Sharpen Overload...

[Pehpsi]

hey,

i use aperture and think it's great, only problem is the sharpening tools suck.

i'm going to export to PS CS2 for my sharpening needs now, but there is 5 different tools to sharpen...

why so many, and which should i use to get my images nice and crisp?

just looking for a bit of advice, cheers

james.

[lukeo]

unsharp mask

google for some tutorials on its usage, i think there may even be a sharpening tutorial available from here.

[Pehpsi]

cheers, yraen69.

just gave it a workout, and it works pretty dam good...

[lukeo]

no problem, easy to use, hard to master, the discussion's on sharpening are endless.

Personally I find Strength of 25 to 75%, radius 0.5, threshold 2 or 3 works for me, sometimes applied twice as needed. Each image is different.

Beware of OVER Sharpening

[Steffen]

i use aperture and think it's great, only problem is the sharpening tools suck.

Which version of aperture and, assuming 1.5.x, which of the three sharpening tools?

The only ones I use are the one under RAW fine-tuning (which is subtle, as one would expect) and the Edge Sharpen tool. I don't use the other one (just called Sharpen). Incidentally, Edge Sharpen doesn't show in the adjustment HUD by default. I made it appear in there and got rid of Sharpen.

Edge Sharpen works very well and without amplifying noise (unlike unsharp mask). With the falloff slider you can very effectively control halos.

Cheers
Steffen.

[Pehpsi]

hey, steffen,

i used the 'edge sharpen' by itself and it does work quite well! my problem was with the the normal 'sharpen' tool, which i dont like very much.

i'll have a play with the edge tool and see how i go...

cheers.

[Steffen]

Yes, the old Sharpen tool wasn't really useful. Edge Sharpen was introduced later in response to user complaints, but curiously not made the default. I find that it works really well (better than BibblePro's sharpening), and is more likely to produce palatable and halo-free results.

I've got a text clipping on my Desktop, forgot where from. Here it is for your pleasure:

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Basics

The Edge Sharpen adjustment in Aperture is a professional tool that's used to sharpen photos. Unlike some sharpeners, Edge Sharpen has four special characteristics:

Only edges are sharpened
Edge Sharpen computes an edge mask and uses it to constrain the results of the sharpening operation. This means that, with the right settings, you should be able to sharpen your image without bringing up the texture in the noise, or in the sky. This can be useful in sharpening the edges of a face without introducing pockmarks.
Only image luminance is sharpened
Typical sharpeners work in the RGB color space. This can cause unusual colors to appear. So Edge Sharpen performs its sharpening only on the luminance information of the image, leaving the hue and saturation alone.
Image luminance is sharpened in a perceptual space
Sharpening should be accomplished in a space that has equal steps for equal perceptual steps. The Aperture Edge Sharpen adjustment does this so that the sharpening effect will be approximately the same in shadow areas as it is in the midtones.
Three sharpening passes are employed
It has often been mentioned on professional photography sites that typical sharpening algorithms can be improved by using several small sharpening steps with lower intensity. Usually the visual improvement is a decrease in the "ringing" around hard edges. These three sharpening passes are accomplished at different pixel radii (you can think of them as 1, 2, and 4 pixels, although their exact radii, actually standard deviations, are slightly different). Also, each sharpening pass uses a lowered intensity to purposefully avoid excessive "ringing" around edges. The relative contributions of each sharpening pass can be controlled using the Falloff slider.

Note: The 1, 2, and 4 scales were chosen specifically because they straddle the typical sharpening radius for a digital camera image (2.2 pixels).

Parameters

You can control Edge Sharpen to get professional results.

Intensity
The Intensity slider controls the overall amount of sharpening applied. Drag the Intensity slider to the right to increase the amount of sharpening applied to the image, and drag the Intensity slider back to the left to reduce it.

Edges
The Edges slider controls which pixels are edges and which are not. Drag the Edges slider to the right to increase the number of pixels that qualify as edges, and drag the Edges slider back to the left to restrict sharpening further. If you see noise increasing in a flat area of the image, like the sky, decrease the Edges parameter value.

Falloff
The Falloff slider controls how much sharpening is applied during the three sharpening passes at 1, 2, and 4 pixels respectively. Usually, the most sharpening happens in the 1-pixel pass, less in the 2-pixel pass, and less still in the 4-pixel pass. Drag the Falloff slider to the right to equalize the amount of sharpening power between the three sharpening radii, and drag the Falloff slider back to the left to increase the total sharpening power proportionately at the smallest features. Typically you should set the falloff parameter to a value between 0.4 and 0.7; a value of 0.7 means that, proportionately, only 70 percent of the sharpening power applied at the 1-pixel scale is applied at the 2-pixel scale, and only 49 percent of the 1-pixel scale sharpening is applied at the 4-pixel scale. Note that total intensity (between the three passes) always adds up to the indicated value of the Intensity slider.

Workflow

To sharpen an image:
Set the Intensity slider to the maximum value to see the effect of the operation.
Adjust the Edges slider so you can see which parts of the image are being sharpened. If possible, adjust the Edges slider so that edges are sharpened, but noise and texture in the image are not affected.
Adjust the Falloff slider so that the edge sizes you want sharpened the most are accentuated.
Decrease the Intensity parameter value until the sharpening effect is appropriately subtle. Usually a value of 0.5 is too much.
Edge Sharpen and RAW Edge Sharpening

You can control the amount of sharpening applied in the RAW demosaic process as well. It is controlled by the Intensity and Edges sliders in the RAW Fine Tuning adjustment. This sharpening is generally applied to all your RAW files, so you might want to turn it down (or off) and apply sharpening as an adjustment later. If you want sharpening applied automatically as part of your RAW workflow, leave the settings at the default values. They are intended to "undo" the effect of the camera's internal anti-aliasing filter and provide a suitably sharp image right out of RAW conversion.

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Cheers
Steffen.

[Pehpsi]

some great advice there thanks.

i sharpened an image in aperture using the edge tool, then did the same image in PS using unsharp mask and got a very similar end result, so im happy about that..

[Gordon]

unsharp mask

its interesting that this used to be a tool used by astronomers with photos to bring out details within "overexposed" areas of a photo, such as the bright inner regions of a nebula or galaxy that would otherwise appear as pure white on a photo printed to show the faint outer areas. Basically, an out of focus copy was made (contact copy with a diffuse light source, and the neg not quite in contact with the copying negative), so that you had a blurred positive of your negative. Then you printed from the sandwich of these 2 negs to effectively increase the dynamic rage of the print.
These days you set a couple of parameters and click an icon or 2, and Bob's yer mother's brother. The original method of unsharp masking also produced haloes like the computerised version if the mask was too strong.