Sunday, June 17, 2012 at 2:00 PM by Joseph Linaschke Devignette vs Negative Vignette in Aperture 3.3
One of the enhancements in Aperture 3.3 is that the Vignette adjustment can now can go negative, effectively devignetting an image. However there’s an important difference between the pre-existing Devignette adjustment and the new negative Vignette ability.
Devignette
Devignette is applied to the image pre-crop. The purpose of devignette is to remove a shadow (vignette) around the outer edges of a photo caused by either a lens shade or even the lens barrel itself on some extremely wide angle lenses. While we will often add a vignette to our photos as an effect, if you need to crop your image, then the natural vignette may not be your friend.
Original image with clear shadowing from the lens hood (tap to view larger)
In the photo above, you can clearly see a natural vignette appearing on the image. The only adjustment made thus far is curves, which has actually amplified the shadow. In the screenshot below, the Devignette adjustment has been applied, and turned up quite high (too high, really, but I wanted it to be clear here).
Same photo with devignette applied to remove the lens hood shadow (tap to view larger)
(Negative) Vignette
A negative vignette, on the other hand, is applied after the crop. So if you crop the image in any way, negative vignette won’t accurately remove that shadow. For example, if you cropped into the corner of your original image and tried to use this tool to remove that existing shadow, you could end up with a very odd vignette indeed.
So negative vignette is more useful as an effect than a correction, perhaps to make a dreamy look to your photos or to otherwise brighten the entire outer edge. When playing with it, be sure to experiment with both Gamma and Exposure settings, as the results are quite different.
Reader Comments (2)
You can go from -20 to +20 as well using the hover over numbers technique with the Vignette brick as well. Never quite understood why Apple decided to 'hide' the full scale.
I like the simplification.
I think the reason that Apple restricts the range on the sliders is because it makes it MUCH easter to get more control over a slider because you can be more precise easily. If it had a full -/+ 100 range then it would be more difficult to make more granular adjustments, which are more common for a vignette. Even though a range of 0-100 is more difficult to control than -/+ 20, it would be worth losing the precision on say a saturation control because the intuition of the saturation is to go from fully saturated to none at all.