to take the image to photoshop, expand the canvas, and then either bring it back or else use the lens correction in photoshop then. But it's just as rather use PTlens than go though all that.
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